root/lib/strutil/replace.c

/*   */

DEFINITIONS

1. str_replace_all

   1 /*
   2    Functions for replacing substrings in strings.
   3 
   4    Copyright (C) 2013-2024
   5    Free Software Foundation, Inc.
   6 
   7    Written by:
   8    Slava Zanko <slavazanko@gmail.com>, 2013;
   9 
  10    This file is part of the Midnight Commander.
  11 
  12    The Midnight Commander is free software: you can redistribute it
  13    and/or modify it under the terms of the GNU General Public License as
  14    published by the Free Software Foundation, either version 3 of the License,
  15    or (at your option) any later version.
  16 
  17    The Midnight Commander is distributed in the hope that it will be useful,
  18    but WITHOUT ANY WARRANTY; without even the implied warranty of
  19    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20    GNU General Public License for more details.
  21 
  22    You should have received a copy of the GNU General Public License
  23    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  24  */
  25 
  26 #include <config.h>
  27 
  28 #include "lib/global.h"
  29 #include "lib/strescape.h"
  30 #include "lib/strutil.h"
  31 
  32 /*** global variables ****************************************************************************/
  33 
  34 /*** file scope macro definitions ****************************************************************/
  35 
  36 /*** file scope type declarations ****************************************************************/
  37 
  38 /*** forward declarations (file scope functions) *************************************************/
  39 
  40 /*** file scope variables ************************************************************************/
  41 
  42 /* --------------------------------------------------------------------------------------------- */
  43 /*** file scope functions ************************************************************************/
  44 /* --------------------------------------------------------------------------------------------- */
  45 
  46 /* --------------------------------------------------------------------------------------------- */
  47 /*** public functions ****************************************************************************/
  48 /* --------------------------------------------------------------------------------------------- */
  49 /**
  50  * Replace all substrings 'needle' in string 'haystack' by 'replacement'.
  51  * If the 'needle' in the 'haystack' is escaped by backslash,
  52  * then this occurrence isn't be replaced.
  53  *
  54  * @param haystack    string contains substrings for replacement. Cannot be NULL.
  55  * @param needle      string for search. Cannot be NULL.
  56  * @param replacement string for replace. Cannot be NULL.
  57  * @return newly allocated string with replaced substrings or NULL if @haystack is empty.
  58  */
  59 
  60 char *
  61 str_replace_all (const char *haystack, const char *needle, const char *replacement)
     /*   */
  62 {
  63     size_t needle_len, replacement_len;
  64     GString *return_str = NULL;
  65     char *needle_in_str;
  66 
  67     needle_len = strlen (needle);
  68     replacement_len = strlen (replacement);
  69 
  70     while ((needle_in_str = strstr (haystack, needle)) != NULL)
  71     {
  72         if (return_str == NULL)
  73             return_str = g_string_sized_new (32);
  74 
  75         if (strutils_is_char_escaped (haystack, needle_in_str))
  76         {
  77             char *backslash = needle_in_str - 1;
  78 
  79             if (haystack != backslash)
  80                 g_string_append_len (return_str, haystack, backslash - haystack);
  81             g_string_append_len (return_str, needle_in_str, needle_in_str - backslash);
  82             haystack = needle_in_str + 1;
  83         }
  84         else
  85         {
  86             if (needle_in_str != haystack)
  87                 g_string_append_len (return_str, haystack, needle_in_str - haystack);
  88             g_string_append_len (return_str, replacement, replacement_len);
  89             haystack = needle_in_str + needle_len;
  90         }
  91     }
  92 
  93     if (*haystack != '\0')
  94     {
  95         if (return_str == NULL)
  96             return strdup (haystack);
  97 
  98         g_string_append (return_str, haystack);
  99     }
 100 
 101     return (return_str != NULL ? g_string_free (return_str, FALSE) : NULL);
 102 }
 103 
 104 /* --------------------------------------------------------------------------------------------- */

/*   */