From 2ae92044423ffb31e5fa85a4f5cad4116c44b26c Mon Sep 17 00:00:00 2001 From: Bruno Haible Date: Sat, 25 Sep 2010 12:38:20 +0200 Subject: [PATCH] New module 'regex-quote'. * lib/regex-quote.h: New file. * lib/regex-quote.c: New file. * modules/regex-quote: New file. Suggested by Reuben Thomas . --- ChangeLog | 8 +++++ lib/regex-quote.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++++ lib/regex-quote.h | 41 +++++++++++++++++++++++++ modules/regex-quote | 24 +++++++++++++++ 4 files changed, 159 insertions(+) create mode 100644 lib/regex-quote.c create mode 100644 lib/regex-quote.h create mode 100644 modules/regex-quote diff --git a/ChangeLog b/ChangeLog index d81db2e94..8b728d0bf 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,11 @@ +2010-09-25 Bruno Haible + + New module 'regex-quote'. + * lib/regex-quote.h: New file. + * lib/regex-quote.c: New file. + * modules/regex-quote: New file. + Suggested by Reuben Thomas . + 2010-09-24 Bruno Haible unistr/u8-strchr: Fix a test failure on i586 glibc systems. diff --git a/lib/regex-quote.c b/lib/regex-quote.c new file mode 100644 index 000000000..d962e50ee --- /dev/null +++ b/lib/regex-quote.c @@ -0,0 +1,86 @@ +/* Construct a regular expression from a literal string. + Copyright (C) 1995, 2010 Free Software Foundation, Inc. + Written by Bruno Haible , 2010. + + This program 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. + + This program 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 . */ + +#include + +/* Specification. */ +#include "regex-quote.h" + +#include + +#include "mbuiter.h" +#include "xalloc.h" + +/* Characters that are special in a BRE. */ +static const char bre_special[] = "$^.*[]\\"; + +/* Characters that are special in an ERE. */ +static const char ere_special[] = "$^.*[]\\+?()"; + +size_t +regex_quote_length (const char *string, int cflags) +{ + const char *special = (cflags != 0 ? ere_special : bre_special); + size_t length; + mbui_iterator_t iter; + + length = 0; + for (mbui_init (iter, string); mbui_avail (iter); mbui_advance (iter)) + { + /* We know that special contains only ASCII characters. */ + if (mb_len (mbui_cur (iter)) == 1 + && strchr (special, * mbui_cur_ptr (iter))) + length += 1; + length += mb_len (mbui_cur (iter)); + } + return length; +} + +/* Copies the quoted string to p and returns the incremented p. + There must be room for regex_quote_length (string, cflags) + 1 bytes at p. + */ +char * +regex_quote_copy (char *p, const char *string, int cflags) +{ + const char *special = (cflags != 0 ? ere_special : bre_special); + mbui_iterator_t iter; + + for (mbui_init (iter, string); mbui_avail (iter); mbui_advance (iter)) + { + /* We know that special contains only ASCII characters. */ + if (mb_len (mbui_cur (iter)) == 1 + && strchr (special, * mbui_cur_ptr (iter))) + *p++ = '\\'; + memcpy (p, mbui_cur_ptr (iter), mb_len (mbui_cur (iter))); + p += mb_len (mbui_cur (iter)); + } + return p; +} + +/* Returns the freshly allocated quoted string. */ +char * +regex_quote (const char *string, int cflags) +{ + size_t length = regex_quote_length (string, cflags); + char *result = XNMALLOC (length + 1, char); + char *p; + + p = result; + p = regex_quote_copy (p, string, cflags); + *p = '\0'; + return result; +} diff --git a/lib/regex-quote.h b/lib/regex-quote.h new file mode 100644 index 000000000..203750acd --- /dev/null +++ b/lib/regex-quote.h @@ -0,0 +1,41 @@ +/* Construct a regular expression from a literal string. + Copyright (C) 1995, 2010 Free Software Foundation, Inc. + Written by Bruno Haible , 2010. + + This program 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. + + This program 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 . */ + +#include + +/* regex_quote converts a literal string to a regular expression that will + look for this literal string. + cflags can be 0 or REG_EXTENDED. + If it is 0, the result is a Basic Regular Expression (BRE) + . + If it is REG_EXTENDED, the result is an Extended Regular Expression (ERE) + . + The result is not anchored; if you want it to match only complete lines, + you need to add "^" at the beginning of the result and "$" at the end of the + result. + */ + +/* Returns the number of bytes needed for the quoted string. */ +extern size_t regex_quote_length (const char *string, int cflags); + +/* Copies the quoted string to p and returns the incremented p. + There must be room for regex_quote_length (string, cflags) + 1 bytes at p. + */ +extern char * regex_quote_copy (char *p, const char *string, int cflags); + +/* Returns the freshly allocated quoted string. */ +extern char * regex_quote (const char *string, int cflags); diff --git a/modules/regex-quote b/modules/regex-quote new file mode 100644 index 000000000..2ca57b004 --- /dev/null +++ b/modules/regex-quote @@ -0,0 +1,24 @@ +Description: +Construct a regular expression from a literal string. + +Files: +lib/regex-quote.h +lib/regex-quote.c + +Depends-on: +xalloc +mbuiter + +configure.ac: + +Makefile.am: +lib_SOURCES += regex-quote.c + +Include: +"regex-quote.h" + +License: +GPL + +Maintainer: +Bruno Haible -- 2.11.0