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Diffstat (limited to 'lib/search/hex.c')
| -rw-r--r-- | lib/search/hex.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/lib/search/hex.c b/lib/search/hex.c new file mode 100644 index 0000000..50af6fb --- /dev/null +++ b/lib/search/hex.c @@ -0,0 +1,235 @@ +/* + Search text engine. + HEX-style pattern matching + + Copyright (C) 2009-2023 + 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 ****************************************************************/ + +/*** forward declarations (file scope functions) *************************************************/ + +/*** 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); +} + +/* --------------------------------------------------------------------------------------------- */ |