lib/regex-quote.h

   1 /* Construct a regular expression from a literal string.
   2    Copyright (C) 1995, 2010-2024 Free Software Foundation, Inc.
   3    Written by Bruno Haible <haible@clisp.cons.org>, 2010.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation, either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _REGEX_QUOTE_H
  19 #define _REGEX_QUOTE_H
  20
  21 /* This file uses _GL_ATTRIBUTE_MALLOC, _GL_ATTRIBUTE_RETURNS_NONNULL.  */
  22 #if !_GL_CONFIG_H_INCLUDED
  23  #error "Please include config.h first."
  24 #endif
  25
  26 #include <stdlib.h>
  27
  28 /* Specifies a quotation task for converting a fixed string to a regular
  29    expression pattern.  */
  30 struct regex_quote_spec
  31 {
  32   /* True if the regular expression pattern consists of multibyte characters
  33      (in the encoding given by the LC_CTYPE category of the locale),
  34      false if it consists of single bytes or UTF-8 characters.  */
  35   unsigned int /*bool*/ multibyte : 1;
  36   /* True if the regular expression pattern shall match only entire lines.  */
  37   unsigned int /*bool*/ anchored : 1;
  38   /* Set of characters that need to be escaped (all ASCII), as a
  39      NUL-terminated string.  */
  40   char special[30 + 1];
  41 };
  42
  43
  44 /* Creates a quotation task that produces a POSIX regular expression, that is,
  45    a pattern that can be compiled with regcomp().
  46    CFLAGS can be 0 or REG_EXTENDED.
  47    If it is 0, the result is a Basic Regular Expression (BRE)
  48    <https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html#tag_09_03>.
  49    If it is REG_EXTENDED, the result is an Extended Regular Expression (ERE)
  50    <https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap09.html#tag_09_04>.
  51    If ANCHORED is false, the regular expression will match substrings of lines.
  52    If ANCHORED is true, it will match only complete lines,  */
  53 extern struct regex_quote_spec
  54        regex_quote_spec_posix (int cflags, bool anchored);
  55
  56 /* Creates a quotation task that produces a regular expression that can be
  57    compiled with the GNU API function re_compile_pattern().
  58    SYNTAX describes the syntax of the regular expression (such as
  59    RE_SYNTAX_POSIX_BASIC, RE_SYNTAX_POSIX_EXTENDED, RE_SYNTAX_EMACS, all
  60    defined in <regex.h>).  It must be the same value as 're_syntax_options'
  61    at the moment of the re_compile_pattern() call.
  62    If ANCHORED is false, the regular expression will match substrings of lines.
  63    If ANCHORED is true, it will match only complete lines,  */
  64 extern struct regex_quote_spec
  65        regex_quote_spec_gnu (unsigned long /*reg_syntax_t*/ syntax, bool anchored);
  66
  67 /* Creates a quotation task that produces a PCRE regular expression, that is,
  68    a pattern that can be compiled with pcre_compile().
  69    OPTIONS is the same value as the second argument passed to pcre_compile().
  70    If ANCHORED is false, the regular expression will match substrings of lines.
  71    If ANCHORED is true, it will match only complete lines,  */
  72 extern struct regex_quote_spec
  73        regex_quote_spec_pcre (int options, bool anchored);
  74
  75
  76 /* Returns the number of bytes needed for the quoted string.  */
  77 extern size_t
  78        regex_quote_length (const char *string, const struct regex_quote_spec *spec);
  79
  80 /* Copies the quoted string to p and returns the incremented p.
  81    There must be room for regex_quote_length (string, spec) + 1 bytes at p.  */
  82 extern char *
  83        regex_quote_copy (char *restrict p,
  84                          const char *string, const struct regex_quote_spec *spec);
  85
  86 /* Returns the freshly allocated quoted string.  */
  87 extern char *
  88        regex_quote (const char *string, const struct regex_quote_spec *spec)
  89        _GL_ATTRIBUTE_MALLOC _GL_ATTRIBUTE_DEALLOC_FREE
  90        _GL_ATTRIBUTE_RETURNS_NONNULL;
  91
  92
  93 #endif /* _REGEX_QUOTE_H */