freebsd-dev/contrib/less/pattern.c
Xin LI f6b74a7d16 MFV r317581: less v491.
MFC after:	1 month
2017-05-05 14:33:39 +00:00

385 lines
7.1 KiB
C

/*
* Copyright (C) 1984-2017 Mark Nudelman
*
* You may distribute under the terms of either the GNU General Public
* License or the Less License, as specified in the README file.
*
* For more information, see the README file.
*/
/*
* Routines to do pattern matching.
*/
#include "less.h"
extern int caseless;
/*
* Compile a search pattern, for future use by match_pattern.
*/
static int
compile_pattern2(pattern, search_type, comp_pattern, show_error)
char *pattern;
int search_type;
PATTERN_TYPE *comp_pattern;
int show_error;
{
if (search_type & SRCH_NO_REGEX)
return (0);
{
#if HAVE_GNU_REGEX
struct re_pattern_buffer *comp = (struct re_pattern_buffer *)
ecalloc(1, sizeof(struct re_pattern_buffer));
re_set_syntax(RE_SYNTAX_POSIX_EXTENDED);
if (re_compile_pattern(pattern, strlen(pattern), comp))
{
free(comp);
if (show_error)
error("Invalid pattern", NULL_PARG);
return (-1);
}
if (*comp_pattern != NULL)
{
regfree(*comp_pattern);
free(*comp_pattern);
}
*comp_pattern = comp;
#endif
#if HAVE_POSIX_REGCOMP
regex_t *comp = (regex_t *) ecalloc(1, sizeof(regex_t));
if (regcomp(comp, pattern, REGCOMP_FLAG))
{
free(comp);
if (show_error)
error("Invalid pattern", NULL_PARG);
return (-1);
}
if (*comp_pattern != NULL)
{
regfree(*comp_pattern);
free(*comp_pattern);
}
*comp_pattern = comp;
#endif
#if HAVE_PCRE
pcre *comp;
constant char *errstring;
int erroffset;
PARG parg;
comp = pcre_compile(pattern, 0,
&errstring, &erroffset, NULL);
if (comp == NULL)
{
parg.p_string = (char *) errstring;
if (show_error)
error("%s", &parg);
return (-1);
}
*comp_pattern = comp;
#endif
#if HAVE_RE_COMP
PARG parg;
if ((parg.p_string = re_comp(pattern)) != NULL)
{
if (show_error)
error("%s", &parg);
return (-1);
}
*comp_pattern = 1;
#endif
#if HAVE_REGCMP
char *comp;
if ((comp = regcmp(pattern, 0)) == NULL)
{
if (show_error)
error("Invalid pattern", NULL_PARG);
return (-1);
}
if (comp_pattern != NULL)
free(*comp_pattern);
*comp_pattern = comp;
#endif
#if HAVE_V8_REGCOMP
struct regexp *comp;
reg_show_error = show_error;
comp = regcomp(pattern);
reg_show_error = 1;
if (comp == NULL)
{
/*
* regcomp has already printed an error message
* via regerror().
*/
return (-1);
}
if (*comp_pattern != NULL)
free(*comp_pattern);
*comp_pattern = comp;
#endif
}
return (0);
}
/*
* Like compile_pattern2, but convert the pattern to lowercase if necessary.
*/
public int
compile_pattern(pattern, search_type, comp_pattern)
char *pattern;
int search_type;
PATTERN_TYPE *comp_pattern;
{
char *cvt_pattern;
int result;
if (caseless != OPT_ONPLUS)
cvt_pattern = pattern;
else
{
cvt_pattern = (char*) ecalloc(1, cvt_length(strlen(pattern), CVT_TO_LC));
cvt_text(cvt_pattern, pattern, (int *)NULL, (int *)NULL, CVT_TO_LC);
}
result = compile_pattern2(cvt_pattern, search_type, comp_pattern, 1);
if (cvt_pattern != pattern)
free(cvt_pattern);
return (result);
}
/*
* Forget that we have a compiled pattern.
*/
public void
uncompile_pattern(pattern)
PATTERN_TYPE *pattern;
{
#if HAVE_GNU_REGEX
if (*pattern != NULL)
{
regfree(*pattern);
free(*pattern);
}
*pattern = NULL;
#endif
#if HAVE_POSIX_REGCOMP
if (*pattern != NULL)
{
regfree(*pattern);
free(*pattern);
}
*pattern = NULL;
#endif
#if HAVE_PCRE
if (*pattern != NULL)
pcre_free(*pattern);
*pattern = NULL;
#endif
#if HAVE_RE_COMP
*pattern = 0;
#endif
#if HAVE_REGCMP
if (*pattern != NULL)
free(*pattern);
*pattern = NULL;
#endif
#if HAVE_V8_REGCOMP
if (*pattern != NULL)
free(*pattern);
*pattern = NULL;
#endif
}
/*
* Can a pattern be successfully compiled?
*/
public int
valid_pattern(pattern)
char *pattern;
{
PATTERN_TYPE comp_pattern;
int result;
CLEAR_PATTERN(comp_pattern);
result = compile_pattern2(pattern, 0, &comp_pattern, 0);
if (result != 0)
return (0);
uncompile_pattern(&comp_pattern);
return (1);
}
/*
* Is a compiled pattern null?
*/
public int
is_null_pattern(pattern)
PATTERN_TYPE pattern;
{
#if HAVE_GNU_REGEX
return (pattern == NULL);
#endif
#if HAVE_POSIX_REGCOMP
return (pattern == NULL);
#endif
#if HAVE_PCRE
return (pattern == NULL);
#endif
#if HAVE_RE_COMP
return (pattern == 0);
#endif
#if HAVE_REGCMP
return (pattern == NULL);
#endif
#if HAVE_V8_REGCOMP
return (pattern == NULL);
#endif
#if NO_REGEX
return (pattern == NULL);
#endif
}
/*
* Simple pattern matching function.
* It supports no metacharacters like *, etc.
*/
static int
match(pattern, pattern_len, buf, buf_len, pfound, pend)
char *pattern;
int pattern_len;
char *buf;
int buf_len;
char **pfound, **pend;
{
char *pp, *lp;
char *pattern_end = pattern + pattern_len;
char *buf_end = buf + buf_len;
for ( ; buf < buf_end; buf++)
{
for (pp = pattern, lp = buf; ; pp++, lp++)
{
char cp = *pp;
char cl = *lp;
if (caseless == OPT_ONPLUS && ASCII_IS_UPPER(cp))
cp = ASCII_TO_LOWER(cp);
if (cp != cl)
break;
if (pp == pattern_end || lp == buf_end)
break;
}
if (pp == pattern_end)
{
if (pfound != NULL)
*pfound = buf;
if (pend != NULL)
*pend = lp;
return (1);
}
}
return (0);
}
/*
* Perform a pattern match with the previously compiled pattern.
* Set sp and ep to the start and end of the matched string.
*/
public int
match_pattern(pattern, tpattern, line, line_len, sp, ep, notbol, search_type)
PATTERN_TYPE pattern;
char *tpattern;
char *line;
int line_len;
char **sp;
char **ep;
int notbol;
int search_type;
{
int matched;
*sp = *ep = NULL;
#if NO_REGEX
search_type |= SRCH_NO_REGEX;
#endif
if (search_type & SRCH_NO_REGEX)
matched = match(tpattern, strlen(tpattern), line, line_len, sp, ep);
else
{
#if HAVE_GNU_REGEX
{
struct re_registers search_regs;
pattern->not_bol = notbol;
pattern->regs_allocated = REGS_UNALLOCATED;
matched = re_search(pattern, line, line_len, 0, line_len, &search_regs) >= 0;
if (matched)
{
*sp = line + search_regs.start[0];
*ep = line + search_regs.end[0];
}
}
#endif
#if HAVE_POSIX_REGCOMP
{
regmatch_t rm;
int flags = (notbol) ? REG_NOTBOL : 0;
#ifdef REG_STARTEND
flags |= REG_STARTEND;
rm.rm_so = 0;
rm.rm_eo = line_len;
#endif
matched = !regexec(pattern, line, 1, &rm, flags);
if (matched)
{
#ifndef __WATCOMC__
*sp = line + rm.rm_so;
*ep = line + rm.rm_eo;
#else
*sp = rm.rm_sp;
*ep = rm.rm_ep;
#endif
}
}
#endif
#if HAVE_PCRE
{
int flags = (notbol) ? PCRE_NOTBOL : 0;
int ovector[3];
matched = pcre_exec(pattern, NULL, line, line_len,
0, flags, ovector, 3) >= 0;
if (matched)
{
*sp = line + ovector[0];
*ep = line + ovector[1];
}
}
#endif
#if HAVE_RE_COMP
matched = (re_exec(line) == 1);
/*
* re_exec doesn't seem to provide a way to get the matched string.
*/
*sp = *ep = NULL;
#endif
#if HAVE_REGCMP
*ep = regex(pattern, line);
matched = (*ep != NULL);
if (matched)
*sp = __loc1;
#endif
#if HAVE_V8_REGCOMP
#if HAVE_REGEXEC2
matched = regexec2(pattern, line, notbol);
#else
matched = regexec(pattern, line);
#endif
if (matched)
{
*sp = pattern->startp[0];
*ep = pattern->endp[0];
}
#endif
}
matched = (!(search_type & SRCH_NO_MATCH) && matched) ||
((search_type & SRCH_NO_MATCH) && !matched);
return (matched);
}