1 files changed, 229 insertions, 0 deletions
diff --git a/lib/search/hex.c b/lib/search/hex.c
new file mode 100644
index 0000000..40bae1e
--- /dev/null
+++ b/lib/search/hex.c
@@ -0,0 +1,229 @@
+/*
+   Search text engine.
+   HEX-style pattern matching
+
+   Copyright (C) 2009-2022
+   Free Software Foundation, Inc.
+
+   Written by:
+   Slava Zanko <slavazanko@gmail.com>, 2009.
+
+   This file is part of the Midnight Commander.
+
+   The Midnight Commander is free software: you can redistribute it
+   and/or modify it under the terms of the GNU General Public License as
+   published by the Free Software Foundation, either version 3 of the License,
+   or (at your option) any later version.
+
+   The Midnight Commander is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+
+#include "lib/global.h"
+#include "lib/strutil.h"
+#include "lib/search.h"
+#include "lib/strescape.h"
+
+#include "internal.h"
+
+/*** global variables ****************************************************************************/
+
+/*** file scope macro definitions ****************************************************************/
+
+typedef enum
+{
+    MC_SEARCH_HEX_E_OK,
+    MC_SEARCH_HEX_E_NUM_OUT_OF_RANGE,
+    MC_SEARCH_HEX_E_INVALID_CHARACTER,
+    MC_SEARCH_HEX_E_UNMATCHED_QUOTES
+} mc_search_hex_parse_error_t;
+
+/*** file scope type declarations ****************************************************************/
+
+/*** file scope variables ************************************************************************/
+
+/*** file scope functions ************************************************************************/
+
+static GString *
+mc_search__hex_translate_to_regex (const GString * astr, mc_search_hex_parse_error_t * error_ptr,
+                                   int *error_pos_ptr)
+{
+    GString *buff;
+    const char *str;
+    gsize str_len;
+    gsize loop = 0;
+    mc_search_hex_parse_error_t error = MC_SEARCH_HEX_E_OK;
+
+    buff = g_string_sized_new (64);
+    str = astr->str;
+    str_len = astr->len;
+
+    while (loop < str_len && error == MC_SEARCH_HEX_E_OK)
+    {
+        unsigned int val;
+        int ptr;
+
+        if (g_ascii_isspace (str[loop]))
+        {
+            /* Eat-up whitespace between tokens. */
+            while (g_ascii_isspace (str[loop]))
+                loop++;
+        }
+        /* cppcheck-suppress invalidscanf */
+        else if (sscanf (str + loop, "%x%n", &val, &ptr) == 1)
+        {
+            if (val > 255)
+                error = MC_SEARCH_HEX_E_NUM_OUT_OF_RANGE;
+            else
+            {
+                g_string_append_printf (buff, "\\x%02X", val);
+                loop += ptr;
+            }
+        }
+        else if (str[loop] == '"')
+        {
+            gsize loop2;
+
+            loop2 = loop + 1;
+
+            while (loop2 < str_len)
+            {
+                if (str[loop2] == '"')
+                    break;
+                if (str[loop2] == '\\' && loop2 + 1 < str_len)
+                    loop2++;
+                g_string_append_c (buff, str[loop2]);
+                loop2++;
+            }
+
+            if (str[loop2] == '\0')
+                error = MC_SEARCH_HEX_E_UNMATCHED_QUOTES;
+            else
+                loop = loop2 + 1;
+        }
+        else
+            error = MC_SEARCH_HEX_E_INVALID_CHARACTER;
+    }
+
+    if (error != MC_SEARCH_HEX_E_OK)
+    {
+        g_string_free (buff, TRUE);
+        if (error_ptr != NULL)
+            *error_ptr = error;
+        if (error_pos_ptr != NULL)
+            *error_pos_ptr = loop;
+        return NULL;
+    }
+
+    return buff;
+}
+
+/*** public functions ****************************************************************************/
+
+void
+mc_search__cond_struct_new_init_hex (const char *charset, mc_search_t * lc_mc_search,
+                                     mc_search_cond_t * mc_search_cond)
+{
+    GString *tmp;
+    mc_search_hex_parse_error_t error = MC_SEARCH_HEX_E_OK;
+    int error_pos = 0;
+
+    /*
+     * We may be searching in binary data, which is often invalid UTF-8.
+     *
+     * We have to create a non UTF-8 regex (that is, G_REGEX_RAW) or else, as
+     * the data is invalid UTF-8, both GLib's PCRE and our
+     * mc_search__g_regex_match_full_safe() are going to fail us. The former by
+     * not finding all bytes, the latter by overwriting the supposedly invalid
+     * UTF-8 with NULs.
+     *
+     * To do this, we specify "ASCII" as the charset.
+     *
+     * In fact, we can specify any charset other than "UTF-8": any such charset
+     * will trigger G_REGEX_RAW (see [1]). The output of [2] will be the same
+     * for all charsets because it skips the \xXX symbols
+     * mc_search__hex_translate_to_regex() outputs.
+     *
+     * But "ASCII" is the best choice because a hex pattern may contain a
+     * quoted string: this way we know [2] will ignore any characters outside
+     * ASCII letters range (these ignored chars will be copied verbatim to the
+     * output and will match as-is; in other words, in a case-sensitive manner;
+     * If the user is interested in case-insensitive searches of international
+     * text, he shouldn't be using hex search in the first place.)
+     *
+     * Switching out of UTF-8 has another advantage:
+     *
+     * When doing case-insensitive searches, GLib treats \xXX symbols as normal
+     * letters and therefore matches both "a" and "A" for the hex pattern
+     * "0x61". When we switch out of UTF-8, we're switching to using [2], which
+     * doesn't have this issue.
+     *
+     * [1] mc_search__cond_struct_new_init_regex
+     * [2] mc_search__cond_struct_new_regex_ci_str
+     */
+    if (str_isutf8 (charset))
+        charset = "ASCII";
+
+    tmp = mc_search__hex_translate_to_regex (mc_search_cond->str, &error, &error_pos);
+    if (tmp != NULL)
+    {
+        g_string_free (mc_search_cond->str, TRUE);
+        mc_search_cond->str = tmp;
+        mc_search__cond_struct_new_init_regex (charset, lc_mc_search, mc_search_cond);
+    }
+    else
+    {
+        const char *desc;
+
+        switch (error)
+        {
+        case MC_SEARCH_HEX_E_NUM_OUT_OF_RANGE:
+            desc =
+                _
+                ("Number out of range (should be in byte range, 0 <= n <= 0xFF, expressed in hex)");
+            break;
+        case MC_SEARCH_HEX_E_INVALID_CHARACTER:
+            desc = _("Invalid character");
+            break;
+        case MC_SEARCH_HEX_E_UNMATCHED_QUOTES:
+            desc = _("Unmatched quotes character");
+            break;
+        default:
+            desc = "";
+        }
+
+        lc_mc_search->error = MC_SEARCH_E_INPUT;
+        lc_mc_search->error_str =
+            g_strdup_printf (_("Hex pattern error at position %d:\n%s."), error_pos + 1, desc);
+    }
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+gboolean
+mc_search__run_hex (mc_search_t * lc_mc_search, const void *user_data,
+                    gsize start_search, gsize end_search, gsize * found_len)
+{
+    return mc_search__run_regex (lc_mc_search, user_data, start_search, end_search, found_len);
+}
+
+/* --------------------------------------------------------------------------------------------- */
+
+GString *
+mc_search_hex_prepare_replace_str (mc_search_t * lc_mc_search, GString * replace_str)
+{
+    (void) lc_mc_search;
+
+    return mc_g_string_dup (replace_str);
+}
+
+/* --------------------------------------------------------------------------------------------- */