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-rw-r--r--src/xz/suffix.c411
1 files changed, 411 insertions, 0 deletions
diff --git a/src/xz/suffix.c b/src/xz/suffix.c
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+++ b/src/xz/suffix.c
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+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file suffix.c
+/// \brief Checks filename suffix and creates the destination filename
+//
+// Author: Lasse Collin
+//
+// This file has been put into the public domain.
+// You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "private.h"
+
+#ifdef __DJGPP__
+# include <fcntl.h>
+#endif
+
+// For case-insensitive filename suffix on case-insensitive systems
+#if defined(TUKLIB_DOSLIKE) || defined(__VMS)
+# ifdef HAVE_STRINGS_H
+# include <strings.h>
+# endif
+# define strcmp strcasecmp
+#endif
+
+
+static char *custom_suffix = NULL;
+
+
+/// \brief Test if the char is a directory separator
+static bool
+is_dir_sep(char c)
+{
+#ifdef TUKLIB_DOSLIKE
+ return c == '/' || c == '\\' || c == ':';
+#else
+ return c == '/';
+#endif
+}
+
+
+/// \brief Test if the string contains a directory separator
+static bool
+has_dir_sep(const char *str)
+{
+#ifdef TUKLIB_DOSLIKE
+ return strpbrk(str, "/\\:") != NULL;
+#else
+ return strchr(str, '/') != NULL;
+#endif
+}
+
+
+#ifdef __DJGPP__
+/// \brief Test for special suffix used for 8.3 short filenames (SFN)
+///
+/// \return If str matches *.?- or *.??-, true is returned. Otherwise
+/// false is returned.
+static bool
+has_sfn_suffix(const char *str, size_t len)
+{
+ if (len >= 4 && str[len - 1] == '-' && str[len - 2] != '.'
+ && !is_dir_sep(str[len - 2])) {
+ // *.?-
+ if (str[len - 3] == '.')
+ return !is_dir_sep(str[len - 4]);
+
+ // *.??-
+ if (len >= 5 && !is_dir_sep(str[len - 3])
+ && str[len - 4] == '.')
+ return !is_dir_sep(str[len - 5]);
+ }
+
+ return false;
+}
+#endif
+
+
+/// \brief Checks if src_name has given compressed_suffix
+///
+/// \param suffix Filename suffix to look for
+/// \param src_name Input filename
+/// \param src_len strlen(src_name)
+///
+/// \return If src_name has the suffix, src_len - strlen(suffix) is
+/// returned. It's always a positive integer. Otherwise zero
+/// is returned.
+static size_t
+test_suffix(const char *suffix, const char *src_name, size_t src_len)
+{
+ const size_t suffix_len = strlen(suffix);
+
+ // The filename must have at least one character in addition to
+ // the suffix. src_name may contain path to the filename, so we
+ // need to check for directory separator too.
+ if (src_len <= suffix_len
+ || is_dir_sep(src_name[src_len - suffix_len - 1]))
+ return 0;
+
+ if (strcmp(suffix, src_name + src_len - suffix_len) == 0)
+ return src_len - suffix_len;
+
+ return 0;
+}
+
+
+/// \brief Removes the filename suffix of the compressed file
+///
+/// \return Name of the uncompressed file, or NULL if file has unknown
+/// suffix.
+static char *
+uncompressed_name(const char *src_name, const size_t src_len)
+{
+ static const struct {
+ const char *compressed;
+ const char *uncompressed;
+ } suffixes[] = {
+ { ".xz", "" },
+ { ".txz", ".tar" }, // .txz abbreviation for .txt.gz is rare.
+ { ".lzma", "" },
+#ifdef __DJGPP__
+ { ".lzm", "" },
+#endif
+ { ".tlz", ".tar" }, // Both .tar.lzma and .tar.lz
+#ifdef HAVE_LZIP_DECODER
+ { ".lz", "" },
+#endif
+ };
+
+ const char *new_suffix = "";
+ size_t new_len = 0;
+
+ if (opt_format == FORMAT_RAW) {
+ // Don't check for known suffixes when --format=raw was used.
+ if (custom_suffix == NULL) {
+ message_error(_("%s: With --format=raw, "
+ "--suffix=.SUF is required unless "
+ "writing to stdout"), src_name);
+ return NULL;
+ }
+ } else {
+ for (size_t i = 0; i < ARRAY_SIZE(suffixes); ++i) {
+ new_len = test_suffix(suffixes[i].compressed,
+ src_name, src_len);
+ if (new_len != 0) {
+ new_suffix = suffixes[i].uncompressed;
+ break;
+ }
+ }
+
+#ifdef __DJGPP__
+ // Support also *.?- -> *.? and *.??- -> *.?? on DOS.
+ // This is done also when long filenames are available
+ // to keep it easy to decompress files created when
+ // long filename support wasn't available.
+ if (new_len == 0 && has_sfn_suffix(src_name, src_len)) {
+ new_suffix = "";
+ new_len = src_len - 1;
+ }
+#endif
+ }
+
+ if (new_len == 0 && custom_suffix != NULL)
+ new_len = test_suffix(custom_suffix, src_name, src_len);
+
+ if (new_len == 0) {
+ message_warning(_("%s: Filename has an unknown suffix, "
+ "skipping"), src_name);
+ return NULL;
+ }
+
+ const size_t new_suffix_len = strlen(new_suffix);
+ char *dest_name = xmalloc(new_len + new_suffix_len + 1);
+
+ memcpy(dest_name, src_name, new_len);
+ memcpy(dest_name + new_len, new_suffix, new_suffix_len);
+ dest_name[new_len + new_suffix_len] = '\0';
+
+ return dest_name;
+}
+
+
+/// This message is needed in multiple places in compressed_name(),
+/// so the message has been put into its own function.
+static void
+msg_suffix(const char *src_name, const char *suffix)
+{
+ message_warning(_("%s: File already has `%s' suffix, skipping"),
+ src_name, suffix);
+ return;
+}
+
+
+/// \brief Appends suffix to src_name
+///
+/// In contrast to uncompressed_name(), we check only suffixes that are valid
+/// for the specified file format.
+static char *
+compressed_name(const char *src_name, size_t src_len)
+{
+ // The order of these must match the order in args.h.
+ static const char *const all_suffixes[][4] = {
+ {
+ ".xz",
+ ".txz",
+ NULL
+ }, {
+ ".lzma",
+#ifdef __DJGPP__
+ ".lzm",
+#endif
+ ".tlz",
+ NULL
+#ifdef HAVE_LZIP_DECODER
+ // This is needed to keep the table indexing in sync with
+ // enum format_type from coder.h.
+ }, {
+/*
+ ".lz",
+*/
+ NULL
+#endif
+ }, {
+ // --format=raw requires specifying the suffix
+ // manually or using stdout.
+ NULL
+ }
+ };
+
+ // args.c ensures these.
+ assert(opt_format != FORMAT_AUTO);
+#ifdef HAVE_LZIP_DECODER
+ assert(opt_format != FORMAT_LZIP);
+#endif
+
+ const size_t format = opt_format - 1;
+ const char *const *suffixes = all_suffixes[format];
+
+ // Look for known filename suffixes and refuse to compress them.
+ for (size_t i = 0; suffixes[i] != NULL; ++i) {
+ if (test_suffix(suffixes[i], src_name, src_len) != 0) {
+ msg_suffix(src_name, suffixes[i]);
+ return NULL;
+ }
+ }
+
+#ifdef __DJGPP__
+ // Recognize also the special suffix that is used when long
+ // filename (LFN) support isn't available. This suffix is
+ // recognized on LFN systems too.
+ if (opt_format == FORMAT_XZ && has_sfn_suffix(src_name, src_len)) {
+ msg_suffix(src_name, "-");
+ return NULL;
+ }
+#endif
+
+ if (custom_suffix != NULL) {
+ if (test_suffix(custom_suffix, src_name, src_len) != 0) {
+ msg_suffix(src_name, custom_suffix);
+ return NULL;
+ }
+ }
+
+ // TODO: Hmm, maybe it would be better to validate this in args.c,
+ // since the suffix handling when decoding is weird now.
+ if (opt_format == FORMAT_RAW && custom_suffix == NULL) {
+ message_error(_("%s: With --format=raw, "
+ "--suffix=.SUF is required unless "
+ "writing to stdout"), src_name);
+ return NULL;
+ }
+
+ const char *suffix = custom_suffix != NULL
+ ? custom_suffix : suffixes[0];
+ size_t suffix_len = strlen(suffix);
+
+#ifdef __DJGPP__
+ if (!_use_lfn(src_name)) {
+ // Long filename (LFN) support isn't available and we are
+ // limited to 8.3 short filenames (SFN).
+ //
+ // Look for suffix separator from the filename, and make sure
+ // that it is in the filename, not in a directory name.
+ const char *sufsep = strrchr(src_name, '.');
+ if (sufsep == NULL || sufsep[1] == '\0'
+ || has_dir_sep(sufsep)) {
+ // src_name has no filename extension.
+ //
+ // Examples:
+ // xz foo -> foo.xz
+ // xz -F lzma foo -> foo.lzm
+ // xz -S x foo -> foox
+ // xz -S x foo. -> foo.x
+ // xz -S x.y foo -> foox.y
+ // xz -S .x foo -> foo.x
+ // xz -S .x foo. -> foo.x
+ //
+ // Avoid double dots:
+ if (sufsep != NULL && sufsep[1] == '\0'
+ && suffix[0] == '.')
+ --src_len;
+
+ } else if (custom_suffix == NULL
+ && strcasecmp(sufsep, ".tar") == 0) {
+ // ".tar" is handled specially.
+ //
+ // Examples:
+ // xz foo.tar -> foo.txz
+ // xz -F lzma foo.tar -> foo.tlz
+ static const char *const tar_suffixes[] = {
+ ".txz", // .tar.xz
+ ".tlz", // .tar.lzma
+/*
+ ".tlz", // .tar.lz
+*/
+ };
+ suffix = tar_suffixes[format];
+ suffix_len = 4;
+ src_len -= 4;
+
+ } else {
+ if (custom_suffix == NULL && opt_format == FORMAT_XZ) {
+ // Instead of the .xz suffix, use a single
+ // character at the end of the filename
+ // extension. This is to minimize name
+ // conflicts when compressing multiple files
+ // with the same basename. E.g. foo.txt and
+ // foo.exe become foo.tx- and foo.ex-. Dash
+ // is rare as the last character of the
+ // filename extension, so it seems to be
+ // quite safe choice and it stands out better
+ // in directory listings than e.g. x. For
+ // comparison, gzip uses z.
+ suffix = "-";
+ suffix_len = 1;
+ }
+
+ if (suffix[0] == '.') {
+ // The first character of the suffix is a dot.
+ // Throw away the original filename extension
+ // and replace it with the new suffix.
+ //
+ // Examples:
+ // xz -F lzma foo.txt -> foo.lzm
+ // xz -S .x foo.txt -> foo.x
+ src_len = sufsep - src_name;
+
+ } else {
+ // The first character of the suffix is not
+ // a dot. Preserve the first 0-2 characters
+ // of the original filename extension.
+ //
+ // Examples:
+ // xz foo.txt -> foo.tx-
+ // xz -S x foo.c -> foo.cx
+ // xz -S ab foo.c -> foo.cab
+ // xz -S ab foo.txt -> foo.tab
+ // xz -S abc foo.txt -> foo.abc
+ //
+ // Truncate the suffix to three chars:
+ if (suffix_len > 3)
+ suffix_len = 3;
+
+ // If needed, overwrite 1-3 characters.
+ if (strlen(sufsep) > 4 - suffix_len)
+ src_len = sufsep - src_name
+ + 4 - suffix_len;
+ }
+ }
+ }
+#endif
+
+ char *dest_name = xmalloc(src_len + suffix_len + 1);
+
+ memcpy(dest_name, src_name, src_len);
+ memcpy(dest_name + src_len, suffix, suffix_len);
+ dest_name[src_len + suffix_len] = '\0';
+
+ return dest_name;
+}
+
+
+extern char *
+suffix_get_dest_name(const char *src_name)
+{
+ assert(src_name != NULL);
+
+ // Length of the name is needed in all cases to locate the end of
+ // the string to compare the suffix, so calculate the length here.
+ const size_t src_len = strlen(src_name);
+
+ return opt_mode == MODE_COMPRESS
+ ? compressed_name(src_name, src_len)
+ : uncompressed_name(src_name, src_len);
+}
+
+
+extern void
+suffix_set(const char *suffix)
+{
+ // Empty suffix and suffixes having a directory separator are
+ // rejected. Such suffixes would break things later.
+ if (suffix[0] == '\0' || has_dir_sep(suffix))
+ message_fatal(_("%s: Invalid filename suffix"), suffix);
+
+ // Replace the old custom_suffix (if any) with the new suffix.
+ free(custom_suffix);
+ custom_suffix = xstrdup(suffix);
+ return;
+}
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