diff options
Diffstat (limited to 'src/kwsearch.c')
| -rw-r--r-- | src/kwsearch.c | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/src/kwsearch.c b/src/kwsearch.c new file mode 100644 index 0000000..e9966d4 --- /dev/null +++ b/src/kwsearch.c @@ -0,0 +1,165 @@ +/* kwsearch.c - searching subroutines using kwset for grep. + Copyright 1992, 1998, 2000, 2007, 2009-2016 Free Software Foundation, Inc. + + 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, 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, write to the Free Software + Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA + 02110-1301, USA. */ + +/* Written August 1992 by Mike Haertel. */ + +#include <config.h> +#include "search.h" + +/* Whether -w considers WC to be a word constituent. */ +static bool +wordchar (wint_t wc) +{ + return wc == L'_' || iswalnum (wc); +} + +/* KWset compiled pattern. For Ecompile and Gcompile, we compile + a list of strings, at least one of which is known to occur in + any string matching the regexp. */ +static kwset_t kwset; + +void +Fcompile (char const *pattern, size_t size) +{ + size_t total = size; + + kwsinit (&kwset); + + char const *p = pattern; + do + { + size_t len; + char const *sep = memchr (p, '\n', total); + if (sep) + { + len = sep - p; + sep++; + total -= (len + 1); + } + else + { + len = total; + total = 0; + } + + char *buf = NULL; + if (match_lines) + { + buf = xmalloc (len + 2); + buf[0] = eolbyte; + memcpy (buf + 1, p, len); + buf[len + 1] = eolbyte; + p = buf; + len += 2; + } + kwsincr (kwset, p, len); + free (buf); + + p = sep; + } + while (p); + + kwsprep (kwset); +} + +size_t +Fexecute (char *buf, size_t size, size_t *match_size, + char const *start_ptr) +{ + char const *beg, *try, *end, *mb_start; + size_t len; + char eol = eolbyte; + struct kwsmatch kwsmatch; + size_t ret_val; + + for (mb_start = beg = start_ptr ? start_ptr : buf; beg <= buf + size; beg++) + { + size_t offset = kwsexec (kwset, beg - match_lines, + buf + size - beg + match_lines, &kwsmatch); + if (offset == (size_t) -1) + goto failure; + len = kwsmatch.size[0] - 2 * match_lines; + if (!match_lines && MB_CUR_MAX > 1 && !using_utf8 () + && mb_goback (&mb_start, beg + offset, buf + size) != 0) + { + /* We have matched a single byte that is not at the beginning of a + multibyte character. mb_goback has advanced MB_START past that + multibyte character. Now, we want to position BEG so that the + next kwsexec search starts there. Thus, to compensate for the + for-loop's BEG++, above, subtract one here. This code is + unusually hard to reach, and exceptionally, let's show how to + trigger it here: + + printf '\203AA\n'|LC_ALL=ja_JP.SHIFT_JIS src/grep -F A + + That assumes the named locale is installed. + Note that your system's shift-JIS locale may have a different + name, possibly including "sjis". */ + beg = mb_start - 1; + continue; + } + beg += offset; + if (start_ptr && !match_words) + goto success_in_beg_and_len; + if (match_lines) + { + len += start_ptr == NULL; + goto success_in_beg_and_len; + } + if (match_words) + for (try = beg; ; ) + { + char const *bol = memrchr (buf, eol, beg - buf); + bol = bol ? bol + 1 : buf; + if (wordchar (mb_prev_wc (bol, try, buf + size))) + break; + if (wordchar (mb_next_wc (try + len, buf + size))) + { + if (!len) + break; + offset = kwsexec (kwset, beg, --len, &kwsmatch); + if (offset == (size_t) -1) + break; + try = beg + offset; + len = kwsmatch.size[0]; + } + else if (!start_ptr) + goto success; + else + goto success_in_beg_and_len; + } /* for (try) */ + else + goto success; + } /* for (beg in buf) */ + + failure: + return -1; + + success: + end = memchr (beg + len, eol, (buf + size) - (beg + len)); + end = end ? end + 1 : buf + size; + beg = memrchr (buf, eol, beg - buf); + beg = beg ? beg + 1 : buf; + len = end - beg; + success_in_beg_and_len:; + size_t off = beg - buf; + + *match_size = len; + ret_val = off; + return ret_val; +} |