busybox/findutils/grep.c

390 lines
10 KiB
C

/*
* Mini grep implementation for busybox using libc regex.
*
* Copyright (C) 1999,2000,2001 by Lineo, inc. and Mark Whitley
* Copyright (C) 1999,2000,2001 by Mark Whitley <markw@codepoet.org>
*
* 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 2 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, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
/*
* Apr 2004 by Vladimir Oleynik <dzo@simtreas.ru> -
* correction "-e pattern1 -e pattern2" logic and more optimizations.
*/
#include <stdio.h>
#include <stdlib.h>
#include <getopt.h>
#include <regex.h>
#include <string.h>
#include <errno.h>
#include "busybox.h"
/* options */
#define GREP_OPTS "lnqvscFiHhe:f:"
#define GREP_OPT_l 1
static char print_files_with_matches;
#define GREP_OPT_n 2
static char print_line_num;
#define GREP_OPT_q 4
static char be_quiet;
#define GREP_OPT_v 8
typedef char invert_search_t;
static invert_search_t invert_search;
#define GREP_OPT_s 16
static char suppress_err_msgs;
#define GREP_OPT_c 32
static char print_match_counts;
#define GREP_OPT_F 64
static char fgrep_flag;
#define GREP_OPT_i 128
#define GREP_OPT_H 256
#define GREP_OPT_h 512
#define GREP_OPT_e 1024
#define GREP_OPT_f 2048
#ifdef CONFIG_FEATURE_GREP_CONTEXT
#define GREP_OPT_CONTEXT "A:B:C"
#define GREP_OPT_A 4096
#define GREP_OPT_B 8192
#define GREP_OPT_C 16384
#define GREP_OPT_E 32768U
#else
#define GREP_OPT_CONTEXT ""
#define GREP_OPT_E 4096
#endif
#ifdef CONFIG_FEATURE_GREP_EGREP_ALIAS
# define OPT_EGREP "E"
#else
# define OPT_EGREP ""
#endif
static int reflags;
static int print_filename;
#ifdef CONFIG_FEATURE_GREP_CONTEXT
static int lines_before;
static int lines_after;
static char **before_buf;
static int last_line_printed;
#endif /* CONFIG_FEATURE_GREP_CONTEXT */
/* globals used internally */
static llist_t *pattern_head; /* growable list of patterns to match */
static char *cur_file; /* the current file we are reading */
static void print_line(const char *line, int linenum, char decoration)
{
#ifdef CONFIG_FEATURE_GREP_CONTEXT
/* possibly print the little '--' separator */
if ((lines_before || lines_after) && last_line_printed &&
last_line_printed < linenum - 1) {
puts("--");
}
last_line_printed = linenum;
#endif
if (print_filename)
printf("%s%c", cur_file, decoration);
if (print_line_num)
printf("%i%c", linenum, decoration);
puts(line);
}
extern void xregcomp(regex_t *preg, const char *regex, int cflags);
static int grep_file(FILE *file)
{
char *line;
invert_search_t ret;
int linenum = 0;
int nmatches = 0;
#ifdef CONFIG_FEATURE_GREP_CONTEXT
int print_n_lines_after = 0;
int curpos = 0; /* track where we are in the circular 'before' buffer */
int idx = 0; /* used for iteration through the circular buffer */
#endif /* CONFIG_FEATURE_GREP_CONTEXT */
while ((line = bb_get_chomped_line_from_file(file)) != NULL) {
llist_t *pattern_ptr = pattern_head;
linenum++;
ret = 0;
while (pattern_ptr) {
if (fgrep_flag) {
ret = strstr(line, pattern_ptr->data) != NULL;
} else {
/*
* test for a postitive-assertion match (regexec returns success (0)
* and the user did not specify invert search), or a negative-assertion
* match (regexec returns failure (REG_NOMATCH) and the user specified
* invert search)
*/
regex_t regex;
xregcomp(&regex, pattern_ptr->data, reflags);
ret |= regexec(&regex, line, 0, NULL, 0) == 0;
regfree(&regex);
}
pattern_ptr = pattern_ptr->link;
} /* while (pattern_ptr) */
if ((ret ^ invert_search)) {
if (print_files_with_matches || be_quiet)
free(line);
/* if we found a match but were told to be quiet, stop here */
if (be_quiet)
return -1;
/* keep track of matches */
nmatches++;
/* if we're just printing filenames, we stop after the first match */
if (print_files_with_matches)
break;
/* print the matched line */
if (print_match_counts == 0) {
#ifdef CONFIG_FEATURE_GREP_CONTEXT
int prevpos = (curpos == 0) ? lines_before - 1 : curpos - 1;
/* if we were told to print 'before' lines and there is at least
* one line in the circular buffer, print them */
if (lines_before && before_buf[prevpos] != NULL) {
int first_buf_entry_line_num = linenum - lines_before;
/* advance to the first entry in the circular buffer, and
* figure out the line number is of the first line in the
* buffer */
idx = curpos;
while (before_buf[idx] == NULL) {
idx = (idx + 1) % lines_before;
first_buf_entry_line_num++;
}
/* now print each line in the buffer, clearing them as we go */
while (before_buf[idx] != NULL) {
print_line(before_buf[idx], first_buf_entry_line_num, '-');
free(before_buf[idx]);
before_buf[idx] = NULL;
idx = (idx + 1) % lines_before;
first_buf_entry_line_num++;
}
}
/* make a note that we need to print 'after' lines */
print_n_lines_after = lines_after;
#endif /* CONFIG_FEATURE_GREP_CONTEXT */
print_line(line, linenum, ':');
}
}
#ifdef CONFIG_FEATURE_GREP_CONTEXT
else { /* no match */
/* Add the line to the circular 'before' buffer */
if(lines_before) {
free(before_buf[curpos]);
before_buf[curpos] = bb_xstrdup(line);
curpos = (curpos + 1) % lines_before;
}
}
/* if we need to print some context lines after the last match, do so */
if (print_n_lines_after && (last_line_printed != linenum)) {
print_line(line, linenum, '-');
print_n_lines_after--;
}
#endif /* CONFIG_FEATURE_GREP_CONTEXT */
free(line);
}
/* special-case file post-processing for options where we don't print line
* matches, just filenames and possibly match counts */
/* grep -c: print [filename:]count, even if count is zero */
if (print_match_counts) {
if (print_filename)
printf("%s:", cur_file);
printf("%d\n", nmatches);
}
/* grep -l: print just the filename, but only if we grepped the line in the file */
if (print_files_with_matches && nmatches > 0) {
puts(cur_file);
}
return nmatches;
}
static void load_regexes_from_file(llist_t *fopt)
{
char *line;
FILE *f;
while(fopt) {
llist_t *cur = fopt;
char *ffile = cur->data;
fopt = cur->link;
free(cur);
f = bb_xfopen(ffile, "r");
while ((line = bb_get_chomped_line_from_file(f)) != NULL) {
pattern_head = llist_add_to(pattern_head, line);
}
}
}
extern int grep_main(int argc, char **argv)
{
FILE *file;
int matched;
unsigned long opt;
llist_t *fopt;
/* do normal option parsing */
#ifdef CONFIG_FEATURE_GREP_CONTEXT
{
char *junk;
char *slines_after;
char *slines_before;
char *Copt;
bb_opt_complementaly = "H-h:e*:f*:C-AB";
opt = bb_getopt_ulflags(argc, argv,
GREP_OPTS GREP_OPT_CONTEXT OPT_EGREP,
&pattern_head, &fopt,
&slines_after, &slines_before, &Copt);
if(opt & GREP_OPT_C) {
/* C option unseted A and B options, but next -A or -B
may be ovewrite own option */
if(!(opt & GREP_OPT_A)) /* not overwtited */
slines_after = Copt;
if(!(opt & GREP_OPT_B)) /* not overwtited */
slines_before = Copt;
opt |= GREP_OPT_A|GREP_OPT_B; /* set for parse now */
}
if(opt & GREP_OPT_A) {
lines_after = strtoul(slines_after, &junk, 10);
if(*junk != '\0')
bb_error_msg_and_die("invalid context length argument");
}
if(opt & GREP_OPT_B) {
lines_before = strtoul(slines_before, &junk, 10);
if(*junk != '\0')
bb_error_msg_and_die("invalid context length argument");
}
/* sanity checks after parse may be invalid numbers ;-) */
if ((opt & (GREP_OPT_c|GREP_OPT_q|GREP_OPT_l))) {
opt &= ~GREP_OPT_n;
lines_before = 0;
lines_after = 0;
} else if(lines_before > 0)
before_buf = (char **)xcalloc(lines_before, sizeof(char *));
}
#else
/* with auto sanity checks */
bb_opt_complementaly = "H-h:e*:f*:c-n:q-n:l-n";
opt = bb_getopt_ulflags(argc, argv, GREP_OPTS OPT_EGREP,
&pattern_head, &fopt);
#endif
print_files_with_matches = opt & GREP_OPT_l;
print_line_num = opt & GREP_OPT_n;
be_quiet = opt & GREP_OPT_q;
invert_search = (opt & GREP_OPT_v) != 0; /* 0 | 1 */
suppress_err_msgs = opt & GREP_OPT_s;
print_match_counts = opt & GREP_OPT_c;
fgrep_flag = opt & GREP_OPT_F;
if(opt & GREP_OPT_H)
print_filename++;
if(opt & GREP_OPT_h)
print_filename--;
if(opt & GREP_OPT_f)
load_regexes_from_file(fopt);
#ifdef CONFIG_FEATURE_GREP_EGREP_ALIAS
if(bb_applet_name[0] == 'e' || (opt & GREP_OPT_E))
reflags = REG_EXTENDED | REG_NOSUB;
else
#endif
reflags = REG_NOSUB;
if(opt & GREP_OPT_i)
reflags |= REG_ICASE;
argv += optind;
argc -= optind;
/* if we didn't get a pattern from a -e and no command file was specified,
* argv[optind] should be the pattern. no pattern, no worky */
if (pattern_head == NULL) {
if (*argv == NULL)
bb_show_usage();
else {
pattern_head = llist_add_to(pattern_head, *argv++);
argc--;
}
}
/* argv[(optind)..(argc-1)] should be names of file to grep through. If
* there is more than one file to grep, we will print the filenames */
if (argc > 1) {
print_filename++;
/* If no files were specified, or '-' was specified, take input from
* stdin. Otherwise, we grep through all the files specified. */
} else if (argc == 0) {
argc++;
}
matched = 0;
while (argc--) {
cur_file = *argv++;
if(!cur_file || (*cur_file == '-' && !cur_file[1])) {
cur_file = "-";
file = stdin;
} else {
file = fopen(cur_file, "r");
}
if (file == NULL) {
if (!suppress_err_msgs)
bb_perror_msg("%s", cur_file);
} else {
matched += grep_file(file);
if(matched < 0) {
/* we found a match but were told to be quiet, stop here and
* return success */
break;
}
fclose(file);
}
}
#ifdef CONFIG_FEATURE_CLEAN_UP
/* destroy all the elments in the pattern list */
while (pattern_head) {
llist_t *pattern_head_ptr = pattern_head;
pattern_head = pattern_head->link;
free(pattern_head_ptr);
}
#endif
return !matched; /* invert return value 0 = success, 1 = failed */
}