Adding upstream version 1.3+ds.upstream/1.3+dsupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

29 files changed, 6676 insertions, 0 deletions

diff --git a/src/io/CMakeLists.txt b/src/io/CMakeLists.txt
new file mode 100644
index 0000000..2d5198c
--- /dev/null
+++ b/src/io/CMakeLists.txt
@@ -0,0 +1,36 @@
+# SPDX-License-Identifier: GPL-2.0-or-later
+
+set(io_SRC
+  dir-util.cpp
+  file.cpp
+  file-export-cmd.cpp
+  resource.cpp
+  fix-broken-links.cpp
+  stream/bufferstream.cpp
+  stream/gzipstream.cpp
+  stream/inkscapestream.cpp
+  stream/stringstream.cpp
+  stream/uristream.cpp
+  stream/xsltstream.cpp
+  sys.cpp
+  http.cpp
+
+  # -------
+  # Headers
+  dir-util.h
+  file.h
+  file-export-cmd.h
+  resource.h
+  fix-broken-links.h
+  stream/bufferstream.h
+  stream/gzipstream.h
+  stream/inkscapestream.h
+  stream/stringstream.h
+  stream/uristream.h
+  stream/xsltstream.h
+  sys.h
+  http.h
+)
+
+# add_inkscape_lib(io_LIB "${io_SRC}")
+add_inkscape_source("${io_SRC}")
diff --git a/src/io/README b/src/io/README
new file mode 100644
index 0000000..9d971b7
--- /dev/null
+++ b/src/io/README
@@ -0,0 +1,35 @@
+
+This directory contains code related to input and output.
+
+
+Note that input and output to particular file formats may be implemented elsewhere:
+
+1. Internal extensions. See src/extensions/internal
+
+   Input:  CDR, EMF, WMF VSD WPG
+   Output: SVG, PNG (via Cairo), PS, EPS, PDF, POV, ODF, EMF, WMF, XAML, LaTex.
+
+2. External extensions (Python). See share/extensions
+
+   Input: PS, EPS, PDF, SK, XAML, DXF, DIA, AI, ?
+   Output: SVG (Layers/Optimized), SK1, XCF, HTML5, SIF, PTL, HPGL, DXF, FXG, XAML(?), CANVAS, ?
+
+3. SVG (XML) low level code: src/xml/repr-io.h
+
+
+To do:
+
+1. Move all file related code here (other than extensions).
+2. Move extension input/output code into subdirectories within src/extensions/internal and share/extensions.
+3. Separate out creating a document and creating a document window. The former belongs here, the later in src/ui.
+4. Use std::string for all file names and use glibmm file utilities.
+5. Use Glib::ustring for URI's and use Inkscape's URI utilities (if not available in glibmm).
+6. Rewrite file export code to share a common base and to allow easy export of objects. Should be Gio::Action based.
+   Things like cropping, selecting an object, hiding other objects, etc. should be done before the document is passed
+   to the file type specific export code. This way, we can use the same export options for all file types (where they
+   make sense). Only type specific options (e.g. PS Level) should be handled by the type specific code.
+
+
+Files to move here:
+  src/util/ziptool.h     (used by ODF, note SVG uses Inkscape::IO::GzipInputStream, can that be used instead?).
+  src/helper/png-write.h
diff --git a/src/io/dir-util.cpp b/src/io/dir-util.cpp
new file mode 100644
index 0000000..abd5c8f
--- /dev/null
+++ b/src/io/dir-util.cpp
@@ -0,0 +1,264 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * TODO: insert short description here
+ *//*
+ * Authors: see git history
+ *
+ * Copyright (C) 2018 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+/**
+ * @file
+ * Utility functions for filenames.
+ */
+
+#include <cerrno>
+#include <string>
+#include <cstring>
+#include <glib.h>
+#include "dir-util.h"
+
+std::string sp_relative_path_from_path( std::string const &path, std::string const &base)
+{
+    std::string result;
+    if ( !base.empty() && !path.empty() ) {
+        size_t base_len = base.length();
+        while (base_len != 0
+               && (base[base_len - 1] == G_DIR_SEPARATOR))
+        {
+            --base_len;
+        }
+
+        if ( (path.substr(0, base_len) == base.substr(0, base_len))
+             && (path[base_len] == G_DIR_SEPARATOR))
+        {
+            size_t retPos = base_len + 1;
+            while ( (retPos < path.length()) && (path[retPos] == G_DIR_SEPARATOR) ) {
+                retPos++;
+            }
+            if ( (retPos + 1) < path.length() ) {
+                result = path.substr(retPos);
+            }
+        }
+
+    }
+    if ( result.empty() ) {
+        result = path;
+    }
+    return result;
+}
+
+char const *sp_extension_from_path(char const *const path)
+{
+	if (path == nullptr) {
+		return nullptr;
+	}
+
+	char const *p = path;
+	while (*p != '\0') p++;
+
+	while ((p >= path) && (*p != G_DIR_SEPARATOR) && (*p != '.')) p--;
+	if (* p != '.') return nullptr;
+	p++;
+
+	return p;
+}
+
+
+/* current == "./", parent == "../" */
+static char const dots[] = {'.', '.', G_DIR_SEPARATOR, '\0'};
+static char const *const parent = dots;
+static char const *const current = dots + 1;
+
+char *inkscape_rel2abs(const char *path, const char *base, char *result, const size_t size)
+{
+  const char *pp, *bp;
+  /* endp points the last position which is safe in the result buffer. */
+  const char *endp = result + size - 1;
+  char *rp;
+  int length;
+  if (*path == G_DIR_SEPARATOR)
+    {
+      if (strlen (path) >= size)
+	goto erange;
+      strcpy (result, path);
+      goto finish;
+    }
+  else if (*base != G_DIR_SEPARATOR || !size)
+    {
+      errno = EINVAL;
+      return (nullptr);
+    }
+  else if (size == 1)
+    goto erange;
+  if (!strcmp (path, ".") || !strcmp (path, current))
+    {
+      if (strlen (base) >= size)
+	goto erange;
+      strcpy (result, base);
+      /* rp points the last char. */
+      rp = result + strlen (base) - 1;
+      if (*rp == G_DIR_SEPARATOR)
+	*rp = 0;
+      else
+	rp++;
+      /* rp point NULL char */
+      if (*++path == G_DIR_SEPARATOR)
+	{
+	  /* Append G_DIR_SEPARATOR to the tail of path name. */
+	  *rp++ = G_DIR_SEPARATOR;
+	  if (rp > endp)
+	    goto erange;
+	  *rp = 0;
+	}
+      goto finish;
+    }
+  bp = base + strlen (base);
+  if (*(bp - 1) == G_DIR_SEPARATOR)
+    --bp;
+  /* up to root. */
+  for (pp = path; *pp && *pp == '.';)
+    {
+      if (!strncmp (pp, parent, 3))
+	{
+	  pp += 3;
+	  while (bp > base && *--bp != G_DIR_SEPARATOR)
+	    ;
+	}
+      else if (!strncmp (pp, current, 2))
+	{
+	  pp += 2;
+	}
+      else if (!strncmp (pp, "..\0", 3))
+	{
+	  pp += 2;
+	  while (bp > base && *--bp != G_DIR_SEPARATOR)
+	    ;
+	}
+      else
+	break;
+    }
+  /* down to leaf. */
+  length = bp - base;
+  if (length >= static_cast<int>(size))
+    goto erange;
+  strncpy (result, base, length);
+  rp = result + length;
+  if (*pp || *(pp - 1) == G_DIR_SEPARATOR || length == 0)
+    *rp++ = G_DIR_SEPARATOR;
+  if (rp + strlen (pp) > endp)
+    goto erange;
+  strcpy (rp, pp);
+finish:
+  return result;
+erange:
+  errno = ERANGE;
+  return (nullptr);
+}
+
+char *inkscape_abs2rel(const char *path, const char *base, char *result, const size_t size)
+{
+    const char *pp, *bp, *branch;
+    // endp points the last position which is safe in the result buffer.
+    const char *endp = result + size - 1;
+    char *rp;
+
+    if (*path != G_DIR_SEPARATOR)
+    {
+        if (strlen (path) >= size)
+            goto erange;
+        strcpy (result, path);
+        goto finish;
+    }
+    else if (*base != G_DIR_SEPARATOR || !size)
+    {
+        errno = EINVAL;
+        return (nullptr);
+    }
+    else if (size == 1)
+        goto erange;
+    /* seek to branched point. */
+    branch = path;
+    for (pp = path, bp = base; *pp && *bp && *pp == *bp; pp++, bp++)
+        if (*pp == G_DIR_SEPARATOR)
+            branch = pp;
+    if (((*pp == 0) || ((*pp == G_DIR_SEPARATOR) && (*(pp + 1) == 0))) &&
+        ((*bp == 0) || ((*bp == G_DIR_SEPARATOR) && (*(bp + 1) == 0))))
+    {
+        rp = result;
+        *rp++ = '.';
+        if (*pp == G_DIR_SEPARATOR || *(pp - 1) == G_DIR_SEPARATOR)
+            *rp++ = G_DIR_SEPARATOR;
+        if (rp > endp)
+            goto erange;
+        *rp = 0;
+        goto finish;
+    }
+    if (((*pp == 0) && (*bp == G_DIR_SEPARATOR)) || ((*pp == G_DIR_SEPARATOR) && (*bp == 0)))
+        branch = pp;
+    /* up to root. */
+    rp = result;
+    for (bp = base + (branch - path); *bp; bp++)
+        if (*bp == G_DIR_SEPARATOR && *(bp + 1) != 0)
+        {
+            if (rp + 3 > endp)
+                goto erange;
+            *rp++ = '.';
+            *rp++ = '.';
+            *rp++ = G_DIR_SEPARATOR;
+        }
+    if (rp > endp)
+        goto erange;
+    *rp = 0;
+    /* down to leaf. */
+    if (*branch)
+    {
+        if (rp + strlen (branch + 1) > endp)
+            goto erange;
+        strcpy (rp, branch + 1);
+    }
+    else
+        *--rp = 0;
+finish:
+    return result;
+erange:
+    errno = ERANGE;
+    return (nullptr);
+}
+
+char *prepend_current_dir_if_relative(gchar const *uri)
+{
+	if (!uri) {
+		return nullptr;
+	}
+
+	gchar *full_path = (gchar *) g_malloc (1001);
+	gchar *cwd = g_get_current_dir();
+
+	gsize bytesRead = 0;
+	gsize bytesWritten = 0;
+	GError* error = nullptr;
+	gchar* cwd_utf8 = g_filename_to_utf8 ( cwd,
+                                                  -1,
+                                                  &bytesRead,
+                                                  &bytesWritten,
+                                                  &error);
+
+	inkscape_rel2abs (uri, cwd_utf8, full_path, 1000);
+	gchar *ret = g_strdup (full_path);
+  g_free(cwd_utf8);
+	g_free (full_path);
+	g_free (cwd);
+	return ret;
+}
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vi: set autoindent shiftwidth=4 tabstop=8 filetype=cpp expandtab softtabstop=4 fileencoding=utf-8 textwidth=99 :
diff --git a/src/io/dir-util.h b/src/io/dir-util.h
new file mode 100644
index 0000000..91f07c8
--- /dev/null
+++ b/src/io/dir-util.h
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * TODO: insert short description here
+ *//*
+ * Authors: see git history
+ *
+ * Copyright (C) 2016 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+#ifndef SEEN_DIR_UTIL_H
+#define SEEN_DIR_UTIL_H
+
+/*
+ * path-util.h
+ *
+ * here are functions sp_relative_path & cousins
+ * maybe they are already implemented in standard libs
+ *
+ */
+
+#include <cstdlib>
+#include <string>
+
+/**
+ * Returns a form of \a path relative to \a base if that is easy to construct (eg if \a path
+ * appears to be in the directory specified by \a base), otherwise returns \a path.
+ *
+ * @param path is expected to be an absolute path.
+ * @param base is expected to be either empty or the absolute path of a directory.
+ *
+ * @return a relative version of the path, if reasonable.
+ *
+ * @see inkscape_abs2rel for a more sophisticated version.
+ * @see prepend_current_dir_if_relative.
+*/
+std::string sp_relative_path_from_path(std::string const &path, std::string const &base);
+
+char const *sp_extension_from_path(char const *path);
+
+/**
+ * Convert a relative path name into absolute. If path is already absolute, does nothing except copying path to result.
+ *
+ * @param path relative path.
+ * @param base base directory (must be absolute path).
+ * @param result result buffer.
+ * @param size size of result buffer.
+ *
+ * @return != NULL: absolute path
+ *         == NULL: error
+ *
+ * based on functions by Shigio Yamaguchi.
+ * FIXME:TODO: force it to also do path normalization of the entire resulting path,
+ * i.e. get rid of any .. and . in any place, even if 'path' is already absolute
+ * (now it returns it unchanged in this case)
+ *
+ */
+char *inkscape_rel2abs(char const *path, char const *base, char *result, size_t const size);
+
+char *inkscape_abs2rel(char const *path, char const *base, char *result, size_t const size);
+
+char *prepend_current_dir_if_relative(char const *filename);
+
+
+#endif // !SEEN_DIR_UTIL_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/io/file-export-cmd.cpp b/src/io/file-export-cmd.cpp
new file mode 100644
index 0000000..1663a82
--- /dev/null
+++ b/src/io/file-export-cmd.cpp
@@ -0,0 +1,960 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * File export from the command line. This code, greatly modified, use to be in main.cpp. It should
+ * be replaced by code shared with the file dialog (Gio::Actions?).
+ *
+ * Copyright (C) 2018 Tavmjong Bah
+ *
+ * Git blame shows that bulia byak is the main author of the original export code from
+ * main.cpp. Other authors of note include Nicolas Dufour, Vinicius dos Santos Oliveira, and Bob
+ * Jamison; none of whom bothered to add their names to the copyright of main.cc.
+ *
+ * The contents of this file may be used under the GNU General Public License Version 2 or later.
+ *
+ */
+
+#include "file-export-cmd.h"
+
+#include <boost/algorithm/string.hpp>
+#include <iostream>
+#include <png.h> // PNG export
+#include <string>
+
+#include "document.h"
+#include "extension/db.h"
+#include "extension/extension.h"
+#include "extension/init.h"
+#include "extension/output.h"
+#include "extension/system.h"
+#include "helper/png-write.h" // PNG Export
+#include "object/object-set.h"
+#include "object/sp-flowtext.h"
+#include "object/sp-item.h"
+#include "object/sp-namedview.h"
+#include "object/sp-object-group.h"
+#include "object/sp-page.h"
+#include "object/sp-root.h"
+#include "object/sp-text.h"
+#include "page-manager.h"
+#include "path-chemistry.h"      // sp_item_list_to_curves
+#include "selection-chemistry.h" // fit_canvas_to_drawing
+#include "svg/svg-color.h"       // Background color
+#include "text-editing.h"        // te_update_layout_now_recursive
+#include "util/parse-int-range.h"
+#include "io/sys.h"
+
+// Temporary dependency : once all compilers we want to support have support for
+// C++17 std::filesystem (with #include <filesystem> ) then we drop this dep
+// (Dev meeting, 2020-09-25)
+
+#ifdef G_OS_WIN32
+#include <filesystem>
+namespace filesystem = std::filesystem;
+#else
+#include <boost/filesystem.hpp>
+namespace filesystem = boost::filesystem;
+#endif
+
+InkFileExportCmd::InkFileExportCmd()
+    : export_overwrite(false)
+    , export_margin(0)
+    , export_area_snap(false)
+    , export_use_hints(false)
+    , export_width(0)
+    , export_height(0)
+    , export_dpi(0)
+    , export_ignore_filters(false)
+    , export_text_to_path(false)
+    , export_ps_level(3)
+    , export_pdf_level("1.5")
+    , export_latex(false)
+    , export_id_only(false)
+    , export_background_opacity(-1) // default is unset != actively set to 0
+    , export_plain_svg(false)
+{
+}
+
+void
+InkFileExportCmd::do_export(SPDocument* doc, std::string filename_in)
+{
+    std::string export_type_filename;
+    std::vector<Glib::ustring> export_type_list;
+
+    // Get export type from filename supplied with --export-filename
+    if (!export_filename.empty() && export_filename != "-") {
+
+        // Attempt to result variable and home path use in export filenames.
+        Glib::RefPtr<Gio::File> gfile = Gio::File::create_for_parse_name(export_filename);
+        export_filename = gfile->get_parse_name();
+
+#ifdef G_OS_WIN32
+        auto fn = filesystem::u8path(export_filename);
+#else
+        auto fn = filesystem::path(export_filename);
+#endif
+        if (!fn.has_extension()) {
+            if (export_type.empty() && export_extension.empty()) {
+                std::cerr << "InkFileExportCmd::do_export: No export type specified. "
+                          << "Append a supported file extension to filename provided with --export-filename or "
+                          << "provide one or more extensions separately using --export-type" << std::endl;
+                return;
+            } else {
+                // no extension is fine if --export-type is given
+                // explicitly stated extensions are handled later
+            }
+        } else {
+            export_type_filename = fn.extension().string().substr(1);
+            boost::algorithm::to_lower(export_type_filename);
+            export_filename = (fn.parent_path() / fn.stem()).string();
+        }
+    }
+
+    // Get export type(s) from string supplied with --export-type
+    if (!export_type.empty()) {
+        export_type_list = Glib::Regex::split_simple("[,;]", export_type);
+    }
+
+    // Determine actual type(s) for export.
+    if (export_use_hints) {
+        // Override type if --export-use-hints is used (hints presume PNG export for now)
+        // TODO: There's actually no reason to presume. We could allow to export to any format using hints!
+        if (export_id.empty() && export_area_type != ExportAreaType::Drawing) {
+            std::cerr << "InkFileExportCmd::do_export: "
+                      << "--export-use-hints can only be used with --export-id or --export-area-drawing." << std::endl;
+            return;
+        }
+        if (export_type_list.size() > 1 || (export_type_list.size() == 1 && export_type_list[0] != "png")) {
+            std::cerr << "InkFileExportCmd::do_export: --export-use-hints can only be used with PNG export! "
+                      << "Ignoring --export-type=" << export_type.raw() << "." << std::endl;
+        }
+        if (!export_filename.empty()) {
+            std::cerr << "InkFileExportCmd::do_export: --export-filename is ignored when using --export-use-hints!" << std::endl;
+        }
+        export_type_list.clear();
+        export_type_list.emplace_back("png");
+    } else if (export_type_list.empty()) {
+        if (!export_type_filename.empty()) {
+            export_type_list.emplace_back(export_type_filename); // use extension from filename
+        } else if (!export_extension.empty()) {
+            // guess export type from extension
+            auto ext =
+                dynamic_cast<Inkscape::Extension::Output *>(Inkscape::Extension::db.get(export_extension.data()));
+            if (ext) {
+                export_type_list.emplace_back(std::string(ext->get_extension()).substr(1));
+            } else {
+                std::cerr << "InkFileExportCmd::do_export: "
+                          << "The supplied --export-extension was not found. Specify a file extension "
+                          << "to get a list of available extensions for this file type.";
+                return;
+            }
+        } else {
+            export_type_list.emplace_back("svg"); // fall-back to SVG by default
+        }
+    }
+    // Export filename should be used when specified as the output file
+    if (export_filename.empty()) {
+        export_filename = filename_in;
+    }
+    // check if multiple export files are requested, but --export_extension was supplied
+    if (!export_extension.empty() && export_type_list.size() != 1) {
+        std::cerr
+            << "InkFileExportCmd::do_export: You may only specify one export type if --export-extension is supplied";
+        return;
+    }
+    Inkscape::Extension::DB::OutputList extension_list;
+    Inkscape::Extension::db.get_output_list(extension_list);
+
+    for (auto const &Type : export_type_list) {
+        // use lowercase type for following comparisons
+        auto type = Type.lowercase();
+        g_info("exporting '%s' to type '%s'", filename_in.c_str(), type.c_str());
+
+        export_type_current = type;
+
+        // Check for consistency between extension of --export-filename and --export-type if both are given
+        if (!export_type_filename.empty() && (type != export_type_filename)) {
+            std::cerr << "InkFileExportCmd::do_export: "
+                      << "Ignoring extension of export filename (" << export_type_filename << ") "
+                      << "as it does not match the current export type (" << type.raw() << ")." << std::endl;
+        }
+        bool export_extension_forced = !export_extension.empty();
+        // For PNG export, there is no extension, so the method below can not be used.
+        if (type == "png") {
+            if (!export_extension_forced) {
+                do_export_png(doc, export_filename);
+            } else {
+                std::cerr << "InkFileExportCmd::do_export: "
+                          << "The parameter --export-extension is invalid for PNG export" << std::endl;
+            }
+            continue;
+        }
+        // for SVG export, we let the do_export_svg function handle the selection of the extension, unless
+        // an extension ID was explicitly given. This makes handling of --export-plain-svg easier (which
+        // should also work when multiple file types are given, unlike --export-extension)
+        if (type == "svg" && !export_extension_forced) {
+            do_export_svg(doc, export_filename);
+            continue;
+        }
+
+        bool extension_for_fn_exists = false;
+        bool exported = false;
+        // if no extension is found, the entire list of extensions is walked through,
+        // so we can use the same loop to construct the list of available formats for the error message
+        std::list<std::string> filetypes({".svg", ".png", ".ps", ".eps", ".pdf"});
+        std::list<std::string> exts_for_fn;
+        for (auto oext : extension_list) {
+            if (oext->deactivated()) {
+                continue;
+            }
+            auto name = Glib::ustring(oext->get_extension()).lowercase();
+            filetypes.emplace_back(name);
+            if (name == "." + type) {
+                extension_for_fn_exists = true;
+                exts_for_fn.emplace_back(oext->get_id());
+                if (!export_extension_forced ||
+                    (export_extension == Glib::ustring(oext->get_id()).lowercase())) {
+                    if (type == "svg") {
+                        do_export_vector(doc, export_filename, *oext);
+                    } else if (type == "ps") {
+                        do_export_ps_pdf(doc, export_filename, "image/x-postscript", *oext);
+                    } else if (type == "eps") {
+                        do_export_ps_pdf(doc, export_filename, "image/x-e-postscript", *oext);
+                    } else if (type == "pdf") {
+                        do_export_ps_pdf(doc, export_filename, "application/pdf", *oext);
+                    } else {
+                        do_export_extension(doc, export_filename, oext);
+                    }
+                    exported = true;
+                    break;
+                }
+            }
+        }
+        if (!exported) {
+            if (export_extension_forced && extension_for_fn_exists) {
+                // the located extension for this file type did not match the provided --export-extension parameter
+                std::cerr << "InkFileExportCmd::do_export: "
+                          << "The supplied extension ID (" << export_extension
+                          << ") does not match any of the extensions "
+                          << "available for this file type." << std::endl
+                          << "Supported IDs for this file type: [";
+                copy(exts_for_fn.begin(), exts_for_fn.end(), std::ostream_iterator<std::string>(std::cerr, ", "));
+                std::cerr << "\b\b]" << std::endl;
+            } else {
+                std::cerr << "InkFileExportCmd::do_export: Unknown export type: " << type.raw() << ". Allowed values: [";
+                filetypes.sort();
+                filetypes.unique();
+                copy(filetypes.begin(), filetypes.end(), std::ostream_iterator<std::string>(std::cerr, ", "));
+                std::cerr << "\b\b]" << std::endl;
+            }
+        }
+    }
+}
+
+// File names use std::string. HTML5 and presumably SVG 2 allows UTF-8 characters. Do we need to convert "object_id" here?
+std::string
+InkFileExportCmd::get_filename_out(std::string filename_in, std::string object_id)
+{
+    // Pipe out
+    if (export_filename == "-") {
+        return "-";
+    }
+
+    auto const export_type_current_native = Glib::filename_from_utf8(export_type_current);
+
+    // Use filename provided with --export-filename if given
+    if (!export_filename.empty()) {
+        auto ext = Inkscape::IO::get_file_extension(export_filename);
+        auto cmp = "." + export_type_current_native;
+        return export_filename + (ext == cmp ? "" : cmp);
+    }
+
+    // Check for pipe
+    if (filename_in == "-") {
+        return "-";
+    }
+
+    // Construct output filename from input filename and export_type.
+    auto extension_pos = filename_in.find_last_of('.');
+    if (extension_pos == std::string::npos) {
+        std::cerr << "InkFileExportCmd::get_filename_out: cannot determine input file type from filename extension: " << filename_in << std::endl;
+        return (std::string());
+    }
+
+    std::string extension = filename_in.substr(extension_pos+1);
+    if (export_overwrite && export_type_current_native == extension) {
+        return filename_in;
+    } else {
+        std::string tag;
+        if (export_type_current_native == extension) {
+            tag = "_out";
+        }
+        if (!object_id.empty()) {
+            tag = "_" + object_id;
+        }
+        return filename_in.substr(0, extension_pos) + tag + "." + export_type_current_native;
+    }
+}
+
+/**
+ *  Perform an SVG export
+ *
+ *  \param doc Document to export.
+ *  \param export_filename Filename for export
+ */
+int InkFileExportCmd::do_export_svg(SPDocument *doc, std::string const &export_filename)
+{
+    Inkscape::Extension::Output *oext;
+    if (export_plain_svg) {
+        oext =
+            dynamic_cast<Inkscape::Extension::Output *>(Inkscape::Extension::db.get("org.inkscape.output.svg.plain"));
+    } else {
+        oext = dynamic_cast<Inkscape::Extension::Output *>(
+            Inkscape::Extension::db.get("org.inkscape.output.svg.inkscape"));
+    }
+    return do_export_vector(doc, export_filename, *oext);
+}
+/**
+ *  Perform a vector file export (SVG, PDF, or PS)
+ *
+ *  \param doc Document to export.
+ *  \param export_filename Filename for export
+ *  \param extension Output extension used for exporting
+ */
+int InkFileExportCmd::do_export_vector(SPDocument *doc, std::string const &export_filename,
+                                       Inkscape::Extension::Output &extension)
+{
+    // Start with options that are once per document.
+    if (export_text_to_path) {
+        Inkscape::convert_text_to_curves(doc);
+    }
+
+    if (export_margin != 0) {
+        gdouble margin = export_margin;
+        doc->ensureUpToDate();
+        SPNamedView *nv;
+        Inkscape::XML::Node *nv_repr;
+        if ((nv = doc->getNamedView()) && (nv_repr = nv->getRepr())) {
+            nv_repr->setAttributeSvgDouble("fit-margin-top", margin);
+            nv_repr->setAttributeSvgDouble("fit-margin-left", margin);
+            nv_repr->setAttributeSvgDouble("fit-margin-right", margin);
+            nv_repr->setAttributeSvgDouble("fit-margin-bottom", margin);
+        }
+    }
+
+    if (export_area_type == ExportAreaType::Drawing) {
+        fit_canvas_to_drawing(doc, export_margin != 0 ? true : false);
+    } else if (export_area_type == ExportAreaType::Page || export_id.empty()) {
+        if (export_margin) {
+            doc->ensureUpToDate();
+            doc->fitToRect(*(doc->preferredBounds()), export_margin);
+        }
+    }
+
+    // Export pages instead of objects
+    if (!export_page.empty()) {
+        std::string base = export_filename;
+        std::string ext = "svg";
+        // Strip any possible extension
+        std::string tmp_out = get_filename_out(export_filename, "");
+        auto extension_pos = tmp_out.find_last_of('.');
+        if (extension_pos != std::string::npos) {
+            base = tmp_out.substr(0, extension_pos);
+            ext = tmp_out.substr(extension_pos+1);
+        }
+
+        auto pages = Inkscape::parseIntRange(export_page);
+        for (auto page_num : pages) {
+            // And if only one page is selected then we assume the user knows the filename they intended.
+            std::string filename_out = base + (pages.size() > 1 ? "_p" + std::to_string(page_num) : "") + "." + ext;
+
+            auto copy_doc = doc->copy();
+            copy_doc->prunePages(std::to_string(page_num), true);
+            copy_doc->ensureUpToDate();
+            copy_doc->vacuumDocument();
+
+            try {
+                extension.set_gui(false);
+                Inkscape::Extension::save(dynamic_cast<Inkscape::Extension::Extension *>(&extension), copy_doc.get(),
+                                          filename_out.c_str(), false, false, Inkscape::Extension::FILE_SAVE_METHOD_SAVE_COPY);
+            } catch (Inkscape::Extension::Output::save_failed const &) {
+                std::cerr << "InkFileExportCmd::do_export_vector: Failed to save " << (export_plain_svg ? "" : "Inkscape")
+                          << " file to: " << filename_out << std::endl;
+                return 1;
+            }
+        }
+        return 0;
+    }
+
+    // Export each object in list (or root if empty).  Use ';' so in future it could be possible to selected multiple objects to export together.
+    std::vector<Glib::ustring> objects = Glib::Regex::split_simple("\\s*;\\s*", export_id);
+    if (objects.empty()) {
+        objects.emplace_back(); // So we do loop at least once for root.
+    }
+
+    for (auto object : objects) {
+        auto copy_doc = doc->copy();
+
+        std::string filename_out = get_filename_out(export_filename, Glib::filename_from_utf8(object));
+        if (filename_out.empty()) {
+            return 1;
+        }
+
+        if(!object.empty()) {
+            copy_doc->ensureUpToDate();
+
+            // "crop" the document to the specified object, cleaning as we go.
+            SPObject *obj = copy_doc->getObjectById(object);
+            if (obj == nullptr) {
+                std::cerr << "InkFileExportCmd::do_export_vector: Object " << object.raw() << " not found in document, nothing to export." << std::endl;
+                return 1;
+            }
+            if (export_id_only) {
+                // If -j then remove all other objects to complete the "crop"
+                copy_doc->getRoot()->cropToObject(obj);
+            }
+            if (export_area_type != ExportAreaType::Drawing && export_area_type != ExportAreaType::Page) {
+                Inkscape::ObjectSet s(copy_doc.get());
+                s.set(obj);
+                s.fitCanvas((bool)export_margin);
+            }
+        }
+        try {
+            extension.set_gui(false);
+            Inkscape::Extension::save(dynamic_cast<Inkscape::Extension::Extension *>(&extension), copy_doc.get(),
+                                      filename_out.c_str(), false, false,
+                                      export_plain_svg ? Inkscape::Extension::FILE_SAVE_METHOD_SAVE_COPY
+                                                       : Inkscape::Extension::FILE_SAVE_METHOD_INKSCAPE_SVG);
+        } catch (Inkscape::Extension::Output::save_failed &e) {
+            std::cerr << "InkFileExportCmd::do_export_vector: Failed to save " << (export_plain_svg ? "" : "Inkscape")
+                      << " file to: " << filename_out << std::endl;
+            return 1;
+        }
+    }
+    return 0;
+}
+
+guint32 InkFileExportCmd::get_bgcolor(SPDocument *doc) {
+    guint32 bgcolor = 0x00000000;
+    if (!export_background.empty()) {
+        // override the page color
+        bgcolor = sp_svg_read_color(export_background.c_str(), 0xffffff00);
+        // default is opaque if a color is given on commandline
+        if (export_background_opacity < -.5 ) {
+            export_background_opacity = 255;
+        }
+    } else {
+        // read from namedview
+        Inkscape::XML::Node *nv = doc->getReprNamedView();
+        if (nv && nv->attribute("pagecolor")){
+            bgcolor = sp_svg_read_color(nv->attribute("pagecolor"), 0xffffff00);
+        }
+    }
+
+    if (export_background_opacity > -.5) { // if the value is manually set
+        if (export_background_opacity > 1.0) {
+            float value = CLAMP (export_background_opacity, 1.0f, 255.0f);
+            bgcolor |= (guint32) floor(value);
+        } else {
+            float value = CLAMP (export_background_opacity, 0.0f, 1.0f);
+            bgcolor |= SP_COLOR_F_TO_U(value);
+        }
+    } else {
+        Inkscape::XML::Node *nv = doc->getReprNamedView();
+        if (nv && nv->attribute("inkscape:pageopacity")){
+            double opacity = nv->getAttributeDouble("inkscape:pageopacity", 1.0);
+            bgcolor |= SP_COLOR_F_TO_U(opacity);
+        } // else it's transparent
+    }
+    return bgcolor;
+}
+
+/**
+ *  Perform a PNG export
+ *
+ *  \param doc Document to export.
+ *  \param export_filename filename for export
+ */
+int
+InkFileExportCmd::do_export_png(SPDocument *doc, std::string const &export_filename)
+{
+    bool filename_from_hint = false;
+    gdouble dpi = 0.0;
+
+    auto prefs = Inkscape::Preferences::get();
+    bool old_dither = prefs->getBool("/options/dithering/value", true);
+    prefs->setBool("/options/dithering/value", export_png_use_dithering);
+
+    // Export each object in list (or root if empty).  Use ';' so in future it could be possible to selected multiple objects to export together.
+    std::vector<Glib::ustring> objects = Glib::Regex::split_simple("\\s*;\\s*", export_id);
+
+    std::vector<SPItem*> items;
+    std::vector<Glib::ustring> objects_found;
+    for (auto object_id : objects) {
+        // Find export object. (Either root or object with specified id.)
+        auto object = doc->getObjectById(object_id);
+
+        if (!object) {
+            std::cerr << "InkFileExport::do_export_png: "
+                      << "Object with id=\"" << object_id.raw()
+                      << "\" was not found in the document. Skipping." << std::endl;
+            continue;
+        }
+
+        if (!is<SPItem>(object)) {
+            std::cerr << "InkFileExportCmd::do_export_png: "
+                      << "Object with id=\"" << object_id.raw()
+                      << "\" is not a visible item. Skipping." << std::endl;
+            continue;
+        }
+
+        items.push_back(cast<SPItem>(object));
+        objects_found.push_back(object_id);
+    }
+
+    // Export pages instead of objects
+    if (!export_page.empty()) {
+        auto &pm = doc->getPageManager();
+        std::string base = export_filename;
+        // Strip any possible extension
+        auto extension_pos = export_filename.find_last_of('.');
+        if (extension_pos != std::string::npos)
+            base = export_filename.substr(0, extension_pos);
+
+        auto pages = Inkscape::parseIntRange(export_page);
+        for (auto page_num : pages) {
+            // We always use the png extension and ignore the extension given by the user
+            // And if only one page is selected then we assume the user knows the filename they intended.
+            std::string filename_out = base + (pages.size() > 1 ? "_p" + std::to_string(page_num) : "") + ".png";
+            if (auto page = pm.getPage(page_num - 1)) {
+                do_export_png_now(doc, filename_out, page->getDesktopRect(), dpi, items);
+            }
+        }
+        return 0;
+    }
+
+    if (objects.empty()) {
+        objects_found.emplace_back(); // So we do loop at least once for root.
+    }
+
+    for (auto object_id : objects_found) {
+        SPObject *object = doc->getRoot();
+        if (!object_id.empty()) {
+            object = doc->getObjectById(object_id);
+        }
+
+        std::string filename_out = get_filename_out(export_filename, Glib::filename_from_utf8(object_id));
+
+        if (export_id_only) {
+            std::cerr << "Exporting only object with id=\""
+                      << object_id.raw() << "\"; all other objects hidden." << std::endl;
+        }
+
+        // Find file name and dpi from hints.
+        if (export_use_hints) {
+
+            // Retrieve export filename hint.
+            const gchar *fn_hint = object->getRepr()->attribute("inkscape:export-filename");
+            if (fn_hint) {
+                filename_out = fn_hint;
+                filename_from_hint = true;
+            } else {
+                std::cerr << "InkFileExport::do_export_png: "
+                          << "Export filename hint not found for object " << object_id.raw() << ". Skipping." << std::endl;
+                continue;
+            }
+
+            // Retrieve export dpi hint. Only xdpi as ydpi is always the same now.
+            const gchar *dpi_hint = object->getRepr()->attribute("inkscape:export-xdpi");
+            if (dpi_hint) {
+                if (export_dpi || export_width || export_height) {
+                    std::cerr << "InkFileExport::do_export_png: "
+                              << "Using bitmap dimensions from the command line "
+                              << "(--export-dpi, --export-width, or --export-height). "
+                              << "DPI hint " << dpi_hint << " is ignored." << std::endl;
+                } else {
+                    dpi = g_ascii_strtod(dpi_hint, nullptr);
+                }
+            } else {
+                std::cerr << "InkFileExport::do_export_png: "
+                          << "Export DPI hint not found for the object." << std::endl;
+            }
+        }
+
+        // ------------------------- File name -------------------------
+
+        // Check we have a filename.
+        if (filename_out.empty()) {
+            std::cerr << "InkFileExport::do_export_png: "
+                      << "No valid export filename given and no filename hint. Skipping." << std::endl;
+            continue;
+        }
+
+        if (filename_from_hint) {
+            //Make relative paths go from the document location, if possible:
+            if (!Glib::path_is_absolute(filename_out) && doc->getDocumentFilename()) {
+                std::string dirname = Glib::path_get_dirname(doc->getDocumentFilename());
+                if (!dirname.empty()) {
+                    filename_out = Glib::build_filename(dirname, filename_out);
+                }
+            }
+        }
+
+        // Check if directory exists
+        std::string directory = Glib::path_get_dirname(filename_out);
+        if (!Glib::file_test(directory, Glib::FILE_TEST_IS_DIR)) {
+            std::cerr << "File path " << filename_out << " includes directory that doesn't exist. Skipping." << std::endl;
+            continue;
+        }
+
+        // -------------------------  Area -------------------------------
+
+        Geom::Rect area;
+        doc->ensureUpToDate();
+
+        if (export_area_type == ExportAreaType::Unset) {
+            // Default to drawing if has object, otherwise export page
+            if (object_id.empty()) {
+                export_area_type = ExportAreaType::Page;
+            } else {
+                export_area_type = ExportAreaType::Drawing;
+            }
+        }
+        // Three choices: 1. Command-line export_area  2. Page area  3. Drawing area
+        switch (export_area_type) {
+            case ExportAreaType::Unset:
+                std::cerr << "ExportAreaType::not_set should be handled before" << std::endl;
+                return 1;
+            case ExportAreaType::Page: {
+                // Export area page (explicit or if no object is given).
+                Geom::Point origin(doc->getRoot()->x.computed, doc->getRoot()->y.computed);
+                area = Geom::Rect(origin, origin + doc->getDimensions());
+                break;
+            }
+            case ExportAreaType::Area: {
+                // Export area command-line
+
+                /* Try to parse area (given in SVG pixels) */
+                gdouble x0, y0, x1, y1;
+                if (sscanf(export_area.c_str(), "%lg:%lg:%lg:%lg", &x0, &y0, &x1, &y1) != 4) {
+                    g_warning("Cannot parse export area '%s'; use 'x0:y0:x1:y1'. Nothing exported.",
+                              export_area.c_str());
+                    return 1; // If it fails once, it will fail for all objects.
+                }
+                area = Geom::Rect(Geom::Interval(x0, x1), Geom::Interval(y0, y1));
+                break;
+            }
+            case ExportAreaType::Drawing: {
+                // Export area drawing (explicit or if object is given).
+                Geom::OptRect areaMaybe = static_cast<SPItem *>(object)->documentVisualBounds();
+                if (areaMaybe) {
+                    area = *areaMaybe;
+                } else {
+                    std::cerr << "InkFileExport::do_export_png: "
+                              << "Unable to determine a valid bounding box. Skipping." << std::endl;
+                    continue;
+                }
+                break;
+            }
+        }
+
+        if (export_area_snap) {
+            area = area.roundOutwards();
+        }
+        // End finding area.
+        do_export_png_now(doc, filename_out, area, dpi, items);
+
+    } // End loop over objects.
+    prefs->setBool("/options/dithering/value", old_dither);
+    return 0;
+}
+
+void
+InkFileExportCmd::do_export_png_now(SPDocument *doc, std::string const &filename_out, Geom::Rect area, double dpi_in, const std::vector<SPItem *> &items)
+{
+    // -------------------------- DPI -------------------------------
+
+    double dpi = dpi_in;
+
+    if (export_dpi != 0.0 && dpi == 0.0) {
+        dpi = export_dpi;
+        if ((dpi < 0.1) || (dpi > 10000.0)) {
+            std::cerr << "InkFileExport::do_export_png: "
+                      << "DPI value " << export_dpi
+                      << " out of range [0.1 - 10000.0]. Skipping.";
+            return;
+        }
+    }
+
+    // default dpi
+    if (dpi == 0.0) {
+        dpi = Inkscape::Util::Quantity::convert(1, "in", "px");
+    }
+
+        // -------------------------- Width and Height ---------------------------------
+
+        unsigned long int width = 0;
+        unsigned long int height = 0;
+        double xdpi = dpi;
+        double ydpi = dpi;
+
+        if (export_height != 0) {
+            height = export_height;
+            if ((height < 1) || (height > PNG_UINT_31_MAX)) {
+                std::cerr << "InkFileExport::do_export_png: "
+                          << "Export height " << height << " out of range (1 to " << PNG_UINT_31_MAX << ")" << std::endl;
+                return;
+            }
+            ydpi = Inkscape::Util::Quantity::convert(height, "in", "px") / area.height();
+            xdpi = ydpi;
+            dpi = ydpi;
+        }
+
+        if (export_width != 0) {
+            width = export_width;
+            if ((width < 1) || (width > PNG_UINT_31_MAX)) {
+                std::cerr << "InkFileExport::do_export_png: "
+                          << "Export width " << width << " out of range (1 to " << PNG_UINT_31_MAX << ")." << std::endl;
+                return;
+            }
+            xdpi = Inkscape::Util::Quantity::convert(width, "in", "px") / area.width();
+            ydpi = export_height ? ydpi : xdpi;
+            dpi = xdpi;
+        }
+
+        if (width == 0) {
+            width = (unsigned long int) (Inkscape::Util::Quantity::convert(area.width(), "px", "in") * dpi + 0.5);
+        }
+
+        if (height == 0) {
+            height = (unsigned long int) (Inkscape::Util::Quantity::convert(area.height(), "px", "in") * dpi + 0.5);
+        }
+
+        if ((width < 1) || (height < 1) || (width > PNG_UINT_31_MAX) || (height > PNG_UINT_31_MAX)) {
+            std::cerr << "InkFileExport::do_export_png: Dimensions " << width << "x" << height << " are out of range (1 to " << PNG_UINT_31_MAX << ")." << std::endl;
+            return;
+        }
+
+        // -------------------------- Bit Depth and Color Type --------------------
+
+        int bit_depth = 8; // default of sp_export_png_file function
+        int color_type = PNG_COLOR_TYPE_RGB_ALPHA; // default of sp_export_png_file function
+
+        if (!export_png_color_mode.empty()) {
+            // data as in ui/dialog/export.cpp:
+            const std::map<std::string, std::pair<int, int>> color_modes = {
+                {"Gray_1", {PNG_COLOR_TYPE_GRAY, 1}},
+                {"Gray_2", {PNG_COLOR_TYPE_GRAY, 2}},
+                {"Gray_4", {PNG_COLOR_TYPE_GRAY, 4}},
+                {"Gray_8", {PNG_COLOR_TYPE_GRAY, 8}},
+                {"Gray_16", {PNG_COLOR_TYPE_GRAY, 16}},
+                {"RGB_8", {PNG_COLOR_TYPE_RGB, 8}},
+                {"RGB_16", {PNG_COLOR_TYPE_RGB, 16}},
+                {"GrayAlpha_8", {PNG_COLOR_TYPE_GRAY_ALPHA, 8}},
+                {"GrayAlpha_16", {PNG_COLOR_TYPE_GRAY_ALPHA, 16}},
+                {"RGBA_8", {PNG_COLOR_TYPE_RGB_ALPHA, 8}},
+                {"RGBA_16", {PNG_COLOR_TYPE_RGB_ALPHA, 16}},
+            };
+            auto it = color_modes.find(export_png_color_mode);
+            if (it == color_modes.end()) {
+                std::cerr << "InkFileExport::do_export_png: "
+                          << "Color mode " << export_png_color_mode.raw() << " is invalid. It must be one of Gray_1/Gray_2/Gray_4/Gray_8/Gray_16/RGB_8/RGB_16/GrayAlpha_8/GrayAlpha_16/RGBA_8/RGBA_16." << std::endl;
+                return;
+            } else {
+                std::tie(color_type, bit_depth) = it->second;
+            }
+        }
+
+        guint32 bgcolor = get_bgcolor(doc);
+        // ----------------------  Generate the PNG -------------------------------
+#ifdef DEBUG
+        std::cerr << "Background RRGGBBAA: " << std::hex << bgcolor << std::dec << std::endl;
+        std::cerr << "Area "
+                  << area[Geom::X][0] << ":" << area[Geom::Y][0] << ":"
+                  << area[Geom::X][1] << ":" << area[Geom::Y][1] << " exported to "
+                  << width << " x " << height << " pixels (" << dpi << " dpi)" << std::endl;
+#endif
+
+        if( sp_export_png_file(doc, filename_out.c_str(), area, width, height, xdpi, ydpi,
+                               bgcolor, nullptr, nullptr, true, export_id_only ? items : std::vector<SPItem*>(),
+                               false, color_type, bit_depth) == 1 ) {
+        } else {
+            std::cerr << "InkFileExport::do_export_png: Failed to export to " << filename_out << std::endl;
+        }
+}
+
+
+/**
+ *  Perform a PDF/PS/EPS export
+ *
+ *  \param doc Document to export.
+ *  \param filename File to write to.
+ *  \param mime MIME type to export as.
+ */
+int
+InkFileExportCmd::do_export_ps_pdf(SPDocument* doc, std::string const &filename_in, std::string const & mime_type)
+{
+    // Check if we support mime type.
+    Inkscape::Extension::DB::OutputList o;
+    Inkscape::Extension::db.get_output_list(o);
+    Inkscape::Extension::DB::OutputList::const_iterator i = o.begin();
+    while (i != o.end() && strcmp( (*i)->get_mimetype(), mime_type.c_str() ) != 0) {
+        ++i;
+    }
+
+    if (i == o.end()) {
+        std::cerr << "InkFileExportCmd::do_export_ps_pdf: Could not find an extension to export to MIME type: " << mime_type << std::endl;
+        return 1;
+    }
+    return do_export_ps_pdf(doc, filename_in, mime_type, *dynamic_cast<Inkscape::Extension::Output *>(*i));
+}
+
+/**
+ *  Perform a PDF/PS/EPS export
+ *
+ *  \param doc Document to export.
+ *  \param filename File to write to.
+ *  \param mime MIME type to export as.
+ *  \param Extension used for exporting
+ */
+int InkFileExportCmd::do_export_ps_pdf(SPDocument *doc, std::string const &filename_in, std::string const & mime_type,
+                                       Inkscape::Extension::Output &extension)
+{
+    // check if the passed extension conforms to the mime type.
+    assert(std::string(extension.get_mimetype()) == mime_type);
+    // Start with options that are once per document.
+
+    // Set export options.
+    if (export_text_to_path) {
+        extension.set_param_optiongroup("textToPath", "paths");
+    } else if (export_latex) {
+        extension.set_param_optiongroup("textToPath", "LaTeX");
+    } else {
+        extension.set_param_optiongroup("textToPath", "embed");
+    }
+
+    if (export_ignore_filters) {
+        extension.set_param_bool("blurToBitmap", false);
+    } else {
+        extension.set_param_bool("blurToBitmap", true);
+
+        gdouble dpi = 96.0;
+        if (export_dpi) {
+            dpi = export_dpi;
+            if ((dpi < 1) || (dpi > 10000.0)) {
+                g_warning("DPI value %lf out of range [1 - 10000]. Using 96 dpi instead.", export_dpi);
+                dpi = 96;
+            }
+        }
+
+        extension.set_param_int("resolution", (int)dpi);
+    }
+
+    // handle --export-pdf-version
+    if (mime_type == "application/pdf") {
+        bool set_export_pdf_version_fail = true;
+        const gchar *pdfver_param_name = "PDFversion";
+        if (!export_pdf_level.empty()) {
+            // combine "PDF " and the given command line
+            std::string version_gui_string = std::string("PDF-") + export_pdf_level.raw();
+            try {
+                // first, check if the given pdf version is selectable in the ComboBox
+                if (extension.get_param_optiongroup_contains("PDFversion", version_gui_string.c_str())) {
+                    extension.set_param_optiongroup(pdfver_param_name, version_gui_string.c_str());
+                    set_export_pdf_version_fail = false;
+                } else {
+                    g_warning("Desired PDF export version \"%s\" not supported! Hint: input one of the versions found in the pdf export dialog e.g. \"1.4\".",
+                              export_pdf_level.c_str());
+                }
+            } catch (...) {
+                // can be thrown along the way:
+                // throw Extension::param_not_exist();
+                // throw Extension::param_not_enum_param();
+                g_warning("Parameter or Enum \"%s\" might not exist", pdfver_param_name);
+            }
+        }
+
+        // set default pdf export version to 1.4, also if something went wrong
+        if(set_export_pdf_version_fail) {
+            extension.set_param_optiongroup(pdfver_param_name, "PDF-1.4");
+        }
+    }
+
+    if (mime_type == "image/x-postscript" || mime_type == "image/x-e-postscript") {
+        if ( export_ps_level < 2 || export_ps_level > 3 ) {
+            g_warning("Only supported PostScript levels are 2 and 3."
+                      " Defaulting to 2.");
+            export_ps_level = 2;
+        }
+
+        extension.set_param_optiongroup("PSlevel", (export_ps_level == 3) ? "PS3" : "PS2");
+    }
+
+    return do_export_vector(doc, filename_in, extension);
+}
+
+/**
+ *  Export a document using an export extension
+ *
+ *  \param doc Document to export.
+ *  \param filename to export to.
+ *  \param output extension used for export
+ */
+int InkFileExportCmd::do_export_extension(SPDocument *doc, std::string const &filename_in,
+                                          Inkscape::Extension::Output *extension)
+{
+    std::string filename_out = get_filename_out(filename_in);
+    if (extension) {
+        extension->set_state(Inkscape::Extension::Extension::STATE_LOADED);
+        try {
+            extension->set_gui(false);
+            extension->save(doc, filename_out.c_str());
+        } catch (Inkscape::Extension::Output::save_failed const &) {
+
+            std::cerr << __PRETTY_FUNCTION__ << ": Failed to save " << extension->get_id()
+                      << " to: " << filename_out << std::endl;
+            return 1;
+        }
+    }
+    return 0;
+}
+
+std::string export_area_type_string(ExportAreaType type)
+{
+    switch (type) {
+        case ExportAreaType::Area:
+            return "--export-area";
+        case ExportAreaType::Page:
+            return "--export-area-page";
+        case ExportAreaType::Drawing:
+            return "--export-area-drawing";
+        default:
+            return "default";
+    }
+}
+
+void InkFileExportCmd::set_export_area_type(ExportAreaType type)
+{
+    if ((export_area_type != ExportAreaType::Unset) && (export_area_type != type)) {
+        std::cerr << "Warning: multiple export area types have been set, overriding "
+                  << export_area_type_string(export_area_type) << " with " << export_area_type_string(type)
+                  << std::endl;
+    }
+    export_area_type = type;
+}
+
+void InkFileExportCmd::set_export_area(const Glib::ustring &area)
+{
+    export_area = area;
+    set_export_area_type(ExportAreaType::Area);
+}
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/io/file-export-cmd.h b/src/io/file-export-cmd.h
new file mode 100644
index 0000000..3b34a2a
--- /dev/null
+++ b/src/io/file-export-cmd.h
@@ -0,0 +1,103 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * File export from the command line. This code use to be in main.cpp. It should be
+ * replaced by shared code (Gio::Actions?) for export from the file dialog.
+ *
+ * Copyright (C) 2018 Tavmjong Bah
+ *
+ * The contents of this file may be used under the GNU General Public License Version 2 or later.
+ *
+ */
+
+#ifndef INK_FILE_EXPORT_CMD_H
+#define INK_FILE_EXPORT_CMD_H
+
+#include <iostream>
+#include <glibmm.h>
+#include "2geom/rect.h"
+
+class SPDocument;
+class SPItem;
+namespace Inkscape {
+namespace Extension {
+class Output;
+}
+} // namespace Inkscape
+
+enum class ExportAreaType
+{
+    Unset,
+    Drawing,
+    Page,
+    Area,
+};
+
+class InkFileExportCmd {
+
+public:
+    InkFileExportCmd();
+
+    void do_export(SPDocument* doc, std::string filename_in="");
+
+private:
+    ExportAreaType export_area_type{ExportAreaType::Unset};
+    Glib::ustring export_area{};
+    guint32 get_bgcolor(SPDocument *doc);
+    std::string get_filename_out(std::string filename_in = "", std::string object_id = "");
+    int do_export_svg(SPDocument *doc, std::string const &filename_in);
+    int do_export_vector(SPDocument *doc, std::string const &filename_in, Inkscape::Extension::Output &extension);
+    int do_export_png(SPDocument *doc, std::string const &filename_in);
+    int do_export_ps_pdf(SPDocument *doc, std::string const &filename_in, std::string const &mime_type);
+    int do_export_ps_pdf(SPDocument *doc, std::string const &filename_in, std::string const &mime_type,
+                         Inkscape::Extension::Output &extension);
+    int do_export_extension(SPDocument *doc, std::string const &filename_in, Inkscape::Extension::Output *extension);
+    Glib::ustring export_type_current;
+
+    void do_export_png_now(SPDocument *doc, std::string const &filename_out, Geom::Rect area, double dpi_in, const std::vector<SPItem *> &items);
+public:
+    // Should be private, but this is just temporary code (I hope!).
+
+    // One-to-one correspondence with command line options
+    std::string   export_filename; // Only if one file is processed!
+
+    Glib::ustring export_type;
+    Glib::ustring export_extension;
+    bool          export_overwrite;
+
+    int           export_margin;
+    bool          export_area_snap;
+    int           export_width;
+    int           export_height;
+
+    Glib::ustring export_page;
+
+    double        export_dpi;
+    bool          export_ignore_filters;
+    bool          export_text_to_path;
+    int           export_ps_level;
+    Glib::ustring export_pdf_level;
+    bool          export_latex;
+    Glib::ustring export_id;
+    bool          export_id_only;
+    bool          export_use_hints;
+    Glib::ustring export_background;
+    double        export_background_opacity;
+    Glib::ustring export_png_color_mode;
+    bool          export_plain_svg;
+    bool          export_png_use_dithering;
+    void set_export_area(const Glib::ustring &area);
+    void set_export_area_type(ExportAreaType type);
+};
+
+#endif // INK_FILE_EXPORT_CMD_H
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/io/file.cpp b/src/io/file.cpp
new file mode 100644
index 0000000..4c509dc
--- /dev/null
+++ b/src/io/file.cpp
@@ -0,0 +1,192 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * File operations (independent of GUI)
+ *
+ * Copyright (C) 2018, 2019 Tavmjong Bah
+ *
+ * The contents of this file may be used under the GNU General Public License Version 2 or later.
+ *
+ */
+
+#include "io/file.h"
+
+#include <iostream>
+#include <unistd.h>
+#include <giomm.h>
+
+#include "document.h"
+#include "document-undo.h"
+
+#include "extension/system.h"     // Extension::open()
+#include "extension/extension.h"
+#include "extension/db.h"
+#include "extension/output.h"
+#include "extension/input.h"
+
+#include "object/sp-root.h"
+
+#include "xml/repr.h"
+
+
+/**
+ * Create a blank document, remove any template data.
+ * Input: Empty string or template file name.
+ */
+SPDocument*
+ink_file_new(const std::string &Template)
+{
+    SPDocument *doc = SPDocument::createNewDoc ((Template.empty() ? nullptr : Template.c_str()), true, true );
+
+    if (doc) {
+        // Remove all the template info from xml tree
+        Inkscape::XML::Node *myRoot = doc->getReprRoot();
+        Inkscape::XML::Node *nodeToRemove;
+
+        nodeToRemove = sp_repr_lookup_name(myRoot, "inkscape:templateinfo");
+        if (nodeToRemove != nullptr) {
+            Inkscape::DocumentUndo::ScopedInsensitive no_undo(doc);
+            sp_repr_unparent(nodeToRemove);
+            delete nodeToRemove;
+        }
+        nodeToRemove = sp_repr_lookup_name(myRoot, "inkscape:_templateinfo"); // backwards-compatibility
+        if (nodeToRemove != nullptr) {
+            Inkscape::DocumentUndo::ScopedInsensitive no_undo(doc);
+            sp_repr_unparent(nodeToRemove);
+            delete nodeToRemove;
+        }
+    } else {
+        std::cerr << "ink_file_new: Did not create new document!" << std::endl;
+    }
+
+    return doc;
+}
+
+/**
+ * Open a document from memory.
+ */
+SPDocument*
+ink_file_open(const Glib::ustring& data)
+{
+    SPDocument *doc = SPDocument::createNewDocFromMem (data.c_str(), data.length(), true);
+
+    if (doc == nullptr) {
+        std::cerr << "ink_file_open: cannot open file in memory (pipe?)" << std::endl;
+    } else {
+
+        // This is the only place original values should be set.
+        SPRoot *root = doc->getRoot();
+        root->original.inkscape = root->version.inkscape;
+        root->original.svg      = root->version.svg;
+    }
+
+    return doc;
+}
+
+/**
+ * Open a document.
+ */
+SPDocument*
+ink_file_open(const Glib::RefPtr<Gio::File>& file, bool *cancelled_param)
+{
+    bool cancelled = false;
+
+    SPDocument *doc = nullptr;
+
+    std::string path = file->get_path();
+
+    // TODO: It's useless to catch these exceptions here (and below) unless we do something with them.
+    //       If we can't properly handle them (e.g. by showing a user-visible message) don't catch them!
+    try {
+        doc = Inkscape::Extension::open(nullptr, path.c_str());
+    } catch (Inkscape::Extension::Input::no_extension_found &e) {
+        doc = nullptr;
+    } catch (Inkscape::Extension::Input::open_failed &e) {
+        doc = nullptr;
+    } catch (Inkscape::Extension::Input::open_cancelled &e) {
+        cancelled = true;
+        doc = nullptr;
+    }
+
+    // Try to open explicitly as SVG.
+    // TODO: Why is this necessary? Shouldn't this be handled by the first call already?
+    if (doc == nullptr && !cancelled) {
+        try {
+            doc = Inkscape::Extension::open(Inkscape::Extension::db.get(SP_MODULE_KEY_INPUT_SVG), path.c_str());
+        } catch (Inkscape::Extension::Input::no_extension_found &e) {
+            doc = nullptr;
+        } catch (Inkscape::Extension::Input::open_failed &e) {
+            doc = nullptr;
+        } catch (Inkscape::Extension::Input::open_cancelled &e) {
+            cancelled = true;
+            doc = nullptr;
+        }
+    }
+
+    if (doc != nullptr) {
+        // This is the only place original values should be set.
+        SPRoot *root = doc->getRoot();
+        root->original.inkscape = root->version.inkscape;
+        root->original.svg      = root->version.svg;
+    } else if (!cancelled) {
+        std::cerr << "ink_file_open: '" << path << "' cannot be opened!" << std::endl;
+    }
+
+    if (cancelled_param) {
+        *cancelled_param = cancelled;
+    }
+    return doc;
+}
+
+namespace Inkscape {
+namespace IO {
+
+/**
+ * Create a temporary filename, which is closed and deleted when deconstructed.
+ */
+TempFilename::TempFilename(const std::string &pattern)
+    : _filename("")
+    , _tempfd(0)
+{
+    try {
+        _tempfd = Glib::file_open_tmp(_filename, pattern.c_str());
+    } catch (...) {
+        /// \todo Popup dialog here
+        return;
+    }
+}
+  
+TempFilename::~TempFilename()
+{
+    close(_tempfd);
+    unlink(_filename.c_str());
+}
+
+/**
+ * Takes an absolute file path and returns a second file at the same
+ * directory location, if and only if the filename exists and is a file.
+ *
+ * Returns the empty string if the new file is not found.
+ */
+Glib::ustring find_original_file(Glib::ustring filepath, Glib::ustring name)
+{
+    auto path = Glib::path_get_dirname(filepath);
+    auto filename = Glib::build_filename(path, name);
+
+    if (Glib::file_test(filename, Glib::FILE_TEST_IS_REGULAR)) {
+        return filename;
+    }
+    return ""; 
+}
+
+}}
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/io/file.h b/src/io/file.h
new file mode 100644
index 0000000..82aa747
--- /dev/null
+++ b/src/io/file.h
@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * File operations (independent of GUI)
+ *
+ * Copyright (C) 2018 Tavmjong Bah
+ *
+ * The contents of this file may be used under the GNU General Public License Version 2 or later.
+ *
+ */
+
+#ifndef INK_FILE_IO_H
+#define INK_FILE_IO_H
+
+#include <string>
+
+namespace Gio {
+class File;
+}
+
+namespace Glib {
+class ustring;
+
+template <class T>
+class RefPtr;
+}
+
+class SPDocument;
+
+SPDocument* ink_file_new(const std::string &Template = "");
+SPDocument* ink_file_open(const Glib::ustring &data);
+SPDocument* ink_file_open(const Glib::RefPtr<Gio::File>& file, bool *cancelled = nullptr);
+
+namespace Inkscape {
+namespace IO {
+
+class TempFilename {
+    public:
+        TempFilename(const std::string &pattern);
+        ~TempFilename();
+
+        std::string get_filename() const { return _filename; }
+    private:
+        std::string _filename;
+        int _tempfd;
+};
+
+Glib::ustring find_original_file(Glib::ustring filepath, Glib::ustring name);
+
+}}
+
+// To do:
+// ink_file_save()
+// ink_file_export()
+// ink_file_import()
+
+
+
+#endif // INK_FILE_IO_H
diff --git a/src/io/fix-broken-links.cpp b/src/io/fix-broken-links.cpp
new file mode 100644
index 0000000..0abf837
--- /dev/null
+++ b/src/io/fix-broken-links.cpp
@@ -0,0 +1,416 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * tracks external resources such as image and css files.
+ *
+ * Copyright 2011  Jon A. Cruz  <jon@joncruz.org>
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <string>
+#include <vector>
+#include <set>
+#include <algorithm>
+
+#include <gtkmm/recentmanager.h>
+#include <glibmm/i18n.h>
+#include <glibmm/miscutils.h>
+#include <glibmm/fileutils.h>
+#include <glibmm/uriutils.h>
+#include <glibmm/convert.h>
+
+#include "fix-broken-links.h"
+
+#include "document.h"
+#include "document-undo.h"
+
+#include "object/sp-object.h"
+
+#include "ui/icon-names.h"
+
+#include "xml/node.h"
+#include "xml/href-attribute-helper.h"
+
+namespace Inkscape {
+
+static std::vector<std::string> splitPath( std::string const &path )
+{
+    std::vector<std::string> parts;
+
+    std::string prior;
+    std::string tmp = path;
+    while ( !tmp.empty() && (tmp != prior) ) {
+        prior = tmp;
+
+        parts.push_back( Glib::path_get_basename(tmp) );
+        tmp = Glib::path_get_dirname(tmp);
+    }
+    if ( !parts.empty() ) {
+        std::reverse(parts.begin(), parts.end());
+        if ( (parts[0] == ".") && (path[0] != '.') ) {
+            parts.erase(parts.begin());
+        }
+    }
+
+    return parts;
+}
+
+std::string convertPathToRelative( std::string const &path, std::string const &docbase )
+{
+    std::string result = path;
+
+    if ( !path.empty() && Glib::path_is_absolute(path) ) {
+        // Whack the parts into pieces
+
+        std::vector<std::string> parts = splitPath(path);
+        std::vector<std::string> baseParts = splitPath(docbase);
+
+        // TODO debug g_message("+++++++++++++++++++++++++");
+        for ( std::vector<std::string>::iterator it = parts.begin(); it != parts.end(); ++it ) {
+            // TODO debug g_message("    [%s]", it->c_str());
+        }
+        // TODO debug g_message(" - - - - - - - - - - - - - - - ");
+        for ( std::vector<std::string>::iterator it = baseParts.begin(); it != baseParts.end(); ++it ) {
+            // TODO debug g_message("    [%s]", it->c_str());
+        }
+        // TODO debug g_message("+++++++++++++++++++++++++");
+
+        if ( !parts.empty() && !baseParts.empty() && (parts[0] == baseParts[0]) ) {
+            // Both paths have the same root. We can proceed.
+            while ( !parts.empty() && !baseParts.empty() && (parts[0] == baseParts[0]) ) {
+                parts.erase( parts.begin() );
+                baseParts.erase( baseParts.begin() );
+            }
+
+            // TODO debug g_message("+++++++++++++++++++++++++");
+            for ( std::vector<std::string>::iterator it = parts.begin(); it != parts.end(); ++it ) {
+                // TODO debug g_message("    [%s]", it->c_str());
+            }
+            // TODO debug g_message(" - - - - - - - - - - - - - - - ");
+            for ( std::vector<std::string>::iterator it = baseParts.begin(); it != baseParts.end(); ++it ) {
+                // TODO debug g_message("    [%s]", it->c_str());
+            }
+            // TODO debug g_message("+++++++++++++++++++++++++");
+
+            if ( !parts.empty() ) {
+                result.clear();
+
+                for ( size_t i = 0; i < baseParts.size(); ++i ) {
+                    parts.insert(parts.begin(), "..");
+                }
+                result = Glib::build_filename( parts );
+                // TODO debug g_message("----> [%s]", result.c_str());
+            }
+        }
+    }
+
+    return result;
+}
+
+
+bool fixBrokenLinks(SPDocument *doc);
+    
+
+/**
+ * Walk all links in a document and create a listing of unique broken links.
+ *
+ * @return a list of all broken links.
+ */
+static std::vector<Glib::ustring> findBrokenLinks(SPDocument *doc);
+
+/**
+ * Resolve broken links as a whole and return a map for those that can be found.
+ *
+ * Note: this will allow for future enhancements including relinking to new locations
+ * with the most broken files found, etc.
+ *
+ * @return a map of found links.
+ */
+static std::map<Glib::ustring, Glib::ustring> locateLinks(Glib::ustring const & docbase, std::vector<Glib::ustring> const & brokenLinks);
+
+
+/**
+ * Try to parse href into a local filename using standard methods.
+ *
+ * @return true if successful.
+ */
+static bool extractFilepath(Glib::ustring const &href, std::string &filename);
+
+/**
+ * Try to parse href into a local filename using some non-standard methods.
+ * This means the href is likely invalid and should be rewritten.
+ *
+ * @return true if successful.
+ */
+static bool reconstructFilepath(Glib::ustring const &href, std::string &filename);
+
+static bool searchUpwards( std::string const &base, std::string const &subpath, std::string &dest );
+
+
+
+static bool extractFilepath(Glib::ustring const &href, std::string &filename)
+{                    
+    bool isFile = false;
+
+    filename.clear();
+
+    auto scheme = Glib::uri_parse_scheme(href.raw());
+    if ( !scheme.empty() ) {
+        // TODO debug g_message("Scheme is now [%s]", scheme.c_str());
+        if ( scheme == "file" ) {
+            // TODO debug g_message("--- is a file URI                 [%s]", href.c_str());
+
+            // throws Glib::ConvertError:
+            try {
+                filename = Glib::filename_from_uri(href);
+                isFile = true;
+            } catch(Glib::ConvertError e) {
+                g_warning("%s", e.what().c_str());
+            }
+        }
+    } else {
+        // No scheme. Assuming it is a file path (absolute or relative).
+        // throws Glib::ConvertError:
+        filename = Glib::filename_from_utf8(href);
+        isFile = true;
+    }
+
+    return isFile;
+}
+
+static bool reconstructFilepath(Glib::ustring const &href, std::string &filename)
+{                    
+    bool isFile = false;
+
+    filename.clear();
+
+    auto scheme = Glib::uri_parse_scheme(href.raw());
+    if ( !scheme.empty() ) {
+        if ( scheme == "file" ) {
+            // try to build a relative filename for URIs like "file:image.png"
+            // they're not standard conformant but not uncommon
+            Glib::ustring href_new = Glib::ustring(href, 5);
+            filename = Glib::filename_from_utf8(href_new);
+            isFile = true;
+        }
+    }
+    return isFile;
+}
+
+
+static std::vector<Glib::ustring> findBrokenLinks( SPDocument *doc )
+{
+    std::vector<Glib::ustring> result;
+    std::set<Glib::ustring> uniques;
+
+    if ( doc ) {
+        std::vector<SPObject *> images = doc->getResourceList("image");
+        for (auto image : images) {
+            Inkscape::XML::Node *ir = image->getRepr();
+
+            gchar const *href = Inkscape::getHrefAttribute(*ir).second;
+            if ( href &&  ( uniques.find(href) == uniques.end() ) ) {
+                std::string filename;
+                if (extractFilepath(href, filename)) {
+                    if (Glib::path_is_absolute(filename)) {
+                        if (!Glib::file_test(filename, Glib::FILE_TEST_EXISTS)) {
+                            result.emplace_back(href);
+                            uniques.insert(href);
+                        }
+                    } else {
+                        std::string combined = Glib::build_filename(doc->getDocumentBase(), filename);
+                        if ( !Glib::file_test(combined, Glib::FILE_TEST_EXISTS) ) {
+                            result.emplace_back(href);
+                            uniques.insert(href);
+                        }
+                    }
+                } else if (reconstructFilepath(href, filename)) {
+                    result.emplace_back(href);
+                    uniques.insert(href);
+                }
+            }
+        }        
+    }
+
+    return result;
+}
+
+
+static std::map<Glib::ustring, Glib::ustring> locateLinks(Glib::ustring const & docbase, std::vector<Glib::ustring> const & brokenLinks)
+{
+    std::map<Glib::ustring, Glib::ustring> result;
+
+
+    // Note: we use a vector because we want them to stay in order:
+    std::vector<std::string> priorLocations;
+
+    Glib::RefPtr<Gtk::RecentManager> recentMgr = Gtk::RecentManager::get_default();
+    std::vector< Glib::RefPtr<Gtk::RecentInfo> > recentItems = recentMgr->get_items();
+    for (auto & recentItem : recentItems) {
+        Glib::ustring uri = recentItem->get_uri();
+        auto scheme = Glib::uri_parse_scheme(uri.raw());
+        if ( scheme == "file" ) {
+            try {
+                std::string path = Glib::filename_from_uri(uri);
+                path = Glib::path_get_dirname(path);
+                if ( std::find(priorLocations.begin(), priorLocations.end(), path) == priorLocations.end() ) {
+                    // TODO debug g_message("               ==>[%s]", path.c_str());
+                    priorLocations.push_back(path);
+                }
+            } catch (Glib::ConvertError e) {
+                g_warning("%s", e.what().c_str());
+            }
+        }
+    }
+
+    // At the moment we expect this list to contain file:// references, or simple relative or absolute paths.
+    for (const auto & brokenLink : brokenLinks) {
+        // TODO debug g_message("========{%s}", it->c_str());
+
+        std::string filename;
+        if (extractFilepath(brokenLink, filename) || reconstructFilepath(brokenLink, filename)) {
+            auto const docbase_native = Glib::filename_from_utf8(docbase);
+
+            // We were able to get some path. Check it
+            std::string origPath = filename;
+
+            if (!Glib::path_is_absolute(filename)) {
+                filename = Glib::build_filename(docbase_native, filename);
+            }
+
+            bool exists = Glib::file_test(filename, Glib::FILE_TEST_EXISTS);
+
+            // search in parent folders
+            if (!exists) {
+                exists = searchUpwards(docbase_native, origPath, filename);
+            }
+
+            // Check if the MRU bases point us to it.
+            if ( !exists ) {
+                if ( !Glib::path_is_absolute(origPath) ) {
+                    for ( std::vector<std::string>::iterator it = priorLocations.begin(); !exists && (it != priorLocations.end()); ++it ) {
+                        exists = searchUpwards(*it, origPath, filename);
+                    }
+                }
+            }
+
+            if ( exists ) {
+                if (Glib::path_is_absolute(filename)) {
+                    filename = convertPathToRelative(filename, docbase_native);
+                }
+
+                bool isAbsolute = Glib::path_is_absolute(filename);
+                Glib::ustring replacement =
+                    isAbsolute ? Glib::filename_to_uri(filename) : Glib::filename_to_utf8(filename);
+                result[brokenLink] = replacement;
+            }
+        }
+    }
+
+    return result;
+}
+
+bool fixBrokenLinks(SPDocument *doc)
+{
+    bool changed = false;
+    if ( doc ) {
+        // TODO debug g_message("FIXUP FIXUP FIXUP FIXUP FIXUP FIXUP FIXUP FIXUP FIXUP FIXUP");
+        // TODO debug g_message("      base is [%s]", doc->getDocumentBase());
+
+        std::vector<Glib::ustring> brokenHrefs = findBrokenLinks(doc);
+        if ( !brokenHrefs.empty() ) {
+            // TODO debug g_message("    FOUND SOME LINKS %d", static_cast<int>(brokenHrefs.size()));
+            for ( std::vector<Glib::ustring>::iterator it = brokenHrefs.begin(); it != brokenHrefs.end(); ++it ) {
+                // TODO debug g_message("        [%s]", it->c_str());
+            }
+        }
+
+        Glib::ustring base;
+        if (doc->getDocumentBase()) {
+            base = doc->getDocumentBase();
+        }
+
+        std::map<Glib::ustring, Glib::ustring> mapping = locateLinks(base, brokenHrefs);
+        for ( std::map<Glib::ustring, Glib::ustring>::iterator it = mapping.begin(); it != mapping.end(); ++it )
+        {
+            // TODO debug g_message("     [%s] ==> {%s}", it->first.c_str(), it->second.c_str());
+        }
+
+        DocumentUndo::ScopedInsensitive _no_undo(doc);
+        
+        std::vector<SPObject *> images = doc->getResourceList("image");
+        for (auto image : images) {
+            Inkscape::XML::Node *ir = image->getRepr();
+
+            auto [href_key, href] = Inkscape::getHrefAttribute(*ir);
+            if ( href ) {
+                // TODO debug g_message("                  consider [%s]", href);
+                
+                if ( mapping.find(href) != mapping.end() ) {
+                    // TODO debug g_message("                     Found a replacement");
+
+                    ir->setAttributeOrRemoveIfEmpty(href_key, mapping[href]);
+                    if ( ir->attribute( "sodipodi:absref" ) ) {
+                        ir->removeAttribute("sodipodi:absref"); // Remove this attribute
+                    }
+
+                    SPObject *updated = doc->getObjectByRepr(ir);
+                    if (updated) {
+                        // force immediate update of dependent attributes
+                        updated->updateRepr();
+                    }
+
+                    changed = true;
+                }
+            }
+        }
+        if ( changed ) {
+            DocumentUndo::done( doc, _("Fixup broken links"), INKSCAPE_ICON("dialog-xml-editor"));
+        }
+    }
+
+    return changed;
+}
+
+static bool searchUpwards( std::string const &base, std::string const &subpath, std::string &dest )
+{
+    bool exists = false;
+    // TODO debug g_message("............");
+
+    std::vector<std::string> parts = splitPath(subpath);
+    std::vector<std::string> baseParts = splitPath(base);
+
+    while ( !exists && !baseParts.empty() ) {
+        std::vector<std::string> current;
+        current.insert(current.begin(), parts.begin(), parts.end());
+        // TODO debug g_message("         ---{%s}", Glib::build_filename( baseParts ).c_str());
+        while ( !exists && !current.empty() ) {
+            std::vector<std::string> combined;
+            combined.insert( combined.end(), baseParts.begin(), baseParts.end() );
+            combined.insert( combined.end(), current.begin(), current.end() );
+            std::string filepath = Glib::build_filename( combined );
+            exists = Glib::file_test(filepath, Glib::FILE_TEST_EXISTS);
+            // TODO debug g_message("            ...[%s] %s", filepath.c_str(), (exists ? "XXX" : ""));
+            if ( exists ) {
+                dest = filepath;
+            }
+            current.erase( current.begin() );
+        }
+        baseParts.pop_back();
+    }
+
+    return exists;
+}
+
+} // namespace Inkscape
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/io/fix-broken-links.h b/src/io/fix-broken-links.h
new file mode 100644
index 0000000..525f9bf
--- /dev/null
+++ b/src/io/fix-broken-links.h
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Manages external resources such as image and css files.
+ *
+ * Copyright 2011  Jon A. Cruz  <jon@joncruz.org>
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <string>
+
+class SPDocument;
+
+namespace Inkscape {
+
+std::string convertPathToRelative(std::string const &path, std::string const &docbase);
+bool fixBrokenLinks(SPDocument *doc);
+
+}
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/io/http.cpp b/src/io/http.cpp
new file mode 100644
index 0000000..6f28db7
--- /dev/null
+++ b/src/io/http.cpp
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * Inkscape::IO::HTTP - make internet requests using libsoup
+ *//*
+ * Authors: see git history
+ *
+ * Copyright (C) 2018 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+/*
+ * How to use:
+ *
+ *  #include "io/http.cpp"
+ *  void _async_test_call(Glib::ustring filename) {
+ *      g_warning("HTTP request saved to %s", filename.c_str());
+ *  }
+ *  uint timeout = 20 * 60 * 60; // 20 hours
+ *  Glib::ustring filename = Inkscape::IO::HTTP::get_file("https://media.inkscape.org/media/messages.xml", timeout, _async_test_call);
+ *
+ */
+
+#include <glib/gstdio.h>
+#include <libsoup/soup.h>
+#include <string>
+#include <ctime>
+
+#include "io/sys.h"
+#include "io/http.h"
+#include "io/resource.h"
+
+typedef std::function<void(Glib::ustring)> callback;
+
+namespace Resource = Inkscape::IO::Resource;
+
+namespace Inkscape {
+namespace IO {
+namespace HTTP {
+
+void _save_data_as_file(Glib::ustring filename, const char *result) {
+    FILE *fileout = Inkscape::IO::fopen_utf8name(filename.c_str(), "wb");
+    if (!fileout) {
+        g_warning("HTTP Cache: Can't open %s for write.", filename.c_str());
+        return;
+    }
+
+    fputs(result, fileout);
+    fflush(fileout);
+    if (ferror(fileout)) {
+        g_warning("HTTP Cache: Error writing data to %s.", filename.c_str());
+    }
+
+    fclose(fileout);
+}
+
+void _get_file_callback(SoupSession *session, SoupMessage *msg, gpointer user_data) {
+    auto data = static_cast<std::pair<callback, Glib::ustring>*>(user_data);
+    data->first(data->second);
+    delete data;
+}
+
+/*
+ * Downloads a file, caches it in the local filesystem and then returns the
+ * new filename of the cached file.
+ *
+ * Returns: filename where the file has been (blocking) or will be (async) stored.
+ *
+ * uri - The uri of the desired resource, the filename comes from this uri
+ * timeout - Number of seconds to keep the cache, default is forever
+ * func - An optional function, if given the function becomes asynchronous
+ *        the returned filename will be where the file 'hopes' to be saved
+ *        and this function will be called when the http request is complete.
+ *
+ *  NOTE: If the cache file exists, then it's returned without any async request
+ *        your func will be called in a blocking way BEFORE this function returns.
+ *
+ */
+Glib::ustring get_file(Glib::ustring uri, unsigned int timeout, callback func) {
+
+    SoupURI *s_uri = soup_uri_new(uri.c_str());
+    std::string path = std::string(soup_uri_decode(soup_uri_get_path(s_uri)));
+    std::string filepart;
+
+    // Parse the url into a filename suitable for caching.
+    if(path.back() == '/') {
+        filepart = path.replace(path.begin(), path.end(), '/', '_');
+        filepart += ".url";
+    } else {
+        filepart = path.substr(path.rfind("/") + 1);
+    }
+
+    const char *ret = get_path(Resource::CACHE, Resource::NONE, filepart.c_str());
+    Glib::ustring filename = Glib::ustring(ret);
+
+    // We test first if the cache already exists
+    if(file_test(filename.c_str(), G_FILE_TEST_EXISTS) && timeout > 0) {
+        GStatBuf st;
+        if(g_stat(filename.c_str(), &st) != -1) {
+	    time_t changed = st.st_mtime;
+	    time_t now = time(nullptr);
+            // The cache hasn't timed out, so return the filename.
+	    if(now - changed < timeout) {
+                if(func) {
+                    // Non-async func callback return, may block.
+                    func(filename);
+                }
+                return filename;
+            }
+            g_debug("HTTP Cache is stale: %s", filename.c_str());
+        }
+    }
+
+    // Only then do we get the http request
+    SoupMessage *msg = soup_message_new_from_uri("GET", s_uri);
+    SoupSession *session = soup_session_new();
+
+#ifdef DEBUG_HTTP
+    SoupLogger *logger;
+    logger = soup_logger_new(SOUP_LOGGER_LOG_BODY, -1);
+    soup_session_add_feature(session, SOUP_SESSION_FEATURE (logger));
+    g_object_unref (logger);
+#endif
+
+    if(func) {
+        auto *user_data = new std::pair<callback, Glib::ustring>(func, filename);
+        soup_session_queue_message(session, msg, _get_file_callback, user_data);
+    } else {
+        guint status = soup_session_send_message (session, msg);
+        if(status == SOUP_STATUS_OK) {
+            g_debug("HTTP Cache saved to: %s", filename.c_str());
+            _save_data_as_file(filename, msg->response_body->data);
+        } else {
+            g_warning("Can't download %s", uri.c_str());
+        }
+    }
+    return filename;
+}
+
+
+}
+}
+}
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/io/http.h b/src/io/http.h
new file mode 100644
index 0000000..398d699
--- /dev/null
+++ b/src/io/http.h
@@ -0,0 +1,41 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * Inkscape::IO::HTTP - make internet requests using libsoup
+ *//*
+ * Authors: see git history
+ *
+ * Copyright (C) 2018 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef SEEN_INKSCAPE_IO_HTTP_H
+#define SEEN_INKSCAPE_IO_HTTP_H
+
+#include <functional>
+#include <glibmm/ustring.h>
+
+/**
+ * simple libsoup based resource API
+ */
+
+namespace Inkscape {
+namespace IO {
+namespace HTTP {
+
+    Glib::ustring get_file(Glib::ustring uri, unsigned int timeout=0, std::function<void(Glib::ustring)> func=nullptr);
+
+}
+}
+}
+
+#endif
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/io/resource.cpp b/src/io/resource.cpp
new file mode 100644
index 0000000..aa8af77
--- /dev/null
+++ b/src/io/resource.cpp
@@ -0,0 +1,559 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * Inkscape::IO::Resource - simple resource API
+ *//*
+ * Authors:
+ *   MenTaLguY <mental@rydia.net>
+ *   Martin Owens <doctormo@gmail.com>
+ *
+ * Copyright (C) 2018 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"  // only include where actually required!
+#endif
+
+#ifdef _WIN32
+#include <shlobj.h> // for SHGetSpecialFolderLocation
+#endif
+
+#include <glibmm/convert.h>
+#include <glibmm/i18n.h>
+#include <glibmm/miscutils.h>
+#include <glibmm/stringutils.h>
+#include <glibmm/fileutils.h>
+
+#include "path-prefix.h"
+#include "io/sys.h"
+#include "io/resource.h"
+#include "inkscape-application.h"
+#include "preferences.h"
+
+using Inkscape::IO::file_test;
+
+namespace Inkscape {
+
+namespace IO {
+
+namespace Resource {
+
+
+static void get_foldernames_from_path(std::vector<Glib::ustring> &folders, std::string const &path,
+                                      std::vector<const char *> const &exclusions = {});
+
+#define INKSCAPE_PROFILE_DIR "inkscape"
+
+gchar *_get_path(Domain domain, Type type, char const *filename)
+{
+    if (domain == USER || domain == SHARED) {
+        switch (type) {
+        case ATTRIBUTES:
+        case EXAMPLES:
+        case DOCS:
+        case SCREENS:
+        case TUTORIALS:
+            // Happens for example with `get_filename_string(SCREENS, ...)`
+            // but we don't want a user configurable about screen.
+            return nullptr;
+        }
+    }
+
+    char const *name = nullptr;
+    char const *sysdir = nullptr;
+    char const *envor = nullptr;
+
+    switch (domain) {
+        case CREATE: {
+            sysdir = "create";
+            switch (type) {
+                case PAINT: name = "paint"; break;
+                case PALETTES: name = "swatches"; break;
+                default: return nullptr;
+            }
+        } break;
+        case CACHE: {
+            g_assert(type == NONE);
+            return g_build_filename(g_get_user_cache_dir(), "inkscape", filename, nullptr);
+        } break;
+
+        case SYSTEM:
+            sysdir = "inkscape";
+        case SHARED:
+        case USER: {
+            switch (type) {
+                case ATTRIBUTES: name = "attributes"; break;
+                case DOCS: name = "doc"; break;
+                case EXAMPLES: name = "examples"; break;
+                case EXTENSIONS: name = "extensions"; envor = "INKSCAPE_EXTENSIONS_DIR"; break;
+                case FILTERS: name = "filters"; break;
+                case FONTS: name = "fonts"; break;
+                case FONTCOLLECTIONS: name = "fontcollections"; break;
+                case ICONS: name = "icons"; break;
+                case KEYS: name = "keys"; break;
+                case MARKERS: name = "markers"; break;
+                case PAINT: name = "paint"; break;
+                case PALETTES: name = "palettes"; break;
+                case SCREENS: name = "screens"; break;
+                case SYMBOLS: name = "symbols"; break;
+                case TEMPLATES: name = "templates"; break;
+                case THEMES: name = "themes"; break;
+                case TUTORIALS: name = "tutorials"; break;
+                case UIS: name = "ui"; break;
+                case PIXMAPS: name = "pixmaps"; break;
+                default: g_assert_not_reached();
+                         return nullptr;
+            }
+        } break;
+    }
+    // Look for an over-ride in the local environment
+    if (envor && domain == USER) {
+        std::string env_dir = Glib::getenv(envor);
+        if (!env_dir.empty()) {
+            return g_build_filename(env_dir.c_str(), filename, nullptr);
+        }
+    }
+
+    if (!name) {
+        return nullptr;
+    }
+
+    if (sysdir) {
+        return g_build_filename(get_inkscape_datadir(), sysdir, name, filename, nullptr);
+    } else if (domain == SHARED) {
+        if (shared_path().empty()) {
+            return nullptr;
+        }
+        return g_build_filename(shared_path().c_str(), name, filename, nullptr);
+    } else {
+        if (profile_path().empty()) {
+            return nullptr;
+        }
+        return g_build_filename(profile_path().c_str(), name, filename, nullptr);
+    }
+}
+
+
+
+Util::ptr_shared get_path(Domain domain, Type type, char const *filename)
+{
+    char *path = _get_path(domain, type, filename);
+    if (!path) {
+        return Util::ptr_shared();
+    }
+    Util::ptr_shared result=Util::share_string(path);
+    g_free(path);
+    return result;
+}
+Glib::ustring get_path_ustring(Domain domain, Type type, char const *filename)
+{
+    Glib::ustring result;
+    char *path = _get_path(domain, type, filename);
+    if(path) {
+      result = Glib::ustring(path);
+      g_free(path);
+    }
+    return result;
+}
+std::string get_path_string(Domain domain, Type type, char const *filename)
+{
+    std::string result;
+    char *path = _get_path(domain, type, filename);
+    if (path) {
+        result = path;
+        g_free(path);
+    }
+    return result;
+}
+
+/*
+ * Same as get_path, but checks for file's existence and falls back
+ * from USER to SYSTEM modes.
+ *
+ *  type      - The type of file to get, such as extension, template, ui etc
+ *  filename  - The filename to get, i.e. preferences.xml
+ *  localized - Prefer a localized version of the file, i.e. default.de.svg instead of default.svg.
+ *              (will use gettext to determine the preferred language of the user)
+ *  silent    - do not warn if file doesn't exist
+ * 
+ */
+Glib::ustring get_filename(Type type, char const *filename, bool localized, bool silent)
+{
+    return get_filename_string(type, filename, localized, silent);
+}
+
+std::string get_filename_string(Type type, char const *filename, bool localized, bool silent)
+{
+    std::string result;
+
+    char *user_filename = nullptr;
+    char *shared_filename = nullptr;
+    char *sys_filename = nullptr;
+    char *user_filename_localized = nullptr;
+    char *sys_filename_localized = nullptr;
+
+    // TRANSLATORS: 'en' is an ISO 639-1 language code.
+    // Replace with language code for your language, i.e. the name of your .po file
+    localized = localized && strcmp(_("en"), "en");
+
+    if (localized) {
+        std::string localized_filename = filename;
+        localized_filename.insert(localized_filename.rfind('.'), ".");
+        localized_filename.insert(localized_filename.rfind('.'), _("en"));
+
+        user_filename_localized = _get_path(USER, type, localized_filename.c_str());
+        sys_filename_localized = _get_path(SYSTEM, type, localized_filename.c_str());
+    }
+    user_filename = _get_path(USER, type, filename);
+    shared_filename = _get_path(SHARED, type, filename);
+    sys_filename = _get_path(SYSTEM, type, filename);
+
+    // impose the following load order:
+    //   USER (localized) > USER > SYSTEM (localized) > SYSTEM
+    if (localized && file_test(user_filename_localized, G_FILE_TEST_EXISTS)) {
+        result = user_filename_localized;
+        g_info("Found localized version of resource file '%s' in profile directory:\n\t%s", filename, result.c_str());
+    } else if (file_test(user_filename, G_FILE_TEST_EXISTS)) {
+        result = user_filename;
+        g_info("Found resource file '%s' in profile directory:\n\t%s", filename, result.c_str());
+    } else if (file_test(shared_filename, G_FILE_TEST_EXISTS)) {
+        result = shared_filename;
+        g_info("Found resource file '%s' in profile directory:\n\t%s", filename, result.c_str());
+    } else if (localized && file_test(sys_filename_localized, G_FILE_TEST_EXISTS)) {
+        result = sys_filename_localized;
+        g_info("Found localized version of resource file '%s' in system directory:\n\t%s", filename, result.c_str());
+    } else if (file_test(sys_filename, G_FILE_TEST_EXISTS)) {
+        result = sys_filename;
+        g_info("Found resource file '%s' in system directory:\n\t%s", filename, result.c_str());
+    } else if (!silent) {
+        if (localized) {
+            g_warning("Failed to find resource file '%s'. Looked in:\n\t%s\n\t%s\n\t%s\n\t%s\n\t%s",
+                      filename, user_filename_localized, user_filename, shared_filename, sys_filename_localized, sys_filename);
+        } else {
+            g_warning("Failed to find resource file '%s'. Looked in:\n\t%s\n\t%s\n\t%s",
+                      filename, user_filename, shared_filename, sys_filename);
+        }
+    }
+
+    g_free(user_filename);
+    g_free(shared_filename);
+    g_free(sys_filename);
+    g_free(user_filename_localized);
+    g_free(sys_filename_localized);
+
+    return result;
+}
+
+/*
+ * Similar to get_filename, but takes a path (or filename) for relative resolution
+ *
+ *  path - A directory or filename that is considered local to the path resolution.
+ *  filename - The filename that we are looking for.
+ */
+Glib::ustring get_filename(Glib::ustring path, Glib::ustring filename)
+{
+    return get_filename(Glib::filename_from_utf8(path), //
+                        Glib::filename_from_utf8(filename));
+}
+
+std::string get_filename(std::string const& path, std::string const& filename)
+{
+    // Test if it's a filename and get the parent directory instead
+    if (Glib::file_test(path, Glib::FILE_TEST_IS_REGULAR)) {
+        auto dirname = Glib::path_get_dirname(path);
+        g_assert(!Glib::file_test(dirname, Glib::FILE_TEST_IS_REGULAR)); // recursion sanity check
+        return get_filename(dirname, filename);
+    }
+    if (g_path_is_absolute(filename.c_str())) {
+        if (Glib::file_test(filename, Glib::FILE_TEST_EXISTS)) {
+            return filename;
+        }
+    } else {
+        auto ret = Glib::build_filename(path, filename);
+        if (Glib::file_test(ret, Glib::FILE_TEST_EXISTS)) {
+            return ret;
+        }
+    }
+    return {};
+}
+
+/*
+ * Gets all the files in a given type, for all domain types.
+ *
+ *  domain - Optional domain (overload), will check return domains if not.
+ *  type - The type of files, e.g. TEMPLATES
+ *  extensions - A list of extensions to return, e.g. xml, svg
+ *  exclusions - A list of names to exclude e.g. default.xml
+ */
+std::vector<Glib::ustring> get_filenames(Type type, std::vector<const char *> const &extensions, std::vector<const char *> const &exclusions)
+{
+    std::vector<Glib::ustring> ret;
+    get_filenames_from_path(ret, get_path_string(USER, type), extensions, exclusions);
+    get_filenames_from_path(ret, get_path_string(SHARED, type), extensions, exclusions);
+    get_filenames_from_path(ret, get_path_string(SYSTEM, type), extensions, exclusions);
+    get_filenames_from_path(ret, get_path_string(CREATE, type), extensions, exclusions);
+    return ret;
+}
+
+std::vector<Glib::ustring> get_filenames(Domain domain, Type type, std::vector<const char *> const &extensions, std::vector<const char *> const &exclusions)
+{
+    std::vector<Glib::ustring> ret;
+    get_filenames_from_path(ret, get_path_string(domain, type), extensions, exclusions);
+    return ret;
+}
+std::vector<Glib::ustring> get_filenames(Glib::ustring path, std::vector<const char *> const &extensions, std::vector<const char *> const &exclusions)
+{
+    std::vector<Glib::ustring> ret;
+    get_filenames_from_path(ret, Glib::filename_from_utf8(path), extensions, exclusions);
+    return ret;
+}
+
+/*
+ * Gets all folders inside each type, for all domain types.
+ *
+ *  domain - Optional domain (overload), will check return domains if not.
+ *  type - The type of files, e.g. TEMPLATES
+ *  extensions - A list of extensions to return, e.g. xml, svg
+ *  exclusions - A list of names to exclude e.g. default.xml
+ */
+std::vector<Glib::ustring> get_foldernames(Type type, std::vector<const char *> const &exclusions)
+{
+    std::vector<Glib::ustring> ret;
+    get_foldernames_from_path(ret, get_path_ustring(USER, type), exclusions);
+    get_foldernames_from_path(ret, get_path_ustring(SHARED, type), exclusions);
+    get_foldernames_from_path(ret, get_path_ustring(SYSTEM, type), exclusions);
+    get_foldernames_from_path(ret, get_path_ustring(CREATE, type), exclusions);
+    return ret;
+}
+
+std::vector<Glib::ustring> get_foldernames(Domain domain, Type type, std::vector<const char *> const &exclusions)
+{
+    std::vector<Glib::ustring> ret;
+    get_foldernames_from_path(ret, get_path_ustring(domain, type), exclusions);
+    return ret;
+}
+std::vector<Glib::ustring> get_foldernames(Glib::ustring path, std::vector<const char *> const &exclusions)
+{
+    std::vector<Glib::ustring> ret;
+    get_foldernames_from_path(ret, path, exclusions);
+    return ret;
+}
+
+
+/*
+ * Get all the files from a specific path and any sub-dirs, populating &files vector
+ *
+ * &files - Output list to populate, will be populated with full paths
+ * path - The directory to parse, will add nothing if directory doesn't exist
+ * extensions - Only add files with these extensions, they must be duplicated
+ * exclusions - Exclude files that exactly match these names.
+ */
+void get_filenames_from_path(std::vector<Glib::ustring> &files, std::string const &path,
+                             std::vector<const char *> const &extensions, std::vector<const char *> const &exclusions)
+{
+    if(!Glib::file_test(path, Glib::FILE_TEST_IS_DIR)) {
+        return;
+    }
+
+    Glib::Dir dir(path);
+    std::string file = dir.read_name();
+    while (!file.empty()){
+        // If not extensions are specified, don't reject ANY files.
+        bool reject = !extensions.empty();
+
+        // Unreject any file which has one of the extensions.
+        for (auto &ext: extensions) {
+	    reject ^= Glib::str_has_suffix(file, ext);
+        }
+
+        // Reject any file which matches the exclusions.
+        for (auto &exc: exclusions) {
+	    reject |= Glib::str_has_prefix(file, exc);
+        }
+
+        // Reject any filename which isn't a regular file
+        auto filename = Glib::build_filename(path, file);
+
+        if(Glib::file_test(filename, Glib::FILE_TEST_IS_DIR)) {
+            get_filenames_from_path(files, filename, extensions, exclusions);
+        } else if(Glib::file_test(filename, Glib::FILE_TEST_IS_REGULAR) && !reject) {
+            files.push_back(Glib::filename_to_utf8(filename));
+        }
+        file = dir.read_name();
+    }
+}
+
+/*
+ * Get all the files from a specific path and any sub-dirs, populating &files vector
+ *
+ * &folders - Output list to populate, will be poulated with full paths
+ * path - The directory to parse, will add nothing if directory doesn't exist
+ * exclusions - Exclude files that exactly match these names.
+ */
+void get_foldernames_from_path(std::vector<Glib::ustring> &folders, Glib::ustring path,
+                               std::vector<const char *> exclusions)
+{
+    get_foldernames_from_path(folders, Glib::filename_from_utf8(path), exclusions);
+}
+
+void get_foldernames_from_path(std::vector<Glib::ustring> &folders, std::string const &path,
+                               std::vector<const char *> const &exclusions)
+{
+    if (!Glib::file_test(path, Glib::FILE_TEST_IS_DIR)) {
+        return;
+    }
+
+    Glib::Dir dir(path);
+    std::string file = dir.read_name();
+    while (!file.empty()) {
+        // If not extensions are specified, don't reject ANY files.
+        bool reject = false;
+
+        // Reject any file which matches the exclusions.
+        for (auto &exc : exclusions) {
+            reject |= Glib::str_has_prefix(file, exc);
+        }
+
+        // Reject any filename which isn't a regular file
+        auto filename = Glib::build_filename(path, file);
+
+        if (Glib::file_test(filename, Glib::FILE_TEST_IS_DIR) && !reject) {
+            folders.push_back(Glib::filename_to_utf8(filename));
+        }
+        file = dir.read_name();
+    }
+}
+
+
+/**
+ * Get, or guess, or decide the location where the preferences.xml
+ * file should be located. This also indicates where all other inkscape
+ * shared files may optionally exist.
+ */
+std::string profile_path(const char *filename)
+{
+    if (profile_path().empty()) {
+        return std::string("");
+    }
+    return Glib::build_filename(profile_path(), filename);
+}
+
+std::string profile_path()
+{
+    
+    static std::string prefdir = "";
+
+    if (prefdir.empty()) {
+        // Check if profile directory is overridden using environment variable
+        prefdir = Glib::getenv("INKSCAPE_PROFILE_DIR");
+#ifdef _WIN32
+        // prefer c:\Documents and Settings\UserName\Application Data\ to c:\Documents and Settings\userName\;
+        // TODO: CSIDL_APPDATA is C:\Users\UserName\AppData\Roaming these days
+        //       should we migrate to AppData\Local? Then we can simply use the portable g_get_user_config_dir()
+        if (prefdir.empty()) {
+            ITEMIDLIST *pidl = 0;
+            if ( SHGetFolderLocation( NULL, CSIDL_APPDATA, NULL, 0, &pidl ) == S_OK ) {
+                gchar * utf8Path = NULL;
+
+                {
+                    wchar_t pathBuf[MAX_PATH+1];
+                    g_assert(sizeof(wchar_t) == sizeof(gunichar2));
+
+                    if ( SHGetPathFromIDListW( pidl, pathBuf ) ) {
+                        utf8Path = g_utf16_to_utf8( (gunichar2*)(&pathBuf[0]), -1, NULL, NULL, NULL );
+                    }
+                }
+
+                if ( utf8Path ) {
+                    if (!g_utf8_validate(utf8Path, -1, NULL)) {
+                        g_warning( "SHGetPathFromIDListW() resulted in invalid UTF-8");
+                        g_free( utf8Path );
+                        utf8Path = 0;
+                    } else {
+                        prefdir = utf8Path;
+                    }
+                }
+            }
+
+            if (!prefdir.empty()) {
+                prefdir = Glib::build_filename(prefdir, INKSCAPE_PROFILE_DIR);
+            }
+        }
+#endif
+        if (prefdir.empty()) {
+            prefdir =  Glib::build_filename(get_user_config_dir(), INKSCAPE_PROFILE_DIR);
+            // In case the XDG user config dir of the moment does not yet exist...
+            int mode = S_IRWXU;
+#ifdef S_IRGRP
+            mode |= S_IRGRP;
+#endif
+#ifdef S_IXGRP
+            mode |= S_IXGRP;
+#endif
+#ifdef S_IXOTH
+            mode |= S_IXOTH;
+#endif
+            if (g_mkdir_with_parents(prefdir.c_str(), mode) == -1 ) {
+                int problem = errno;
+                g_warning("Unable to create profile directory (%s) (%d)", g_strerror(problem), problem);
+            } else {
+                gchar const *userDirs[] = { "keys", "templates", "icons", "extensions", "ui",
+                                            "symbols", "paint", "themes", "palettes", "fontcollections", nullptr };
+                for (gchar const** name = userDirs; *name; ++name) {
+                    gchar *dir = g_build_filename(prefdir.c_str(), *name, nullptr);
+                    g_mkdir_with_parents(dir, mode);
+                    g_free(dir);
+                }
+            }
+        }
+    }
+    return prefdir;
+}
+
+std::string shared_path(const char *filename)
+{
+    return shared_path().empty() ? shared_path() : Glib::build_filename(shared_path(), filename);
+}
+
+std::string shared_path()
+{
+    if (InkscapeApplication::instance()) {
+        Inkscape::Preferences *prefs = Inkscape::Preferences::get();
+        std::string shared_dir = prefs->getString("/options/resources/sharedpath");
+        if (!shared_dir.empty() && Glib::file_test(shared_dir, Glib::FILE_TEST_IS_DIR)) {
+            return shared_dir;
+        }
+    }
+    return std::string("");
+}
+
+/*
+ * We return the profile_path because that is where most documentation
+ * days log files will be generated in inkscape 0.92
+ */
+std::string log_path(const char *filename)
+{
+    return profile_path(filename);
+}
+
+std::string homedir_path()
+{
+    return g_get_home_dir();
+}
+
+}
+
+}
+
+}
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/io/resource.h b/src/io/resource.h
new file mode 100644
index 0000000..e2105de
--- /dev/null
+++ b/src/io/resource.h
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * TODO: insert short description here
+ *//*
+ * Authors:
+ *   MenTaLguY <mental@rydia.net>
+ *   Martin Owens <doctormo@gmail.com>
+ *
+ * Copyright (C) 2018 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#ifndef SEEN_INKSCAPE_IO_RESOURCE_H
+#define SEEN_INKSCAPE_IO_RESOURCE_H
+
+#include <vector>
+#include <glibmm/ustring.h>
+#include "util/share.h"
+
+namespace Inkscape {
+
+namespace IO {
+
+/**
+ * simple resource API
+ */
+namespace Resource {
+
+enum Type {
+    ATTRIBUTES,
+    EXAMPLES,
+    EXTENSIONS,
+    FONTS,
+    FONTCOLLECTIONS,
+    ICONS,
+    KEYS,
+    MARKERS,
+    NONE,
+    PAINT,
+    PALETTES,
+    SCREENS,
+    TEMPLATES,
+    TUTORIALS,
+    SYMBOLS,
+    FILTERS,
+    THEMES,
+    UIS,
+    PIXMAPS,
+    DOCS
+};
+
+enum Domain {
+    SYSTEM,
+    CREATE,
+    CACHE,
+    SHARED,
+    USER
+};
+
+Util::ptr_shared get_path(Domain domain, Type type,
+                                char const *filename=nullptr);
+
+Glib::ustring get_path_ustring(Domain domain, Type type,
+                                char const *filename=nullptr);
+std::string get_path_string(Domain domain, Type type, char const *filename = nullptr);
+
+std::string get_filename_string(Type type, char const *filename, bool localized = false, bool silent = false);
+Glib::ustring get_filename(Type type, char const *filename, bool localized = false, bool silent = false);
+// TODO consolidate with Glib::StdStringView
+Glib::ustring get_filename(Glib::ustring path, Glib::ustring filename);
+std::string get_filename(std::string const& path, std::string const& filename);
+inline std::string get_filename(const char *path, const char *filename)
+{
+    return get_filename(std::string(path), std::string(filename));
+}
+
+std::vector<Glib::ustring> get_filenames(Type type,
+                                std::vector<const char *> const &extensions={},
+                                std::vector<const char *> const &exclusions={});
+
+std::vector<Glib::ustring> get_filenames(Domain domain, Type type,
+                                std::vector<const char *> const &extensions={},
+                                std::vector<const char *> const &exclusions={});
+
+std::vector<Glib::ustring> get_filenames(Glib::ustring path,
+                                std::vector<const char *> const &extensions={},
+                                std::vector<const char *> const &exclusions={});
+
+std::vector<Glib::ustring> get_foldernames(Type type, std::vector<const char *> const &exclusions = {});
+
+std::vector<Glib::ustring> get_foldernames(Domain domain, Type type, std::vector<const char *> const &exclusions = {});
+
+std::vector<Glib::ustring> get_foldernames(Glib::ustring path, std::vector<const char *> const &exclusions = {});
+
+void get_foldernames_from_path(std::vector<Glib::ustring> &files, Glib::ustring path,
+                               std::vector<const char *> exclusions = {});
+
+void get_filenames_from_path(std::vector<Glib::ustring> &files, std::string const &path,
+                                    std::vector<const char *> const &extensions = {},
+                                    std::vector<const char *> const &exclusions = {});
+
+
+std::string profile_path();
+std::string profile_path(const char *filename);
+std::string shared_path();
+std::string shared_path(const char *filename);
+std::string homedir_path();
+std::string log_path(const char *filename);
+
+}
+
+}
+
+}
+
+#endif
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/io/stream/README b/src/io/stream/README
new file mode 100644
index 0000000..67d8721
--- /dev/null
+++ b/src/io/stream/README
@@ -0,0 +1,13 @@
+
+This directory contains code related to streams.
+
+Base class:
+  inkscapestream.h  Used by other stream handling code and odf, filter-file
+
+Derived classes:
+  bufferstream.h    Used by odf
+  gzipstream.h      Used by repr-io.cpp
+  stringstream.h    Used by rerp-io.cpp and ui/clipboard.cpp
+                    Note file with same name in src/svg
+  uristream.h       Used by repr-io.cpp
+  xsltstream.h      Used by none one (except testfile)
diff --git a/src/io/stream/bufferstream.cpp b/src/io/stream/bufferstream.cpp
new file mode 100644
index 0000000..1723ee1
--- /dev/null
+++ b/src/io/stream/bufferstream.cpp
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/**
+ * @file
+ * Phoebe DOM Implementation.
+ *
+ * This is a C++ approximation of the W3C DOM model, which follows
+ * fairly closely the specifications in the various .idl files, copies of
+ * which are provided for reference.  Most important is this one:
+ *
+ * http://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/idl-definitions.html
+ *//*
+ * Authors:
+ * see git history
+ *   Bob Jamison
+ *
+ * Copyright (C) 2018 Authors
+ * Released under GNU LGPL v2.1+, read the file 'COPYING' for more information.
+ */
+
+/**
+ * This class provided buffered endpoints for input and output.
+ */
+
+#include "bufferstream.h"
+
+namespace Inkscape
+{
+namespace IO
+{
+
+//#########################################################################
+//# B U F F E R    I N P U T    S T R E A M
+//#########################################################################
+/**
+ *
+ */
+BufferInputStream::BufferInputStream(
+           const std::vector<unsigned char> &sourceBuffer)
+           : buffer(sourceBuffer)
+{
+    position = 0;
+    closed = false;
+}
+
+/**
+ *
+ */
+BufferInputStream::~BufferInputStream()
+= default;
+
+/**
+ * Returns the number of bytes that can be read (or skipped over) from
+ * this input stream without blocking by the next caller of a method for
+ * this input stream.
+ */
+int BufferInputStream::available()
+{
+    if (closed)
+        return -1;
+    return buffer.size() - position;
+}
+
+
+/**
+ *  Closes this input stream and releases any system resources
+ *  associated with the stream.
+ */
+void BufferInputStream::close()
+{
+    closed = true;
+}
+
+/**
+ * Reads the next byte of data from the input stream.  -1 if EOF
+ */
+int BufferInputStream::get()
+{
+    if (closed)
+        return -1;
+    if (position >= (int)buffer.size())
+        return -1;
+    int ch = (int) buffer[position++];
+    return ch;
+}
+
+
+
+
+//#########################################################################
+//# B U F F E R    O U T P U T    S T R E A M
+//#########################################################################
+
+/**
+ *
+ */
+BufferOutputStream::BufferOutputStream()
+{
+    closed = false;
+}
+
+/**
+ *
+ */
+BufferOutputStream::~BufferOutputStream()
+= default;
+
+/**
+ * Closes this output stream and releases any system resources
+ * associated with this stream.
+ */
+void BufferOutputStream::close()
+{
+    closed = true;
+}
+
+/**
+ *  Flushes this output stream and forces any buffered output
+ *  bytes to be written out.
+ */
+void BufferOutputStream::flush()
+{
+    //nothing to do
+}
+
+/**
+ * Writes the specified byte to this output stream.
+ */
+int BufferOutputStream::put(char ch)
+{
+    if (closed)
+        return -1;
+    buffer.push_back(ch);
+    return 1;
+}
+
+
+
+
+}  //namespace IO
+}  //namespace Inkscape
+
+//#########################################################################
+//# E N D    O F    F I L E
+//#########################################################################
diff --git a/src/io/stream/bufferstream.h b/src/io/stream/bufferstream.h
new file mode 100644
index 0000000..811ab0d
--- /dev/null
+++ b/src/io/stream/bufferstream.h
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/**
+ * @file
+ * Phoebe DOM Implementation.
+ *
+ * This is a C++ approximation of the W3C DOM model, which follows
+ * fairly closely the specifications in the various .idl files, copies of
+ * which are provided for reference.  Most important is this one:
+ *
+ * http://www.w3.org/TR/2004/REC-DOM-Level-3-Core-20040407/idl-definitions.html
+ *//*
+ * Authors:
+ * see git history
+ *   Bob Jamison
+ *
+ * Copyright (C) 2018 Authors
+ * Released under GNU LGPL v2.1+, read the file 'COPYING' for more information.
+ */
+#ifndef SEEN_BUFFERSTREAM_H
+#define SEEN_BUFFERSTREAM_H
+
+
+#include <vector>
+#include "inkscapestream.h"
+
+
+namespace Inkscape
+{
+namespace IO
+{
+
+//#########################################################################
+//# S T R I N G    I N P U T    S T R E A M
+//#########################################################################
+
+/**
+ * This class is for reading character from a DOMString
+ *
+ */
+class BufferInputStream : public InputStream
+{
+
+public:
+
+    BufferInputStream(const std::vector<unsigned char> &sourceBuffer);
+    ~BufferInputStream() override;
+    int available() override;
+    void close() override;
+    int get() override;
+
+private:
+    const std::vector<unsigned char> &buffer;
+    long position;
+    bool closed;
+
+}; // class BufferInputStream
+
+
+
+
+//#########################################################################
+//# B U F F E R     O U T P U T    S T R E A M
+//#########################################################################
+
+/**
+ * This class is for sending a stream to a character buffer
+ *
+ */
+class BufferOutputStream : public OutputStream
+{
+
+public:
+
+    BufferOutputStream();
+    ~BufferOutputStream() override;
+    void close() override;
+    void flush() override;
+    int put(char ch) override;
+    virtual std::vector<unsigned char> &getBuffer()
+        { return buffer; }
+
+    virtual void clear()
+        { buffer.clear(); }
+
+private:
+    std::vector<unsigned char> buffer;
+    bool closed;
+
+}; // class BufferOutputStream
+
+
+
+}  //namespace IO
+}  //namespace Inkscape
+
+
+
+#endif // SEEN_BUFFERSTREAM_H
diff --git a/src/io/stream/gzipstream.cpp b/src/io/stream/gzipstream.cpp
new file mode 100644
index 0000000..d1aa760
--- /dev/null
+++ b/src/io/stream/gzipstream.cpp
@@ -0,0 +1,463 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+/** @file
+ * Zlib-enabled input and output streams
+ *//*
+ * Authors:
+ * see git history
+ * Bob Jamison <rjamison@titan.com>
+ * 
+ *
+ * Copyright (C) 2018 Authors
+ * Released under GNU LGPL v2.1+, read the file 'COPYING' for more information.
+ */
+/*
+ * This is a thin wrapper of libz calls, in order
+ * to provide a simple interface to our developers
+ * for gzip input and output.
+ */
+
+#include "gzipstream.h"
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <string>
+
+namespace Inkscape
+{
+namespace IO
+{
+
+//#########################################################################
+//# G Z I P    I N P U T    S T R E A M
+//#########################################################################
+
+#define OUT_SIZE 4000
+
+/**
+ *
+ */ 
+GzipInputStream::GzipInputStream(InputStream &sourceStream)
+                    : BasicInputStream(sourceStream),
+                      loaded(false),
+                      outputBuf(nullptr),
+                      srcBuf(nullptr),
+                      crc(0),
+                      srcCrc(0),
+                      srcSiz(0),
+                      srcLen(0),
+                      outputBufPos(0),
+                      outputBufLen(0)
+{
+    memset( &d_stream, 0, sizeof(d_stream) );
+}
+
+/**
+ *
+ */ 
+GzipInputStream::~GzipInputStream()
+{
+    close();
+    if ( srcBuf ) {
+      delete[] srcBuf;
+      srcBuf = nullptr;
+    }
+    if ( outputBuf ) {
+        delete[] outputBuf;
+        outputBuf = nullptr;
+    }
+}
+
+/**
+ * Returns the number of bytes that can be read (or skipped over) from
+ * this input stream without blocking by the next caller of a method for
+ * this input stream.
+ */ 
+int GzipInputStream::available()
+{
+    if (closed || !outputBuf)
+        return 0;
+    return outputBufLen - outputBufPos;
+}
+
+    
+/**
+ *  Closes this input stream and releases any system resources
+ *  associated with the stream.
+ */ 
+void GzipInputStream::close()
+{
+    if (closed)
+        return;
+
+    int zerr = inflateEnd(&d_stream);
+    if (zerr != Z_OK) {
+        printf("inflateEnd: Some kind of problem: %d\n", zerr);
+    }
+
+    if ( srcBuf ) {
+      delete[] srcBuf;
+      srcBuf = nullptr;
+    }
+    if ( outputBuf ) {
+        delete[] outputBuf;
+        outputBuf = nullptr;
+    }
+    closed = true;
+}
+    
+/**
+ * Reads the next byte of data from the input stream.  -1 if EOF
+ */ 
+int GzipInputStream::get()
+{
+    int ch = -1;
+    if (closed) {
+        // leave return value -1
+    }
+    else if (!loaded && !load()) {
+        closed=true;
+    } else {
+        loaded = true;
+
+        if ( outputBufPos >= outputBufLen ) {
+            // time to read more, if we can
+            fetchMore();
+        }
+
+        if ( outputBufPos < outputBufLen ) {
+            ch = (int)outputBuf[outputBufPos++];
+        }
+    }
+
+    return ch;
+}
+
+#define FTEXT 0x01
+#define FHCRC 0x02
+#define FEXTRA 0x04
+#define FNAME 0x08
+#define FCOMMENT 0x10
+
+bool GzipInputStream::load()
+{
+    crc = crc32(0L, Z_NULL, 0);
+    
+    std::vector<Byte> inputBuf;
+    while (true)
+        {
+        int ch = source.get();
+        if (ch<0)
+            break;
+        inputBuf.push_back(static_cast<Byte>(ch & 0xff));
+        }
+    long inputBufLen = inputBuf.size();
+    
+    if (inputBufLen < 19) //header + tail + 1
+        {
+        return false;
+        }
+
+    srcLen = inputBuf.size();
+    srcBuf = new (std::nothrow) Byte [srcLen];
+    if (!srcBuf) {
+        return false;
+    }
+
+    outputBuf = new (std::nothrow) unsigned char [OUT_SIZE];
+    if ( !outputBuf ) {
+        delete[] srcBuf;
+        srcBuf = nullptr;
+        return false;
+    }
+    outputBufLen = 0; // Not filled in yet
+
+    std::vector<unsigned char>::iterator iter;
+    Bytef *p = srcBuf;
+    for (iter=inputBuf.begin() ; iter != inputBuf.end() ; ++iter)
+	{
+        *p++ = *iter;
+	}
+
+    size_t headerLen = 10;
+
+    int flags = static_cast<int>(srcBuf[3]);
+
+    constexpr size_t size_XLEN = 2;
+    constexpr size_t size_CRC16 = 2;
+    constexpr size_t size_CRC32 = 4;
+    constexpr size_t size_ISIZE = 4;
+
+    auto const check_not_truncated = [&] { return headerLen + size_CRC32 + size_ISIZE <= srcLen; };
+
+    auto const skip_n = [&](size_t n) {
+        headerLen += n;
+        return check_not_truncated();
+    };
+
+    auto const skip_zero_terminated = [&] {
+        while (headerLen < srcLen && srcBuf[headerLen++]) {
+        }
+        return check_not_truncated();
+    };
+
+    if (flags & FEXTRA) {
+        if (!skip_n(size_XLEN)) {
+            return false;
+        }
+        auto const xlen = size_t(srcBuf[headerLen - 2]) | //
+                          size_t(srcBuf[headerLen - 1] << 8);
+        if (!skip_n(xlen)) {
+            return false;
+        }
+    }
+
+    if ((flags & FNAME) && !skip_zero_terminated()) {
+        return false;
+    }
+
+    if ((flags & FCOMMENT) && !skip_zero_terminated()) {
+        return false;
+    }
+
+    if ((flags & FHCRC) && !skip_n(size_CRC16)) {
+        return false;
+    }
+
+    if (!check_not_truncated()) {
+        return false;
+    }
+
+    srcCrc = ((0x0ff & srcBuf[srcLen - 5]) << 24)
+           | ((0x0ff & srcBuf[srcLen - 6]) << 16)
+           | ((0x0ff & srcBuf[srcLen - 7]) <<  8)
+           | ((0x0ff & srcBuf[srcLen - 8]) <<  0);
+    //printf("srcCrc:%lx\n", srcCrc);
+    
+    srcSiz = ((0x0ff & srcBuf[srcLen - 1]) << 24)
+           | ((0x0ff & srcBuf[srcLen - 2]) << 16)
+           | ((0x0ff & srcBuf[srcLen - 3]) <<  8)
+           | ((0x0ff & srcBuf[srcLen - 4]) <<  0);
+    //printf("srcSiz:%lx/%ld\n", srcSiz, srcSiz);
+    
+    //outputBufLen = srcSiz + srcSiz/100 + 14;
+    
+    unsigned char *data = srcBuf + headerLen;
+    unsigned long dataLen = srcLen - (headerLen + 8);
+    //printf("%x %x\n", data[0], data[dataLen-1]);
+    
+    d_stream.zalloc    = (alloc_func)nullptr;
+    d_stream.zfree     = (free_func)nullptr;
+    d_stream.opaque    = (voidpf)nullptr;
+    d_stream.next_in   = data;
+    d_stream.avail_in  = dataLen;
+    d_stream.next_out  = outputBuf;
+    d_stream.avail_out = OUT_SIZE;
+    
+    int zerr = inflateInit2(&d_stream, -MAX_WBITS);
+    if ( zerr == Z_OK )
+    {
+        zerr = fetchMore();
+    } else {
+        printf("inflateInit2: Some kind of problem: %d\n", zerr);
+    }
+
+        
+    return (zerr == Z_OK) || (zerr == Z_STREAM_END);
+}
+
+
+int GzipInputStream::fetchMore()
+{
+    // TODO assumes we aren't called till the buffer is empty
+    d_stream.next_out  = outputBuf;
+    d_stream.avail_out = OUT_SIZE;
+    outputBufLen = 0;
+    outputBufPos = 0;
+
+    int zerr = inflate( &d_stream, Z_SYNC_FLUSH );
+    if ( zerr == Z_OK || zerr == Z_STREAM_END ) {
+        outputBufLen = OUT_SIZE - d_stream.avail_out;
+        if ( outputBufLen ) {
+            crc = crc32(crc, const_cast<const Bytef *>(outputBuf), outputBufLen);
+        }
+        //printf("crc:%lx\n", crc);
+//     } else if ( zerr != Z_STREAM_END ) {
+//         // TODO check to be sure this won't happen for partial end reads
+//         printf("inflate: Some kind of problem: %d\n", zerr);
+    }
+
+    return zerr;
+}
+
+//#########################################################################
+//# G Z I P   O U T P U T    S T R E A M
+//#########################################################################
+
+/**
+ *
+ */ 
+GzipOutputStream::GzipOutputStream(OutputStream &destinationStream)
+                     : BasicOutputStream(destinationStream)
+{
+
+    totalIn         = 0;
+    totalOut        = 0;
+    crc             = crc32(0L, Z_NULL, 0);
+
+    //Gzip header
+    destination.put(0x1f);
+    destination.put(0x8b);
+
+    //Say it is compressed
+    destination.put(Z_DEFLATED);
+
+    //flags
+    destination.put(0);
+
+    //time
+    destination.put(0);
+    destination.put(0);
+    destination.put(0);
+    destination.put(0);
+
+    //xflags
+    destination.put(0);
+
+    //OS code - from zutil.h
+    //destination.put(OS_CODE);
+    //apparently, we should not explicitly include zutil.h
+    destination.put(0);
+
+}
+
+/**
+ *
+ */ 
+GzipOutputStream::~GzipOutputStream()
+{
+    close();
+}
+
+/**
+ * Closes this output stream and releases any system resources
+ * associated with this stream.
+ */ 
+void GzipOutputStream::close()
+{
+    if (closed)
+        return;
+
+    flush();
+
+    //# Send the CRC
+    uLong outlong = crc;
+    for (int n = 0; n < 4; n++)
+        {
+        destination.put(static_cast<char>(outlong & 0xff));
+        outlong >>= 8;
+        }
+    //# send the file length
+    outlong = totalIn & 0xffffffffL;
+    for (int n = 0; n < 4; n++)
+        {
+        destination.put(static_cast<char>(outlong & 0xff));
+        outlong >>= 8;
+        }
+
+    destination.close();
+    closed = true;
+}
+    
+/**
+ *  Flushes this output stream and forces any buffered output
+ *  bytes to be written out.
+ */ 
+void GzipOutputStream::flush()
+{
+    if (closed || inputBuf.empty())
+	{
+        return;
+    }
+	
+    uLong srclen = inputBuf.size();
+    Bytef *srcbuf = new (std::nothrow) Bytef [srclen];
+    if (!srcbuf)
+        {
+        return;
+        }
+        
+    uLong destlen = srclen;
+    Bytef *destbuf = new (std::nothrow) Bytef [(destlen + (srclen/100) + 13)];
+    if (!destbuf)
+        {
+        delete[] srcbuf;
+        return;
+        }
+        
+    std::vector<unsigned char>::iterator iter;
+    Bytef *p = srcbuf;
+    for (iter=inputBuf.begin() ; iter != inputBuf.end() ; ++iter)
+        *p++ = *iter;
+        
+    crc = crc32(crc, const_cast<const Bytef *>(srcbuf), srclen);
+    
+    int zerr = compress(destbuf, static_cast<uLongf *>(&destlen), srcbuf, srclen);
+    if (zerr != Z_OK)
+        {
+        printf("Some kind of problem\n");
+        }
+
+    totalOut += destlen;
+    //skip the redundant zlib header and checksum
+    for (uLong i=2; i<destlen-4 ; i++)
+        {
+        destination.put((int)destbuf[i]);
+        }
+        
+    destination.flush();
+
+    inputBuf.clear();
+    delete[] srcbuf;
+    delete[] destbuf;
+}
+
+
+
+/**
+ * Writes the specified byte to this output stream.
+ */ 
+int GzipOutputStream::put(char ch)
+{
+    if (closed)
+        {
+        //probably throw an exception here
+        return -1;
+        }
+
+
+    //Add char to buffer
+    inputBuf.push_back(ch);
+    totalIn++;
+    return 1;
+}
+
+
+
+} // namespace IO
+} // namespace Inkscape
+
+
+//#########################################################################
+//# E N D    O F    F I L E
+//#########################################################################
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/io/stream/gzipstream.h b/src/io/stream/gzipstream.h
new file mode 100644
index 0000000..202b3a1
--- /dev/null
+++ b/src/io/stream/gzipstream.h
@@ -0,0 +1,120 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_INKSCAPE_IO_GZIPSTREAM_H
+#define SEEN_INKSCAPE_IO_GZIPSTREAM_H
+/**
+ * @file
+ * Zlib-enabled input and output streams.
+ *
+ * This is a thin wrapper of libz calls, in order
+ * to provide a simple interface to our developers
+ * for gzip input and output.
+ */
+/*
+ * Authors:
+ *   Bob Jamison <rjamison@titan.com>
+ *
+ * Copyright (C) 2004 Inkscape.org
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <vector>
+#include "inkscapestream.h"
+#include <zlib.h>
+
+namespace Inkscape
+{
+namespace IO
+{
+
+//#########################################################################
+//# G Z I P    I N P U T    S T R E A M
+//#########################################################################
+
+/**
+ * This class is for deflating a gzip-compressed InputStream source
+ *
+ */
+class GzipInputStream : public BasicInputStream
+{
+
+public:
+
+    GzipInputStream(InputStream &sourceStream);
+    
+    ~GzipInputStream() override;
+    
+    int available() override;
+    
+    void close() override;
+    
+    int get() override;
+    
+private:
+
+    bool load();
+    int fetchMore();
+
+    bool loaded;
+    
+    unsigned char *outputBuf;
+    unsigned char *srcBuf;
+
+    unsigned long crc;
+    unsigned long srcCrc;
+    unsigned long srcSiz;
+    unsigned long srcLen;
+    long outputBufPos;
+    long outputBufLen;
+
+    z_stream d_stream;
+}; // class GzipInputStream
+
+
+
+
+//#########################################################################
+//# G Z I P    O U T P U T    S T R E A M
+//#########################################################################
+
+/**
+ * This class is for gzip-compressing data going to the
+ * destination OutputStream
+ *
+ */
+class GzipOutputStream : public BasicOutputStream
+{
+
+public:
+
+    GzipOutputStream(OutputStream &destinationStream);
+    
+    ~GzipOutputStream() override;
+    
+    void close() override;
+    
+    void flush() override;
+    
+    int put(char ch) override;
+
+private:
+
+    std::vector<unsigned char> inputBuf;
+
+    long totalIn;
+    long totalOut;
+    unsigned long crc;
+
+}; // class GzipOutputStream
+
+
+
+
+
+
+
+} // namespace IO
+} // namespace Inkscape
+
+
+#endif /* __INKSCAPE_IO_GZIPSTREAM_H__ */
diff --git a/src/io/stream/inkscapestream.cpp b/src/io/stream/inkscapestream.cpp
new file mode 100644
index 0000000..bc6dc1d
--- /dev/null
+++ b/src/io/stream/inkscapestream.cpp
@@ -0,0 +1,800 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Our base input/output stream classes.  These are is directly
+ * inherited from iostreams, and includes any extra
+ * functionality that we might need.
+ *
+ * Authors:
+ *   Bob Jamison <rjamison@titan.com>
+ *
+ * Copyright (C) 2004 Inkscape.org
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <cstdlib>
+#include "inkscapestream.h"
+
+namespace Inkscape
+{
+namespace IO
+{
+
+//#########################################################################
+//# U T I L I T Y
+//#########################################################################
+
+void pipeStream(InputStream &source, OutputStream &dest)
+{
+    for (;;)
+        {
+        int ch = source.get();
+        if (ch<0)
+            break;
+        dest.put(ch);
+        }
+    dest.flush();
+}
+
+//#########################################################################
+//# B A S I C    I N P U T    S T R E A M
+//#########################################################################
+
+
+/**
+ *
+ */ 
+BasicInputStream::BasicInputStream(InputStream &sourceStream)
+                   : source(sourceStream)
+{
+    closed = false;
+}
+
+/**
+ * Returns the number of bytes that can be read (or skipped over) from
+ * this input stream without blocking by the next caller of a method for
+ * this input stream.
+ */ 
+int BasicInputStream::available()
+{
+    if (closed)
+        return 0;
+    return source.available();
+}
+
+    
+/**
+ *  Closes this input stream and releases any system resources
+ *  associated with the stream.
+ */ 
+void BasicInputStream::close()
+{
+    if (closed)
+        return;
+    source.close();
+    closed = true;
+}
+    
+/**
+ * Reads the next byte of data from the input stream.  -1 if EOF
+ */ 
+int BasicInputStream::get()
+{
+    if (closed)
+        return -1;
+    return source.get();
+}
+   
+
+
+//#########################################################################
+//# B A S I C    O U T P U T    S T R E A M
+//#########################################################################
+
+/**
+ *
+ */ 
+BasicOutputStream::BasicOutputStream(OutputStream &destinationStream)
+                     : destination(destinationStream)
+{
+    closed = false;
+}
+
+/**
+ * Closes this output stream and releases any system resources
+ * associated with this stream.
+ */ 
+void BasicOutputStream::close()
+{
+    if (closed)
+        return;
+    destination.close();
+    closed = true;
+}
+    
+/**
+ *  Flushes this output stream and forces any buffered output
+ *  bytes to be written out.
+ */ 
+void BasicOutputStream::flush()
+{
+    if (closed)
+        return;
+    destination.flush();
+}
+    
+/**
+ * Writes the specified byte to this output stream.
+ */ 
+int BasicOutputStream::put(char ch)
+{
+    if (closed)
+        return -1;
+    destination.put(ch);
+    return 1;
+}
+
+
+
+//#########################################################################
+//# B A S I C    R E A D E R
+//#########################################################################
+/**
+ *
+ */ 
+BasicReader::BasicReader(Reader &sourceReader)
+{
+    source = &sourceReader;
+}
+
+/**
+ * Returns the number of bytes that can be read (or skipped over) from
+ * this reader without blocking by the next caller of a method for
+ * this reader.
+ */ 
+int BasicReader::available()
+{
+    if (source)
+        return source->available();
+    else
+        return 0;
+}
+
+    
+/**
+ *  Closes this reader and releases any system resources
+ *  associated with the reader.
+ */ 
+void BasicReader::close()
+{
+    if (source)
+        source->close();
+}
+    
+/**
+ * Reads the next byte of data from the reader.
+ */ 
+char BasicReader::get()
+{
+    if (source)
+        return source->get();
+    else
+        return (char)-1;
+}
+   
+
+/**
+ * Reads a line of data from the reader.
+ */ 
+Glib::ustring BasicReader::readLine()
+{
+    Glib::ustring str;
+    while (available() > 0)
+        {
+        char ch = get();
+        if (ch == '\n')
+            break;
+        str.push_back(ch);
+        }
+    return str;
+}
+   
+/**
+ * Reads a line of data from the reader.
+ */ 
+Glib::ustring BasicReader::readWord()
+{
+    Glib::ustring str;
+    while (available() > 0)
+        {
+        char ch = get();
+        if (!std::isprint(ch))
+            break;
+        str.push_back(ch);
+        }
+    return str;
+}
+   
+
+static bool getLong(Glib::ustring &str, long *val)
+{
+    const char *begin = str.raw().c_str();
+    char *end;
+    long ival = strtol(begin, &end, 10);
+    if (str == end)
+        return false;
+    *val = ival;
+    return true;
+}
+
+static bool getULong(Glib::ustring &str, unsigned long *val)
+{
+    const char *begin = str.raw().c_str();
+    char *end;
+    unsigned long ival = strtoul(begin, &end, 10);
+    if (str == end)
+        return false;
+    *val = ival;
+    return true;
+}
+
+static bool getDouble(Glib::ustring &str, double *val)
+{
+    const char *begin = str.raw().c_str();
+    char *end;
+    double ival = strtod(begin, &end);
+    if (str == end)
+        return false;
+    *val = ival;
+    return true;
+}
+
+
+
+const Reader &BasicReader::readBool (bool& val )
+{
+    Glib::ustring buf = readWord();
+    if (buf == "true")
+        val = true;
+    else
+        val = false;
+    return *this;
+}
+
+const Reader &BasicReader::readShort (short& val )
+{
+    Glib::ustring buf = readWord();
+    long ival;
+    if (getLong(buf, &ival))
+        val = (short) ival;
+    return *this;
+}
+
+const Reader &BasicReader::readUnsignedShort (unsigned short& val )
+{
+    Glib::ustring buf = readWord();
+    unsigned long ival;
+    if (getULong(buf, &ival))
+        val = (unsigned short) ival;
+    return *this;
+}
+
+const Reader &BasicReader::readInt (int& val )
+{
+    Glib::ustring buf = readWord();
+    long ival;
+    if (getLong(buf, &ival))
+        val = (int) ival;
+    return *this;
+}
+
+const Reader &BasicReader::readUnsignedInt (unsigned int& val )
+{
+    Glib::ustring buf = readWord();
+    unsigned long ival;
+    if (getULong(buf, &ival))
+        val = (unsigned int) ival;
+    return *this;
+}
+
+const Reader &BasicReader::readLong (long& val )
+{
+    Glib::ustring buf = readWord();
+    long ival;
+    if (getLong(buf, &ival))
+        val = ival;
+    return *this;
+}
+
+const Reader &BasicReader::readUnsignedLong (unsigned long& val )
+{
+    Glib::ustring buf = readWord();
+    unsigned long ival;
+    if (getULong(buf, &ival))
+        val = ival;
+    return *this;
+}
+
+const Reader &BasicReader::readFloat (float& val )
+{
+    Glib::ustring buf = readWord();
+    double ival;
+    if (getDouble(buf, &ival))
+        val = (float)ival;
+    return *this;
+}
+
+const Reader &BasicReader::readDouble (double& val )
+{
+    Glib::ustring buf = readWord();
+    double ival;
+    if (getDouble(buf, &ival))
+        val = ival;
+    return *this;
+}
+
+
+
+//#########################################################################
+//# I N P U T    S T R E A M    R E A D E R
+//#########################################################################
+
+
+InputStreamReader::InputStreamReader(InputStream &inputStreamSource)
+                     : inputStream(inputStreamSource)
+{
+}
+
+    
+
+/**
+ *  Close the underlying OutputStream
+ */
+void InputStreamReader::close()
+{
+    inputStream.close();
+}
+    
+/**
+ *  Flush the underlying OutputStream
+ */
+int InputStreamReader::available()
+{
+    return inputStream.available();
+}
+    
+/**
+ *  Overloaded to receive its bytes from an InputStream
+ *  rather than a Reader
+ */
+char InputStreamReader::get()
+{
+    char ch = inputStream.get();
+    return ch;
+}
+
+
+
+//#########################################################################
+//# S T D    R E A D E R
+//#########################################################################
+
+
+/**
+ *
+ */
+StdReader::StdReader()
+{
+    inputStream = new StdInputStream();
+}
+
+/**
+ *
+ */
+StdReader::~StdReader()
+{
+    delete inputStream;
+}
+
+    
+
+/**
+ *  Close the underlying OutputStream
+ */
+void StdReader::close()
+{
+    inputStream->close();
+}
+    
+/**
+ *  Flush the underlying OutputStream
+ */
+int StdReader::available()
+{
+    return inputStream->available();
+}
+    
+/**
+ *  Overloaded to receive its bytes from an InputStream
+ *  rather than a Reader
+ */
+char StdReader::get()
+{
+    char ch = inputStream->get();
+    return ch;
+}
+
+
+
+
+
+//#########################################################################
+//# B A S I C    W R I T E R
+//#########################################################################
+
+/**
+ *
+ */ 
+BasicWriter::BasicWriter(Writer &destinationWriter)
+{
+    destination = &destinationWriter;
+}
+
+/**
+ * Closes this writer and releases any system resources
+ * associated with this writer.
+ */ 
+void BasicWriter::close()
+{
+    if (destination)
+        destination->close();
+}
+    
+/**
+ *  Flushes this output stream and forces any buffered output
+ *  bytes to be written out.
+ */ 
+void BasicWriter::flush()
+{
+    if (destination)
+        destination->flush();
+}
+    
+/**
+ * Writes the specified byte to this output writer.
+ */ 
+void BasicWriter::put(char ch)
+{
+    if (destination)
+        destination->put(ch);
+}
+
+/**
+ * Provide printf()-like formatting
+ */ 
+Writer &BasicWriter::printf(char const *fmt, ...)
+{
+    va_list args;
+    va_start(args, fmt);
+    gchar *buf = g_strdup_vprintf(fmt, args);
+    va_end(args);
+    if (buf) {
+        writeString(buf);
+        g_free(buf);
+    }
+    return *this;
+}
+/**
+ * Writes the specified character to this output writer.
+ */ 
+Writer &BasicWriter::writeChar(char ch)
+{
+    put(ch);
+    return *this;
+}
+
+
+/**
+ * Writes the specified unicode string to this output writer.
+ */ 
+Writer &BasicWriter::writeUString(const Glib::ustring &str)
+{
+    writeStdString(str.raw());
+    return *this;
+}
+
+/**
+ * Writes the specified standard string to this output writer.
+ */ 
+Writer &BasicWriter::writeStdString(const std::string &str)
+{
+    for (char it : str) {
+        put(it);
+    }
+    return *this;
+}
+
+/**
+ * Writes the specified character string to this output writer.
+ */ 
+Writer &BasicWriter::writeString(const char *str)
+{
+    std::string tmp;
+    if (str)
+        tmp = str;
+    else
+        tmp = "null";
+    writeStdString(tmp);
+    return *this;
+}
+
+
+
+
+/**
+ *
+ */
+Writer &BasicWriter::writeBool (bool val )
+{
+    if (val)
+        writeString("true");
+    else
+        writeString("false");
+    return *this;
+}
+
+
+/**
+ *
+ */
+Writer &BasicWriter::writeShort (short val )
+{
+    gchar *buf = g_strdup_printf("%d", val);
+    if (buf) {
+        writeString(buf);
+        g_free(buf);
+    }
+  return *this;
+}
+
+
+
+/**
+ *
+ */
+Writer &BasicWriter::writeUnsignedShort (unsigned short val )
+{
+    gchar *buf = g_strdup_printf("%u", val);
+    if (buf) {
+        writeString(buf);
+        g_free(buf);
+    }
+    return *this;
+}
+
+/**
+ *
+ */
+Writer &BasicWriter::writeInt (int val)
+{
+    gchar *buf = g_strdup_printf("%d", val);
+    if (buf) {
+        writeString(buf);
+        g_free(buf);
+    }
+    return *this;
+}
+
+/**
+ *
+ */
+Writer &BasicWriter::writeUnsignedInt (unsigned int val)
+{
+    gchar *buf = g_strdup_printf("%u", val);
+    if (buf) {
+        writeString(buf);
+        g_free(buf);
+    }
+    return *this;
+}
+
+/**
+ *
+ */
+Writer &BasicWriter::writeLong (long val)
+{
+    gchar *buf = g_strdup_printf("%ld", val);
+    if (buf) {
+        writeString(buf);
+        g_free(buf);
+    }
+    return *this;
+}
+
+/**
+ *
+ */
+Writer &BasicWriter::writeUnsignedLong(unsigned long val)
+{
+    gchar *buf = g_strdup_printf("%lu", val);
+    if (buf) {
+        writeString(buf);
+        g_free(buf);
+    }
+    return *this;
+}
+
+/**
+ *
+ */
+Writer &BasicWriter::writeFloat(float val)
+{
+#if 1
+    gchar *buf = g_strdup_printf("%8.3f", val);
+    if (buf) {
+        writeString(buf);
+        g_free(buf);
+    }
+#else
+    std::string tmp = ftos(val, 'g', 8, 3, 0);
+    writeStdString(tmp);
+#endif
+    return *this;
+}
+
+/**
+ *
+ */
+Writer &BasicWriter::writeDouble(double val)
+{
+#if 1
+    gchar *buf = g_strdup_printf("%8.3f", val);
+    if (buf) {
+        writeString(buf);
+        g_free(buf);
+    }
+#else
+    std::string tmp = ftos(val, 'g', 8, 3, 0);
+    writeStdString(tmp);
+#endif
+    return *this;
+}
+
+
+Writer& operator<< (Writer &writer, char val)
+    { return writer.writeChar(val); }
+
+Writer& operator<< (Writer &writer, Glib::ustring &val)
+    { return writer.writeUString(val); }
+
+Writer& operator<< (Writer &writer, std::string &val)
+    { return writer.writeStdString(val); }
+
+Writer& operator<< (Writer &writer, char const *val)
+    { return writer.writeString(val); }
+
+Writer& operator<< (Writer &writer, bool val)
+    { return writer.writeBool(val); }
+
+Writer& operator<< (Writer &writer, short val)
+    { return writer.writeShort(val); }
+
+Writer& operator<< (Writer &writer, unsigned short val)
+    { return writer.writeUnsignedShort(val); }
+
+Writer& operator<< (Writer &writer, int val)
+    { return writer.writeInt(val); }
+
+Writer& operator<< (Writer &writer, unsigned int val)
+    { return writer.writeUnsignedInt(val); }
+
+Writer& operator<< (Writer &writer, long val)
+    { return writer.writeLong(val); }
+
+Writer& operator<< (Writer &writer, unsigned long val)
+    { return writer.writeUnsignedLong(val); }
+
+Writer& operator<< (Writer &writer, float val)
+    { return writer.writeFloat(val); }
+
+Writer& operator<< (Writer &writer, double val)
+    { return writer.writeDouble(val); }
+
+
+
+//#########################################################################
+//# O U T P U T    S T R E A M    W R I T E R
+//#########################################################################
+
+
+OutputStreamWriter::OutputStreamWriter(OutputStream &outputStreamDest)
+                     : outputStream(outputStreamDest)
+{
+}
+
+    
+
+/**
+ *  Close the underlying OutputStream
+ */
+void OutputStreamWriter::close()
+{
+    flush();
+    outputStream.close();
+}
+    
+/**
+ *  Flush the underlying OutputStream
+ */
+void OutputStreamWriter::flush()
+{
+      outputStream.flush();
+}
+    
+/**
+ *  Overloaded to redirect the output chars from the next Writer
+ *  in the chain to an OutputStream instead.
+ */
+void OutputStreamWriter::put(char ch)
+{
+    outputStream.put(ch);
+}
+
+//#########################################################################
+//# S T D    W R I T E R
+//#########################################################################
+
+
+/**
+ *  
+ */
+StdWriter::StdWriter()
+{
+    outputStream = new StdOutputStream();
+}
+
+    
+/**
+ *  
+ */
+StdWriter::~StdWriter()
+{
+    delete outputStream;
+}
+
+    
+
+/**
+ *  Close the underlying OutputStream
+ */
+void StdWriter::close()
+{
+    flush();
+    outputStream->close();
+}
+    
+/**
+ *  Flush the underlying OutputStream
+ */
+void StdWriter::flush()
+{
+      outputStream->flush();
+}
+    
+/**
+ *  Overloaded to redirect the output chars from the next Writer
+ *  in the chain to an OutputStream instead.
+ */
+void StdWriter::put(char ch)
+{
+    outputStream->put(ch);
+}
+
+
+} // namespace IO
+} // namespace Inkscape
+
+
+//#########################################################################
+//# E N D    O F    F I L E
+//#########################################################################
diff --git a/src/io/stream/inkscapestream.h b/src/io/stream/inkscapestream.h
new file mode 100644
index 0000000..b20899a
--- /dev/null
+++ b/src/io/stream/inkscapestream.h
@@ -0,0 +1,670 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_INKSCAPE_IO_INKSCAPESTREAM_H
+#define SEEN_INKSCAPE_IO_INKSCAPESTREAM_H
+/*
+ * Authors:
+ *   Bob Jamison <rjamison@titan.com>
+ *
+ * Copyright (C) 2004 Inkscape.org
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <cstdio>
+#include <glibmm/ustring.h>
+
+#ifdef printf
+#undef printf
+#endif
+
+namespace Inkscape
+{
+namespace IO
+{
+
+class StreamException : public std::exception
+{
+public:
+    StreamException(Glib::ustring theReason) noexcept
+        : reason(std::move(theReason))
+    {}
+    ~StreamException() noexcept override
+        = default;
+    char const *what() const noexcept override
+        { return reason.c_str(); }
+        
+private:
+    Glib::ustring reason;
+
+};
+
+//#########################################################################
+//# I N P U T    S T R E A M
+//#########################################################################
+
+/**
+ * This interface is the base of all input stream classes.  Users who wish
+ * to make an InputStream that is part of a chain should inherit from
+ * BasicInputStream.  Inherit from this class to make a source endpoint,
+ * such as a URI or buffer.
+ *
+ */
+class InputStream
+{
+
+public:
+
+    /**
+     * Constructor.
+     */
+    InputStream() = default;
+
+    /**
+     * Destructor
+     */
+    virtual ~InputStream() = default;
+
+    /**
+     * Return the number of bytes that are currently available
+     * to be read
+     */
+    virtual int available() = 0;
+    
+    /**
+     * Do whatever it takes to 'close' this input stream
+     * The most likely implementation of this method will be
+     * for endpoints that use a resource for their data.
+     */
+    virtual void close() = 0;
+    
+    /**
+     * Read one byte from this input stream.  This is a blocking
+     * call.  If no data is currently available, this call will
+     * not return until it exists.  If the user does not want
+     * their code to block,  then the usual solution is:
+     *     if (available() > 0)
+     *         myChar = get();
+     * This call returns -1 on end-of-file.
+     */
+    virtual int get() = 0;
+    
+}; // class InputStream
+
+
+
+
+/**
+ * This is the class that most users should inherit, to provide
+ * their own streams.
+ *
+ */
+class BasicInputStream : public InputStream
+{
+
+public:
+
+    BasicInputStream(InputStream &sourceStream);
+    
+    ~BasicInputStream() override = default;
+    
+    int available() override;
+    
+    void close() override;
+    
+    int get() override;
+    
+protected:
+
+    bool closed;
+
+    InputStream &source;
+    
+private:
+
+
+}; // class BasicInputStream
+
+
+
+/**
+ * Convenience class for reading from standard input
+ */
+class StdInputStream : public InputStream
+{
+public:
+
+    int available() override
+        { return 0; }
+    
+    void close() override
+        { /* do nothing */ }
+    
+    int get() override
+        {  return getchar(); }
+
+};
+
+
+
+
+
+
+//#########################################################################
+//# O U T P U T    S T R E A M
+//#########################################################################
+
+/**
+ * This interface is the base of all input stream classes.  Users who wish
+ * to make an OutputStream that is part of a chain should inherit from
+ * BasicOutputStream.  Inherit from this class to make a destination endpoint,
+ * such as a URI or buffer.
+ */
+class OutputStream
+{
+
+public:
+
+    /**
+     * Constructor.
+     */
+    OutputStream() = default;
+
+    /**
+     * Destructor
+     */
+    virtual ~OutputStream() = default;
+
+    /**
+     * This call should
+     *  1.  flush itself
+     *  2.  close itself
+     *  3.  close the destination stream
+     */
+    virtual void close() = 0;
+    
+    /**
+     * This call should push any pending data it might have to
+     * the destination stream.  It should NOT call flush() on
+     * the destination stream.
+     */
+    virtual void flush() = 0;
+    
+    /**
+     * Send one byte to the destination stream.
+     */
+    virtual int put(char ch) = 0;
+
+
+}; // class OutputStream
+
+
+/**
+ * This is the class that most users should inherit, to provide
+ * their own output streams.
+ */
+class BasicOutputStream : public OutputStream
+{
+
+public:
+
+    BasicOutputStream(OutputStream &destinationStream);
+    
+    ~BasicOutputStream() override = default;
+
+    void close() override;
+    
+    void flush() override;
+    
+    int put(char ch) override;
+
+protected:
+
+    bool closed;
+
+    OutputStream &destination;
+
+
+}; // class BasicOutputStream
+
+
+
+/**
+ * Convenience class for writing to standard output
+ */
+class StdOutputStream : public OutputStream
+{
+public:
+
+    void close() override
+        { }
+    
+    void flush() override
+        { }
+    
+    int put(char ch) override
+        {return  putchar(ch); }
+
+};
+
+
+
+
+//#########################################################################
+//# R E A D E R
+//#########################################################################
+
+
+/**
+ * This interface and its descendants are for unicode character-oriented input
+ *
+ */
+class Reader
+{
+
+public:
+
+    /**
+     * Constructor.
+     */
+    Reader() = default;
+
+    /**
+     * Destructor
+     */
+    virtual ~Reader() = default;
+
+
+    virtual int available() = 0;
+    
+    virtual void close() = 0;
+    
+    virtual char get() = 0;
+    
+    virtual Glib::ustring readLine() = 0;
+    
+    virtual Glib::ustring readWord() = 0;
+    
+    /* Input formatting */
+    virtual const Reader& readBool (bool& val ) = 0;
+    virtual const Reader& operator>> (bool& val ) = 0;
+        
+    virtual const Reader& readShort (short &val) = 0;
+    virtual const Reader& operator>> (short &val) = 0;
+        
+    virtual const Reader& readUnsignedShort (unsigned short &val) = 0;
+    virtual const Reader& operator>> (unsigned short &val) = 0;
+        
+    virtual const Reader& readInt (int &val) = 0;
+    virtual const Reader& operator>> (int &val) = 0;
+        
+    virtual const Reader& readUnsignedInt (unsigned int &val) = 0;
+    virtual const Reader& operator>> (unsigned int &val) = 0;
+        
+    virtual const Reader& readLong (long &val) = 0;
+    virtual const Reader& operator>> (long &val) = 0;
+        
+    virtual const Reader& readUnsignedLong (unsigned long &val) = 0;
+    virtual const Reader& operator>> (unsigned long &val) = 0;
+        
+    virtual const Reader& readFloat (float &val) = 0;
+    virtual const Reader& operator>> (float &val) = 0;
+        
+    virtual const Reader& readDouble (double &val) = 0;
+    virtual const Reader& operator>> (double &val) = 0;
+
+}; // interface Reader
+
+
+
+/**
+ * This class and its descendants are for unicode character-oriented input
+ *
+ */
+class BasicReader : public Reader
+{
+
+public:
+
+    BasicReader(Reader &sourceStream);
+    
+    ~BasicReader() override = default;
+
+    int available() override;
+    
+    void close() override;
+    
+    char get() override;
+    
+    Glib::ustring readLine() override;
+    
+    Glib::ustring readWord() override;
+    
+    /* Input formatting */
+    const Reader& readBool (bool& val ) override;
+    const Reader& operator>> (bool& val ) override
+        { return readBool(val); }
+        
+    const Reader& readShort (short &val) override;
+    const Reader& operator>> (short &val) override
+        { return readShort(val); }
+        
+    const Reader& readUnsignedShort (unsigned short &val) override;
+    const Reader& operator>> (unsigned short &val) override
+        { return readUnsignedShort(val); }
+        
+    const Reader& readInt (int &val) override;
+    const Reader& operator>> (int &val) override
+        { return readInt(val); }
+        
+    const Reader& readUnsignedInt (unsigned int &val) override;
+    const Reader& operator>> (unsigned int &val) override
+        { return readUnsignedInt(val); }
+        
+    const Reader& readLong (long &val) override;
+    const Reader& operator>> (long &val) override
+        { return readLong(val); }
+        
+    const Reader& readUnsignedLong (unsigned long &val) override;
+    const Reader& operator>> (unsigned long &val) override
+        { return readUnsignedLong(val); }
+        
+    const Reader& readFloat (float &val) override;
+    const Reader& operator>> (float &val) override
+        { return readFloat(val); }
+        
+    const Reader& readDouble (double &val) override;
+    const Reader& operator>> (double &val) override
+        { return readDouble(val); }
+ 
+
+protected:
+
+    Reader *source;
+
+    BasicReader()
+        { source = nullptr; }
+
+private:
+
+}; // class BasicReader
+
+
+
+/**
+ * Class for placing a Reader on an open InputStream
+ *
+ */
+class InputStreamReader : public BasicReader
+{
+public:
+
+    InputStreamReader(InputStream &inputStreamSource);
+    
+    /*Overload these 3 for your implementation*/
+    int available() override;
+    
+    void close() override;
+    
+    char get() override;
+
+
+private:
+
+    InputStream &inputStream;
+
+
+};
+
+/**
+ * Convenience class for reading formatted from standard input
+ *
+ */
+class StdReader : public BasicReader
+{
+public:
+
+    StdReader();
+
+    ~StdReader() override;
+    
+    /*Overload these 3 for your implementation*/
+    int available() override;
+    
+    void close() override;
+    
+    char get() override;
+
+
+private:
+
+    InputStream *inputStream;
+
+
+};
+
+
+
+
+
+//#########################################################################
+//# W R I T E R
+//#########################################################################
+
+/**
+ * This interface and its descendants are for unicode character-oriented output
+ *
+ */
+class Writer
+{
+
+public:
+
+    /**
+     * Constructor.
+     */
+    Writer() = default;
+
+    /**
+     * Destructor
+     */
+    virtual ~Writer() = default;
+
+    virtual void close() = 0;
+    
+    virtual void flush() = 0;
+    
+    virtual void put(char ch) = 0;
+    
+    /* Formatted output */
+    virtual Writer& printf(char const *fmt, ...) G_GNUC_PRINTF(2,3) = 0;
+
+    virtual Writer& writeChar(char val) = 0;
+
+    virtual Writer& writeUString(const Glib::ustring &val) = 0;
+
+    virtual Writer& writeStdString(const std::string &val) = 0;
+
+    virtual Writer& writeString(const char *str) = 0;
+
+    virtual Writer& writeBool (bool val ) = 0;
+
+    virtual Writer& writeShort (short val ) = 0;
+
+    virtual Writer& writeUnsignedShort (unsigned short val ) = 0;
+
+    virtual Writer& writeInt (int val ) = 0;
+
+    virtual Writer& writeUnsignedInt (unsigned int val ) = 0;
+
+    virtual Writer& writeLong (long val ) = 0;
+
+    virtual Writer& writeUnsignedLong (unsigned long val ) = 0;
+
+    virtual Writer& writeFloat (float val ) = 0;
+
+    virtual Writer& writeDouble (double val ) = 0;
+
+ 
+
+}; // interface Writer
+
+
+/**
+ * This class and its descendants are for unicode character-oriented output
+ *
+ */
+class BasicWriter : public Writer
+{
+
+public:
+
+    BasicWriter(Writer &destinationWriter);
+
+    ~BasicWriter() override = default;
+
+    /*Overload these 3 for your implementation*/
+    void close() override;
+    
+    void flush() override;
+    
+    void put(char ch) override;
+    
+    
+    
+    /* Formatted output */
+    Writer &printf(char const *fmt, ...) override G_GNUC_PRINTF(2,3);
+
+    Writer& writeChar(char val) override;
+
+    Writer& writeUString(const Glib::ustring &val) override;
+
+    Writer& writeStdString(const std::string &val) override;
+
+    Writer& writeString(const char *str) override;
+
+    Writer& writeBool (bool val ) override;
+
+    Writer& writeShort (short val ) override;
+
+    Writer& writeUnsignedShort (unsigned short val ) override;
+
+    Writer& writeInt (int val ) override;
+
+    Writer& writeUnsignedInt (unsigned int val ) override;
+
+    Writer& writeLong (long val ) override;
+
+    Writer& writeUnsignedLong (unsigned long val ) override;
+
+    Writer& writeFloat (float val ) override;
+
+    Writer& writeDouble (double val ) override;
+
+ 
+protected:
+
+    Writer *destination;
+
+    BasicWriter()
+        { destination = nullptr; }
+    
+private:
+
+}; // class BasicWriter
+
+
+
+Writer& operator<< (Writer &writer, char val);
+
+Writer& operator<< (Writer &writer, Glib::ustring &val);
+
+Writer& operator<< (Writer &writer, std::string &val);
+
+Writer& operator<< (Writer &writer, char const *val);
+
+Writer& operator<< (Writer &writer, bool val);
+
+Writer& operator<< (Writer &writer, short val);
+
+Writer& operator<< (Writer &writer, unsigned short val);
+
+Writer& operator<< (Writer &writer, int val);
+
+Writer& operator<< (Writer &writer, unsigned int val);
+
+Writer& operator<< (Writer &writer, long val);
+
+Writer& operator<< (Writer &writer, unsigned long val);
+
+Writer& operator<< (Writer &writer, float val);
+
+Writer& operator<< (Writer &writer, double val);
+
+
+
+
+/**
+ * Class for placing a Writer on an open OutputStream
+ *
+ */
+class OutputStreamWriter : public BasicWriter
+{
+public:
+
+    OutputStreamWriter(OutputStream &outputStreamDest);
+    
+    /*Overload these 3 for your implementation*/
+    void close() override;
+    
+    void flush() override;
+    
+    void put(char ch) override;
+
+
+private:
+
+    OutputStream &outputStream;
+
+
+};
+
+
+/**
+ * Convenience class for writing to standard output
+ */
+class StdWriter : public BasicWriter
+{
+public:
+    StdWriter();
+
+    ~StdWriter() override;
+
+
+    void close() override;
+
+    
+    void flush() override;
+
+    
+    void put(char ch) override;
+
+
+private:
+
+    OutputStream *outputStream;
+
+};
+
+//#########################################################################
+//# U T I L I T Y
+//#########################################################################
+
+void pipeStream(InputStream &source, OutputStream &dest);
+
+
+
+} // namespace IO
+} // namespace Inkscape
+
+
+#endif // SEEN_INKSCAPE_IO_INKSCAPESTREAM_H
diff --git a/src/io/stream/stringstream.cpp b/src/io/stream/stringstream.cpp
new file mode 100644
index 0000000..0259869
--- /dev/null
+++ b/src/io/stream/stringstream.cpp
@@ -0,0 +1,125 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Our base String stream classes.  We implement these to
+ * be based on Glib::ustring
+ *
+ * Authors:
+ *   Bob Jamison <rjamison@titan.com>
+ *
+ * Copyright (C) 2004 Inkscape.org
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+
+#include "stringstream.h"
+
+namespace Inkscape
+{
+namespace IO
+{
+
+
+//#########################################################################
+//# S T R I N G    I N P U T    S T R E A M
+//#########################################################################
+
+
+/**
+ *
+ */ 
+StringInputStream::StringInputStream(Glib::ustring &sourceString)
+                      : buffer(sourceString)
+{
+    position = 0;
+}
+
+/**
+ *
+ */ 
+StringInputStream::~StringInputStream()
+= default;
+
+/**
+ * Returns the number of bytes that can be read (or skipped over) from
+ * this input stream without blocking by the next caller of a method for
+ * this input stream.
+ */ 
+int StringInputStream::available()
+{
+    return buffer.size() - position;
+}
+
+    
+/**
+ *  Closes this input stream and releases any system resources
+ *  associated with the stream.
+ */ 
+void StringInputStream::close()
+{
+}
+    
+/**
+ * Reads the next byte of data from the input stream.  -1 if EOF
+ */ 
+int StringInputStream::get()
+{
+    if (position >= (int)buffer.size())
+        return -1;
+    int ch = (int) buffer[position++];
+    return ch;
+}
+   
+
+
+
+//#########################################################################
+//# S T R I N G     O U T P U T    S T R E A M
+//#########################################################################
+
+/**
+ *
+ */ 
+StringOutputStream::StringOutputStream()
+= default;
+
+/**
+ *
+ */ 
+StringOutputStream::~StringOutputStream()
+= default;
+
+/**
+ * Closes this output stream and releases any system resources
+ * associated with this stream.
+ */ 
+void StringOutputStream::close()
+{
+}
+    
+/**
+ *  Flushes this output stream and forces any buffered output
+ *  bytes to be written out.
+ */ 
+void StringOutputStream::flush()
+{
+    //nothing to do
+}
+    
+/**
+ * Writes the specified byte to this output stream.
+ */ 
+int StringOutputStream::put(char ch)
+{
+    buffer.push_back(ch);
+	return 1;
+}
+
+
+} // namespace IO
+} // namespace Inkscape
+
+
+//#########################################################################
+//# E N D    O F    F I L E
+//#########################################################################
diff --git a/src/io/stream/stringstream.h b/src/io/stream/stringstream.h
new file mode 100644
index 0000000..3afb9a8
--- /dev/null
+++ b/src/io/stream/stringstream.h
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/** @file
+ * TODO: insert short description here
+ *//*
+ * Authors: see git history
+ *
+ * Copyright (C) 2018 Authors
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+#ifndef __INKSCAPE_IO_STRINGSTREAM_H__
+#define __INKSCAPE_IO_STRINGSTREAM_H__
+
+#include <glibmm/ustring.h>
+
+#include "inkscapestream.h"
+
+
+namespace Inkscape
+{
+namespace IO
+{
+
+
+//#########################################################################
+//# S T R I N G    I N P U T    S T R E A M
+//#########################################################################
+
+/**
+ * This class is for reading character from a Glib::ustring
+ *
+ */
+class StringInputStream : public InputStream
+{
+
+public:
+
+    StringInputStream(Glib::ustring &sourceString);
+    
+    ~StringInputStream() override;
+    
+    int available() override;
+    
+    void close() override;
+    
+    int get() override;
+    
+private:
+
+    Glib::ustring &buffer;
+
+    long position;
+
+}; // class StringInputStream
+
+
+
+
+//#########################################################################
+//# S T R I N G   O U T P U T    S T R E A M
+//#########################################################################
+
+/**
+ * This class is for sending a stream to a Glib::ustring
+ *
+ */
+class StringOutputStream : public OutputStream
+{
+
+public:
+
+    StringOutputStream();
+    
+    ~StringOutputStream() override;
+    
+    void close() override;
+    
+    void flush() override;
+    
+    int put(char ch) override;
+
+    virtual Glib::ustring &getString()
+        { return buffer; }
+
+    virtual void clear()
+        { buffer = ""; }
+
+private:
+
+    Glib::ustring buffer;
+
+
+}; // class StringOutputStream
+
+
+
+
+
+
+
+} // namespace IO
+} // namespace Inkscape
+
+
+
+#endif /* __INKSCAPE_IO_STRINGSTREAM_H__ */
diff --git a/src/io/stream/uristream.cpp b/src/io/stream/uristream.cpp
new file mode 100644
index 0000000..734b8fa
--- /dev/null
+++ b/src/io/stream/uristream.cpp
@@ -0,0 +1,171 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Our base String stream classes.  We implement these to
+ * be based on Glib::ustring
+ *
+ * Authors:
+ *   Bob Jamison <rjamison@titan.com>
+ *
+ * Copyright (C) 2004 Inkscape.org
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+
+#include "uristream.h"
+#include "io/sys.h"
+
+
+namespace Inkscape
+{
+namespace IO
+{
+
+//#########################################################################
+//# F I L E    I N P U T    S T R E A M
+//#########################################################################
+
+
+/**
+ *
+ */
+FileInputStream::FileInputStream(FILE *source)
+    : inf(source)
+{
+    if (!inf) {
+        Glib::ustring err = "FileInputStream passed NULL";
+        throw StreamException(err);
+    }
+}
+
+/**
+ *
+ */
+FileInputStream::~FileInputStream()
+{
+    close();
+}
+
+/**
+ * Returns the number of bytes that can be read (or skipped over) from
+ * this input stream without blocking by the next caller of a method for
+ * this input stream.
+ */
+int FileInputStream::available()
+{
+    return 0;
+}
+
+
+/**
+ *  Closes this input stream and releases any system resources
+ *  associated with the stream.
+ */
+void FileInputStream::close()
+{
+            if (!inf)
+                return;
+            fflush(inf);
+            fclose(inf);
+            inf=nullptr;
+}
+
+/**
+ * Reads the next byte of data from the input stream.  -1 if EOF
+ */
+int FileInputStream::get()
+{
+    int retVal = -1;
+                if (!inf || feof(inf))
+                {
+                    retVal = -1;
+                }
+                else
+                {
+                    retVal = fgetc(inf);
+                }
+
+    return retVal;
+}
+
+
+
+
+//#########################################################################
+//#  F I L E    O U T P U T    S T R E A M
+//#########################################################################
+
+FileOutputStream::FileOutputStream(FILE *fp)
+    : ownsFile(false)
+    , outf(fp)
+{
+    if (!outf) {
+        Glib::ustring err = "FileOutputStream given null file ";
+        throw StreamException(err);
+    }
+}
+
+/**
+ *
+ */
+FileOutputStream::~FileOutputStream()
+{
+    close();
+}
+
+/**
+ * Closes this output stream and releases any system resources
+ * associated with this stream.
+ */
+void FileOutputStream::close()
+{
+            if (!outf)
+                return;
+            fflush(outf);
+            if ( ownsFile )
+                fclose(outf);
+            outf=nullptr;
+}
+
+/**
+ *  Flushes this output stream and forces any buffered output
+ *  bytes to be written out.
+ */
+void FileOutputStream::flush()
+{
+            if (!outf)
+                return;
+            fflush(outf);
+}
+
+/**
+ * Writes the specified byte to this output stream.
+ */
+int FileOutputStream::put(char ch)
+{
+    unsigned char uch;
+
+            if (!outf)
+                return -1;
+            uch = (unsigned char)(ch & 0xff);
+            if (fputc(uch, outf) == EOF) {
+                Glib::ustring err = "ERROR writing to file ";
+                throw StreamException(err);
+            }
+
+    return 1;
+}
+
+
+
+
+
+} // namespace IO
+} // namespace Inkscape
+
+
+//#########################################################################
+//# E N D    O F    F I L E
+//#########################################################################
+
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/io/stream/uristream.h b/src/io/stream/uristream.h
new file mode 100644
index 0000000..f0544d8
--- /dev/null
+++ b/src/io/stream/uristream.h
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_INKSCAPE_IO_URISTREAM_H
+#define SEEN_INKSCAPE_IO_URISTREAM_H
+/**
+ * @file
+ * This should be the only way that we provide sources/sinks
+ * to any input/output stream.
+ */
+/*
+ * Authors:
+ *   Bob Jamison <rjamison@titan.com>
+ *
+ * Copyright (C) 2004 Inkscape.org
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+
+#include "object/uri.h"
+
+#include "inkscapestream.h"
+
+
+namespace Inkscape
+{
+
+class URI;
+
+namespace IO
+{
+
+//#########################################################################
+//# F I L E    I N P U T    S T R E A M
+//#########################################################################
+
+/**
+ * This class is for receiving a stream of data from a file
+ */
+class FileInputStream : public InputStream
+{
+
+public:
+    FileInputStream(FILE *source);
+
+    ~FileInputStream() override;
+
+    int available() override;
+
+    void close() override;
+
+    int get() override;
+
+private:
+    FILE *inf;           //for file: uris
+
+}; // class FileInputStream
+
+
+
+
+//#########################################################################
+//# F I L E    O U T P U T    S T R E A M
+//#########################################################################
+
+/**
+ * This class is for sending a stream to a destination file
+ */
+class FileOutputStream : public OutputStream
+{
+
+public:
+
+    FileOutputStream(FILE *fp);
+
+    ~FileOutputStream() override;
+
+    void close() override;
+
+    void flush() override;
+
+    int put(char ch) override;
+
+private:
+
+    bool ownsFile;
+
+    FILE *outf;         //for file: uris
+
+}; // class FileOutputStream
+
+
+
+
+
+} // namespace IO
+} // namespace Inkscape
+
+
+#endif // SEEN_INKSCAPE_IO_URISTREAM_H
+
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
diff --git a/src/io/stream/xsltstream.cpp b/src/io/stream/xsltstream.cpp
new file mode 100644
index 0000000..882db30
--- /dev/null
+++ b/src/io/stream/xsltstream.cpp
@@ -0,0 +1,248 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * XSL Transforming input and output classes
+ *
+ * Authors:
+ *   Bob Jamison <ishmalius@gmail.com>
+ *
+ * Copyright (C) 2004-2008 Inkscape.org
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+
+#include "xsltstream.h"
+#include "stringstream.h"
+#include <libxslt/transform.h>
+
+
+
+
+namespace Inkscape
+{
+namespace IO
+{
+
+//#########################################################################
+//# X S L T    S T Y L E S H E E T
+//#########################################################################
+
+/**
+ *
+ */
+XsltStyleSheet::XsltStyleSheet(InputStream &xsltSource)
+              
+                   : stylesheet(nullptr)
+{
+    if (!read(xsltSource)) {
+        throw StreamException("read failed");
+        }
+}
+
+/**
+ *
+ */
+XsltStyleSheet::XsltStyleSheet()
+                    : stylesheet(nullptr)
+{
+}
+
+
+
+/**
+ *
+ */
+bool XsltStyleSheet::read(InputStream &xsltSource)
+{
+    StringOutputStream outs;
+    pipeStream(xsltSource, outs);
+    std::string strBuf = outs.getString().raw();
+    xmlDocPtr doc = xmlParseMemory(strBuf.c_str(), strBuf.size());
+    stylesheet = xsltParseStylesheetDoc(doc);
+    //following not necessary.  handled by xsltFreeStylesheet(stylesheet);
+    //xmlFreeDoc(doc);
+    if (!stylesheet)
+        return false;
+    return true;
+}
+
+
+/**
+ *
+ */ 
+XsltStyleSheet::~XsltStyleSheet()
+{
+    if (stylesheet)
+        xsltFreeStylesheet(stylesheet);
+}
+
+
+
+//#########################################################################
+//# X S L T    I N P U T    S T R E A M
+//#########################################################################
+
+
+/**
+ *
+ */ 
+XsltInputStream::XsltInputStream(InputStream &xmlSource, XsltStyleSheet &sheet)
+                        : BasicInputStream(xmlSource), stylesheet(sheet)
+{
+    //Load the data
+    StringOutputStream outs;
+    pipeStream(source, outs);
+    std::string strBuf = outs.getString().raw();
+    
+    //Do the processing
+    const char *params[1];
+    params[0] = nullptr;
+    xmlDocPtr srcDoc = xmlParseMemory(strBuf.c_str(), strBuf.size());
+    xmlDocPtr resDoc = xsltApplyStylesheet(stylesheet.stylesheet, srcDoc, params);
+    xmlDocDumpFormatMemory(resDoc, &outbuf, &outsize, 1);
+    outpos = 0;
+        
+    //Free our mem
+    xmlFreeDoc(resDoc);
+    xmlFreeDoc(srcDoc);
+}
+
+/**
+ *
+ */ 
+XsltInputStream::~XsltInputStream()
+{
+    xmlFree(outbuf);
+}
+
+/**
+ * Returns the number of bytes that can be read (or skipped over) from
+ * this input stream without blocking by the next caller of a method for
+ * this input stream.
+ */ 
+int XsltInputStream::available()
+{
+    return outsize - outpos;
+}
+
+    
+/**
+ *  Closes this input stream and releases any system resources
+ *  associated with the stream.
+ */ 
+void XsltInputStream::close()
+{
+    closed = true;
+}
+    
+/**
+ * Reads the next byte of data from the input stream.  -1 if EOF
+ */ 
+int XsltInputStream::get()
+{
+    if (closed)
+        return -1;
+    if (outpos >= outsize)
+        return -1;
+    int ch = (int) outbuf[outpos++];
+    return ch;
+}
+   
+
+
+
+
+
+//#########################################################################
+//#  X S L T     O U T P U T    S T R E A M
+//#########################################################################
+
+/**
+ *
+ */ 
+XsltOutputStream::XsltOutputStream(OutputStream &dest, XsltStyleSheet &sheet)
+                     : BasicOutputStream(dest), stylesheet(sheet)
+{
+    flushed = false;
+}
+
+/**
+ *
+ */ 
+XsltOutputStream::~XsltOutputStream()
+{
+    //do not automatically close
+}
+
+/**
+ * Closes this output stream and releases any system resources
+ * associated with this stream.
+ */ 
+void XsltOutputStream::close()
+{
+    flush();
+    destination.close();
+}
+    
+/**
+ *  Flushes this output stream and forces any buffered output
+ *  bytes to be written out.
+ */ 
+void XsltOutputStream::flush()
+{
+    if (flushed)
+        {
+        destination.flush();
+        return;
+        }
+        
+    //Do the processing
+    xmlChar *resbuf;
+    int resSize;
+    const char *params[1];
+    params[0] = nullptr;
+    xmlDocPtr srcDoc = xmlParseMemory(outbuf.raw().c_str(), outbuf.size());
+    xmlDocPtr resDoc = xsltApplyStylesheet(stylesheet.stylesheet, srcDoc, params);
+    xmlDocDumpFormatMemory(resDoc, &resbuf, &resSize, 1);
+    /*
+    xmlErrorPtr err = xmlGetLastError();
+    if (err)
+        {
+        throw StreamException(err->message);
+        }
+    */
+
+    for (int i=0 ; i<resSize ; i++)
+        {
+        char ch = resbuf[i];
+        destination.put(ch);
+        }
+        
+    //Free our mem
+    xmlFree(resbuf);
+    xmlFreeDoc(resDoc);
+    xmlFreeDoc(srcDoc);
+    destination.flush();
+    flushed = true;
+}
+    
+/**
+ * Writes the specified byte to this output stream.
+ */ 
+int XsltOutputStream::put(char ch)
+{
+    outbuf.push_back(ch);
+	return 1;
+}
+
+
+
+
+
+} // namespace IO
+} // namespace Inkscape
+
+
+//#########################################################################
+//# E N D    O F    F I L E
+//#########################################################################
diff --git a/src/io/stream/xsltstream.h b/src/io/stream/xsltstream.h
new file mode 100644
index 0000000..7410ddc
--- /dev/null
+++ b/src/io/stream/xsltstream.h
@@ -0,0 +1,140 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_INKSCAPE_IO_XSLTSTREAM_H
+#define SEEN_INKSCAPE_IO_XSLTSTREAM_H
+/**
+ * @file
+ * Xslt-enabled input and output streams.
+ */
+/*
+ * Authors:
+ *   Bob Jamison <ishmalius@gmail.com>
+ *
+ * Copyright (C) 2004-2008 Inkscape.org
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+
+#include "inkscapestream.h"
+
+#include <libxslt/xslt.h>
+#include <libxslt/xsltInternals.h>
+
+
+namespace Inkscape
+{
+namespace IO
+{
+
+//#########################################################################
+//# X S L T    S T Y L E S H E E T
+//#########################################################################
+/**
+ * This is a container for reusing a loaded stylesheet
+ */
+class XsltStyleSheet
+{
+
+public:
+
+    /**
+     * Constructor with loading
+     */
+    XsltStyleSheet(InputStream &source);
+
+    /**
+     * Simple constructor, no loading
+     */
+    XsltStyleSheet();
+
+    /**
+     * Loader
+     */
+    bool read(InputStream &source);
+
+    /**
+     * Destructor
+     */
+    virtual ~XsltStyleSheet();
+    
+    xsltStylesheetPtr stylesheet;
+
+
+}; // class XsltStyleSheet
+
+
+//#########################################################################
+//# X S L T    I N P U T    S T R E A M
+//#########################################################################
+
+/**
+ * This class is for transforming stream input by a given stylesheet
+ */
+class XsltInputStream : public BasicInputStream
+{
+
+public:
+
+    XsltInputStream(InputStream &xmlSource, XsltStyleSheet &stylesheet);
+    
+    ~XsltInputStream() override;
+    
+    int available() override;
+    
+    void close() override;
+    
+    int get() override;
+    
+
+private:
+
+    XsltStyleSheet &stylesheet;
+
+    xmlChar *outbuf;
+    int outsize;
+    int outpos;
+
+}; // class XsltInputStream
+
+
+
+
+//#########################################################################
+//# X S L T    O U T P U T    S T R E A M
+//#########################################################################
+
+/**
+ * This class is for transforming stream output by a given stylesheet
+ */
+class XsltOutputStream : public BasicOutputStream
+{
+
+public:
+
+    XsltOutputStream(OutputStream &destination, XsltStyleSheet &stylesheet);
+    
+    ~XsltOutputStream() override;
+    
+    void close() override;
+    
+    void flush() override;
+    
+    int put(char ch) override;
+
+private:
+
+    XsltStyleSheet &stylesheet;
+
+    Glib::ustring outbuf;
+    
+    bool flushed;
+
+}; // class XsltOutputStream
+
+
+
+} // namespace IO
+} // namespace Inkscape
+
+
+#endif /* __INKSCAPE_IO_XSLTSTREAM_H__ */
diff --git a/src/io/sys.cpp b/src/io/sys.cpp
new file mode 100644
index 0000000..b06c638
--- /dev/null
+++ b/src/io/sys.cpp
@@ -0,0 +1,360 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+/*
+ * System abstraction utility routines
+ *
+ * Authors:
+ *   Jon A. Cruz <jon@joncruz.org>
+ *
+ * Copyright (C) 2004-2005 Authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+
+#include <fstream>
+#ifdef _WIN32
+#include <fcntl.h>
+#include <io.h>
+#endif
+
+#include <glib.h>
+#include <glib/gstdio.h>
+#include <glibmm/ustring.h>
+
+#include "preferences.h"
+#include "sys.h"
+
+//#define INK_DUMP_FILENAME_CONV 1
+#undef INK_DUMP_FILENAME_CONV
+
+//#define INK_DUMP_FOPEN 1
+#undef INK_DUMP_FOPEN
+
+void dump_str(gchar const *str, gchar const *prefix);
+void dump_ustr(Glib::ustring const &ustr);
+
+extern guint update_in_progress;
+
+
+void Inkscape::IO::dump_fopen_call( char const *utf8name, char const *id )
+{
+#ifdef INK_DUMP_FOPEN
+    Glib::ustring str;
+    for ( int i = 0; utf8name[i]; i++ )
+    {
+        if ( utf8name[i] == '\\' )
+        {
+            str += "\\\\";
+        }
+        else if ( (utf8name[i] >= 0x20) && ((0x0ff & utf8name[i]) <= 0x7f) )
+        {
+            str += utf8name[i];
+        }
+        else
+        {
+            gchar tmp[32];
+            g_snprintf( tmp, sizeof(tmp), "\\x%02x", (0x0ff & utf8name[i]) );
+            str += tmp;
+        }
+    }
+    g_message( "fopen call %s for [%s]", id, str.data() );
+#else
+    (void)utf8name;
+    (void)id;
+#endif
+}
+
+FILE *Inkscape::IO::fopen_utf8name( char const *utf8name, char const *mode )
+{
+    FILE* fp = nullptr;
+
+    if (Glib::ustring( utf8name ) == Glib::ustring("-")) {
+        // user requests to use pipes
+
+        Glib::ustring how( mode );
+        if ( how.find("w") != Glib::ustring::npos ) {
+#ifdef _WIN32
+            setmode(fileno(stdout), O_BINARY);
+#endif
+            return stdout;
+        } else {
+            return stdin;
+        }
+    }
+
+    gchar *filename = g_filename_from_utf8( utf8name, -1, nullptr, nullptr, nullptr );
+    if ( filename )
+    {
+        // ensure we open the file in binary mode (not needed in POSIX but doesn't hurt either)
+        Glib::ustring how( mode );
+        if ( how.find("b") == Glib::ustring::npos )
+        {
+            how.append("b");
+        }
+        // when opening a file for writing: create parent directories if they don't exist already
+        if ( how.find("w") != Glib::ustring::npos )
+        {
+            gchar *dirname = g_path_get_dirname(utf8name);
+            if (g_mkdir_with_parents(dirname, 0777)) {
+                g_warning("Could not create directory '%s'", dirname);
+            }
+            g_free(dirname);
+        }
+        fp = g_fopen(filename, how.c_str());
+        g_free(filename);
+        filename = nullptr;
+    }
+    return fp;
+}
+
+
+int Inkscape::IO::mkdir_utf8name( char const *utf8name )
+{
+    int retval = -1;
+    gchar *filename = g_filename_from_utf8( utf8name, -1, nullptr, nullptr, nullptr );
+    if ( filename )
+    {
+        retval = g_mkdir(filename, S_IRWXU | S_IRGRP | S_IXGRP); // The mode argument is ignored on Windows.
+        g_free(filename);
+        filename = nullptr;
+    }
+    return retval;
+}
+
+bool Inkscape::IO::file_test( char const *utf8name, GFileTest test )
+{
+    bool exists = false;
+
+    // in case the file to check is a pipe it doesn't need to exist
+    if (g_strcmp0(utf8name, "-") == 0 && G_FILE_TEST_IS_REGULAR)
+        return true;
+
+    if ( utf8name ) {
+        gchar *filename = nullptr;
+        if (utf8name && !g_utf8_validate(utf8name, -1, nullptr)) {
+            /* FIXME: Trying to guess whether or not a filename is already in utf8 is unreliable.
+               If any callers pass non-utf8 data (e.g. using g_get_home_dir), then change caller to
+               use simple g_file_test.  Then add g_return_val_if_fail(g_utf_validate(...), false)
+               to beginning of this function. */
+            filename = g_strdup(utf8name);
+            // Looks like g_get_home_dir isn't safe.
+            //g_warning("invalid UTF-8 detected internally. HUNT IT DOWN AND KILL IT!!!");
+        } else {
+            filename = g_filename_from_utf8 ( utf8name, -1, nullptr, nullptr, nullptr );
+        }
+        if ( filename ) {
+            exists = g_file_test (filename, test);
+            g_free(filename);
+            filename = nullptr;
+        } else {
+            g_warning( "Unable to convert filename in IO:file_test" );
+        }
+    }
+
+    return exists;
+}
+
+bool Inkscape::IO::file_is_writable( char const *utf8name)
+{
+    bool success = true;
+
+    if ( utf8name) {
+        gchar *filename = nullptr;
+        if (utf8name && !g_utf8_validate(utf8name, -1, nullptr)) {
+            /* FIXME: Trying to guess whether or not a filename is already in utf8 is unreliable.
+               If any callers pass non-utf8 data (e.g. using g_get_home_dir), then change caller to
+               use simple g_file_test.  Then add g_return_val_if_fail(g_utf_validate(...), false)
+               to beginning of this function. */
+            filename = g_strdup(utf8name);
+            // Looks like g_get_home_dir isn't safe.
+            //g_warning("invalid UTF-8 detected internally. HUNT IT DOWN AND KILL IT!!!");
+        } else {
+            filename = g_filename_from_utf8 ( utf8name, -1, nullptr, nullptr, nullptr );
+        }
+        if ( filename ) {
+            GStatBuf st;
+            if (g_file_test (filename, G_FILE_TEST_EXISTS)){ 
+                if (g_lstat (filename, &st) == 0) {
+                    success = ((st.st_mode & S_IWRITE) != 0);
+                }
+            }
+            g_free(filename);
+            filename = nullptr;
+        } else {
+            g_warning( "Unable to convert filename in IO:file_test" );
+        }
+    }
+
+    return success;
+}
+
+/**Checks if directory of file exists, useful
+ * because inkscape doesn't create directories.*/
+bool Inkscape::IO::file_directory_exists( char const *utf8name ){
+    bool exists = true;
+
+    if ( utf8name) {
+        gchar *filename = nullptr;
+        if (utf8name && !g_utf8_validate(utf8name, -1, nullptr)) {
+            /* FIXME: Trying to guess whether or not a filename is already in utf8 is unreliable.
+               If any callers pass non-utf8 data (e.g. using g_get_home_dir), then change caller to
+               use simple g_file_test.  Then add g_return_val_if_fail(g_utf_validate(...), false)
+               to beginning of this function. */
+            filename = g_strdup(utf8name);
+            // Looks like g_get_home_dir isn't safe.
+            //g_warning("invalid UTF-8 detected internally. HUNT IT DOWN AND KILL IT!!!");
+        } else {
+            filename = g_filename_from_utf8 ( utf8name, -1, nullptr, nullptr, nullptr );
+        }
+        if ( filename ) {
+            gchar *dirname = g_path_get_dirname(filename);
+            exists = Inkscape::IO::file_test( dirname, G_FILE_TEST_EXISTS);
+            g_free(filename);
+            g_free(dirname);
+            filename = nullptr;
+            dirname = nullptr;
+        } else {
+            g_warning( "Unable to convert filename in IO:file_test" );
+        }
+    }
+
+    return exists;
+
+}
+
+/** Wrapper around g_dir_open, but taking a utf8name as first argument. */
+GDir *
+Inkscape::IO::dir_open(gchar const *const utf8name, guint const flags, GError **const error)
+{
+    gchar *const opsys_name = g_filename_from_utf8(utf8name, -1, nullptr, nullptr, error);
+    if (opsys_name) {
+        GDir *ret = g_dir_open(opsys_name, flags, error);
+        g_free(opsys_name);
+        return ret;
+    } else {
+        return nullptr;
+    }
+}
+
+/**
+ * Like g_dir_read_name, but returns a utf8name (which must be freed, unlike g_dir_read_name).
+ *
+ * N.B. Skips over any dir entries that fail to convert to utf8.
+ */
+gchar *
+Inkscape::IO::dir_read_utf8name(GDir *dir)
+{
+    for (;;) {
+        gchar const *const opsys_name = g_dir_read_name(dir);
+        if (!opsys_name) {
+            return nullptr;
+        }
+        gchar *utf8_name = g_filename_to_utf8(opsys_name, -1, nullptr, nullptr, nullptr);
+        if (utf8_name) {
+            return utf8_name;
+        }
+    }
+}
+
+
+gchar* Inkscape::IO::locale_to_utf8_fallback( const gchar *opsysstring,
+                                              gssize len,
+                                              gsize *bytes_read,
+                                              gsize *bytes_written,
+                                              GError **error )
+{
+    gchar *result = nullptr;
+    if ( opsysstring ) {
+        gchar *newFileName = g_locale_to_utf8( opsysstring, len, bytes_read, bytes_written, error );
+        if ( newFileName ) {
+            if ( !g_utf8_validate(newFileName, -1, nullptr) ) {
+                g_warning( "input filename did not yield UTF-8" );
+                g_free( newFileName );
+            } else {
+                result = newFileName;
+            }
+            newFileName = nullptr;
+        } else if ( g_utf8_validate(opsysstring, -1, nullptr) ) {
+            // This *might* be a case that we want
+            // g_warning( "input failed filename->utf8, fell back to original" );
+            // TODO handle cases when len >= 0
+            result = g_strdup( opsysstring );
+        } else {
+            gchar const *charset = nullptr;
+            g_get_charset(&charset);
+            g_warning( "input filename conversion failed for file with locale charset '%s'", charset );
+        }
+    }
+    return result;
+}
+
+void
+Inkscape::IO::spawn_async_with_pipes( const std::string& working_directory,
+                                      const std::vector<std::string>& argv,
+                                      Glib::SpawnFlags flags,
+                                      const sigc::slot<void ()>& child_setup,
+                                      Glib::Pid* child_pid,
+                                      int* standard_input,
+                                      int* standard_output,
+                                      int* standard_error)
+{
+    Glib::spawn_async_with_pipes(working_directory,
+                                 argv,
+                                 flags,
+                                 child_setup,
+                                 child_pid,
+                                 standard_input,
+                                 standard_output,
+                                 standard_error);
+}
+
+
+gchar* Inkscape::IO::sanitizeString( gchar const * str )
+{
+    gchar *result = nullptr;
+    if ( str ) {
+        if ( g_utf8_validate(str, -1, nullptr) ) {
+            result = g_strdup(str);
+        } else {
+            guchar scratch[8];
+            Glib::ustring buf;
+            guchar const *ptr = (guchar const*)str;
+            while ( *ptr )
+            {
+                if ( *ptr == '\\' )
+                {
+                    buf.append("\\\\");
+                } else if ( *ptr < 0x80 ) {
+                    buf += (char)(*ptr);
+                } else {
+                    g_snprintf((gchar*)scratch, sizeof(scratch), "\\x%02x", *ptr);
+                    buf.append((const char*)scratch);
+                }
+                ptr++;
+            }
+            result = g_strdup(buf.c_str());
+        }
+    }
+    return result;
+}
+
+/* 
+ * Returns the file extension of a path/filename
+ */
+Glib::ustring Inkscape::IO::get_file_extension(Glib::ustring path)
+{
+    Glib::ustring::size_type loc = path.find_last_of(".");
+    return loc < path.size() ? path.substr(loc) : "";
+}
+
+/*
+  Local Variables:
+  mode:c++
+  c-file-style:"stroustrup"
+  c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
+  indent-tabs-mode:nil
+  fill-column:99
+  End:
+*/
+// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4 :
diff --git a/src/io/sys.h b/src/io/sys.h
new file mode 100644
index 0000000..f2a7e1e
--- /dev/null
+++ b/src/io/sys.h
@@ -0,0 +1,70 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#ifndef SEEN_SYS_H
+#define SEEN_SYS_H
+
+/*
+ * System abstraction utility routines
+ *
+ * Authors:
+ *   Jon A. Cruz <jon@joncruz.org>
+ *
+ * Copyright (C) 2004-2005 Authors
+ *
+ * Released under GNU GPL v2+, read the file 'COPYING' for more information.
+ */
+
+#include <cstdio>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <glib.h>
+#include <glibmm/spawn.h>
+#include <string>
+#include <vector>
+
+/*#####################
+## U T I L I T Y
+#####################*/
+
+namespace Inkscape {
+namespace IO {
+
+void dump_fopen_call( char const *utf8name, char const *id );
+
+FILE *fopen_utf8name( char const *utf8name, char const *mode );
+
+int mkdir_utf8name( char const *utf8name );
+
+bool file_test( char const *utf8name, GFileTest test );
+
+bool file_directory_exists( char const *utf8name );
+
+bool file_is_writable( char const *utf8name);
+
+GDir *dir_open(gchar const *utf8name, guint flags, GError **error);
+
+gchar *dir_read_utf8name(GDir *dir);
+
+gchar* locale_to_utf8_fallback( const gchar *opsysstring,
+				gssize len,
+				gsize *bytes_read,
+				gsize *bytes_written,
+				GError **error );
+
+gchar* sanitizeString( gchar const * str );
+
+void spawn_async_with_pipes (const std::string& working_directory,
+                             const std::vector<std::string>& argv,
+                             Glib::SpawnFlags flags,
+                             const sigc::slot<void ()>& child_setup,
+                             Glib::Pid* child_pid,
+                             int* standard_input,
+                             int* standard_output,
+                             int* standard_error);
+
+Glib::ustring get_file_extension(Glib::ustring path);
+
+}
+}
+
+
+#endif // SEEN_SYS_H