grep.c - codeaurora/busybox - Gitiles

 /*
  * Mini grep implementation for busybox using libc regex.
  *
  * Copyright (C) 1999,2000,2001 by Lineo, inc.
  * Written by Mark Whitley <markw@lineo.com>, <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
  *
  */

 #include <stdio.h>
 #include <stdlib.h>
 #include <getopt.h>
 #include <regex.h>
 #include <string.h> /* for strerror() */
 #include <errno.h>
 #include "busybox.h"


 extern int optind; /* in unistd.h */
 extern void xregcomp(regex_t *preg, const char *regex, int cflags); /* in busybox.h */

 /* options */
 static int reflags            = REG_NOSUB;
 static int print_filename     = 0;
 static int print_line_num     = 0;
 static int print_match_counts = 0;
 static int be_quiet           = 0;
 static int invert_search      = 0;
 static int suppress_err_msgs  = 0;
 static int print_files_with_matches  = 0;

 #ifdef BB_FEATURE_GREP_CONTEXT
 extern char *optarg; /* in getopt.h */
 static int lines_before      = 0;
 static int lines_after       = 0;
 static char **before_buf     = NULL;
 static int last_line_printed = 0;
 #endif /* BB_FEATURE_GREP_CONTEXT */

 /* globals used internally */
 static regex_t *regexes = NULL; /* growable array of compiled regular expressions */
 static int nregexes = 0; /* number of elements in above arrary */
 static int matched; /* keeps track of whether we ever matched */
 static char *cur_file = NULL; /* the current file we are reading */


 static void print_line(const char *line, int linenum, char decoration)
 {
 #ifdef BB_FEATURE_GREP_CONTEXT
 	/* possibly print the little '--' seperator */
 	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);
 }


 static void grep_file(FILE *file)
 {
 	char *line = NULL;
 	int ret;
 	int linenum = 0;
 	int nmatches = 0;
 	int i;
 #ifdef BB_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 /* BB_FEATURE_GREP_CONTEXT */

 	while ((line = get_line_from_file(file)) != NULL) {
 		chomp(line);
 		linenum++;

 		for (i = 0; i < nregexes; i++) {
 			/*
 			 * 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)
 			 */
 			ret = regexec(&regexes[i], line, 0, NULL, 0);
 			if ((ret == 0 && !invert_search) || (ret == REG_NOMATCH && invert_search)) {

 				/* if we found a match but were told to be quiet, stop here and
 				 * return success */
 				if (be_quiet)
 					exit(0);

 				/* 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 BB_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 /* BB_FEATURE_GREP_CONTEXT */
 					print_line(line, linenum, ':');
 				}
 			}
 #ifdef BB_FEATURE_GREP_CONTEXT
 			else { /* no match */
 				/* Add the line to the circular 'before' buffer */
 				if(lines_before) {
 					if(before_buf[curpos])
 						free(before_buf[curpos]);
 					before_buf[curpos] = strdup(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 /* BB_FEATURE_GREP_CONTEXT */
 		} /* for */
 		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);
 		if (print_files_with_matches && nmatches > 0)
 			printf("1\n");
 		else
 		    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);
 	}


 	/* remember if we matched */
 	if (nmatches != 0)
 		matched = 1;
 }


 static void add_regex(const char *restr)
 {
 	regexes = xrealloc(regexes, sizeof(regex_t) * (++nregexes));
 	xregcomp(&regexes[nregexes-1], restr, reflags);
 }


 static void	load_regexes_from_file(const char *filename)
 {
 	char *line;
 	FILE *f = xfopen(filename, "r");
 	while ((line = get_line_from_file(f)) != NULL) {
 		chomp(line);
 		add_regex(line);
 		free(line);
 	}
 }


 #ifdef BB_FEATURE_CLEAN_UP
 static void destroy_regexes()
 {
 	if (regexes == NULL)
 		return;

 	/* destroy all the elments in the array */
 	while (--nregexes >= 0) {
 		regfree(&regexes[nregexes]);
 		free(&regexes[nregexes]);
 	}
 }
 #endif


 extern int grep_main(int argc, char **argv)
 {
 	int opt;
 #ifdef BB_FEATURE_GREP_CONTEXT
 	char *junk;
 #endif

 #ifdef BB_FEATURE_CLEAN_UP
 	/* destroy command strings on exit */
 	if (atexit(destroy_regexes) == -1)
 		perror_msg_and_die("atexit");
 #endif

 	/* do normal option parsing */
 	while ((opt = getopt(argc, argv, "iHhlnqvsce:f:"
 #ifdef BB_FEATURE_GREP_CONTEXT
 "A:B:C:"
 #endif
 )) > 0) {
 		switch (opt) {
 			case 'i':
 				reflags |= REG_ICASE;
 				break;
 			case 'l':
 				print_files_with_matches++;
 				break;
 			case 'H':
 				print_filename++;
 				break;
 			case 'h':
 				print_filename--;
 				break;
 			case 'n':
 				print_line_num++;
 				break;
 			case 'q':
 				be_quiet++;
 				break;
 			case 'v':
 				invert_search++;
 				break;
 			case 's':
 				suppress_err_msgs++;
 				break;
 			case 'c':
 				print_match_counts++;
 				break;
 			case 'e':
 				add_regex(optarg);
 				break;
 			case 'f':
 				load_regexes_from_file(optarg);
 				break;
 #ifdef BB_FEATURE_GREP_CONTEXT
 			case 'A':
 				lines_after = strtoul(optarg, &junk, 10);
 				if(*junk != '\0')
 					error_msg_and_die("invalid context length argument");
 				break;
 			case 'B':
 				lines_before = strtoul(optarg, &junk, 10);
 				if(*junk != '\0')
 					error_msg_and_die("invalid context length argument");
 				before_buf = (char **)calloc(lines_before, sizeof(char *));
 				break;
 			case 'C':
 				lines_after = lines_before = strtoul(optarg, &junk, 10);
 				if(*junk != '\0')
 					error_msg_and_die("invalid context length argument");
 				before_buf = (char **)calloc(lines_before, sizeof(char *));
 				break;
 #endif /* BB_FEATURE_GREP_CONTEXT */
 			default:
 				show_usage();
 		}
 	}

 	/* 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 (nregexes == 0) {
 		if (argv[optind] == NULL)
 			show_usage();
 		else {
 			add_regex(argv[optind]);
 			optind++;
 		}
 	}

 	/* sanity checks */
 	if (print_match_counts || be_quiet || print_files_with_matches) {
 		print_line_num = 0;
 #ifdef BB_FEATURE_GREP_CONTEXT
 		lines_before = 0;
 		lines_after = 0;
 #endif
 	}

 	/* 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) - (optind) > 0)
 		print_filename++;

 	/* If no files were specified, or '-' was specified, take input from
 	 * stdin. Otherwise, we grep through all the files specified. */
 	if (argv[optind] == NULL || (strcmp(argv[optind], "-") == 0)) {
 		grep_file(stdin);
 	}
 	else {
 		int i;
 		FILE *file;
 		for (i = optind; i < argc; i++) {
 			cur_file = argv[i];
 			file = fopen(cur_file, "r");
 			if (file == NULL) {
 				if (!suppress_err_msgs)
 					perror_msg("%s", cur_file);
 			}
 			else {
 				grep_file(file);
 				fclose(file);
 			}
 		}
 	}

 	return !matched; /* invert return value 0 = success, 1 = failed */
 }
	/*
	* Mini grep implementation for busybox using libc regex.
	*
	* Copyright (C) 1999,2000,2001 by Lineo, inc.
	* Written by Mark Whitley <markw@lineo.com>, <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
	*
	*/

	#include <stdio.h>
	#include <stdlib.h>
	#include <getopt.h>
	#include <regex.h>
	#include <string.h> /* for strerror() */
	#include <errno.h>
	#include "busybox.h"


	extern int optind; /* in unistd.h */
	extern void xregcomp(regex_t preg, const char regex, int cflags); /* in busybox.h */

	/* options */
	static int reflags = REG_NOSUB;
	static int print_filename = 0;
	static int print_line_num = 0;
	static int print_match_counts = 0;
	static int be_quiet = 0;
	static int invert_search = 0;
	static int suppress_err_msgs = 0;
	static int print_files_with_matches = 0;

	#ifdef BB_FEATURE_GREP_CONTEXT
	extern char optarg; / in getopt.h */
	static int lines_before = 0;
	static int lines_after = 0;
	static char **before_buf = NULL;
	static int last_line_printed = 0;
	#endif /* BB_FEATURE_GREP_CONTEXT */

	/* globals used internally */
	static regex_t regexes = NULL; / growable array of compiled regular expressions */
	static int nregexes = 0; /* number of elements in above arrary */
	static int matched; /* keeps track of whether we ever matched */
	static char cur_file = NULL; / the current file we are reading */


	static void print_line(const char *line, int linenum, char decoration)
	{
	#ifdef BB_FEATURE_GREP_CONTEXT
	/* possibly print the little '--' seperator */
	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);
	}


	static void grep_file(FILE *file)
	{
	char *line = NULL;
	int ret;
	int linenum = 0;
	int nmatches = 0;
	int i;
	#ifdef BB_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 /* BB_FEATURE_GREP_CONTEXT */

	while ((line = get_line_from_file(file)) != NULL) {
	chomp(line);
	linenum++;

	for (i = 0; i < nregexes; i++) {
	/*
	* 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)
	*/
	ret = regexec(&regexes[i], line, 0, NULL, 0);
	if ((ret == 0 && !invert_search) \|\| (ret == REG_NOMATCH && invert_search)) {

	/* if we found a match but were told to be quiet, stop here and
	* return success */
	if (be_quiet)
	exit(0);

	/* 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 BB_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 /* BB_FEATURE_GREP_CONTEXT */
	print_line(line, linenum, ':');
	}
	}
	#ifdef BB_FEATURE_GREP_CONTEXT
	else { /* no match */
	/* Add the line to the circular 'before' buffer */
	if(lines_before) {
	if(before_buf[curpos])
	free(before_buf[curpos]);
	before_buf[curpos] = strdup(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 /* BB_FEATURE_GREP_CONTEXT */
	} /* for */
	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);
	if (print_files_with_matches && nmatches > 0)
	printf("1\n");
	else
	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);
	}


	/* remember if we matched */
	if (nmatches != 0)
	matched = 1;
	}


	static void add_regex(const char *restr)
	{
	regexes = xrealloc(regexes, sizeof(regex_t) * (++nregexes));
	xregcomp(&regexes[nregexes-1], restr, reflags);
	}


	static void load_regexes_from_file(const char *filename)
	{
	char *line;
	FILE *f = xfopen(filename, "r");
	while ((line = get_line_from_file(f)) != NULL) {
	chomp(line);
	add_regex(line);
	free(line);
	}
	}


	#ifdef BB_FEATURE_CLEAN_UP
	static void destroy_regexes()
	{
	if (regexes == NULL)
	return;

	/* destroy all the elments in the array */
	while (--nregexes >= 0) {
	regfree(&regexes[nregexes]);
	free(&regexes[nregexes]);
	}
	}
	#endif


	extern int grep_main(int argc, char **argv)
	{
	int opt;
	#ifdef BB_FEATURE_GREP_CONTEXT
	char *junk;
	#endif

	#ifdef BB_FEATURE_CLEAN_UP
	/* destroy command strings on exit */
	if (atexit(destroy_regexes) == -1)
	perror_msg_and_die("atexit");
	#endif

	/* do normal option parsing */
	while ((opt = getopt(argc, argv, "iHhlnqvsce:f:"
	#ifdef BB_FEATURE_GREP_CONTEXT
	"A:B:C:"
	#endif
	)) > 0) {
	switch (opt) {
	case 'i':
	reflags \|= REG_ICASE;
	break;
	case 'l':
	print_files_with_matches++;
	break;
	case 'H':
	print_filename++;
	break;
	case 'h':
	print_filename--;
	break;
	case 'n':
	print_line_num++;
	break;
	case 'q':
	be_quiet++;
	break;
	case 'v':
	invert_search++;
	break;
	case 's':
	suppress_err_msgs++;
	break;
	case 'c':
	print_match_counts++;
	break;
	case 'e':
	add_regex(optarg);
	break;
	case 'f':
	load_regexes_from_file(optarg);
	break;
	#ifdef BB_FEATURE_GREP_CONTEXT
	case 'A':
	lines_after = strtoul(optarg, &junk, 10);
	if(*junk != '\0')
	error_msg_and_die("invalid context length argument");
	break;
	case 'B':
	lines_before = strtoul(optarg, &junk, 10);
	if(*junk != '\0')
	error_msg_and_die("invalid context length argument");
	before_buf = (char *)calloc(lines_before, sizeof(char ));
	break;
	case 'C':
	lines_after = lines_before = strtoul(optarg, &junk, 10);
	if(*junk != '\0')
	error_msg_and_die("invalid context length argument");
	before_buf = (char *)calloc(lines_before, sizeof(char ));
	break;
	#endif /* BB_FEATURE_GREP_CONTEXT */
	default:
	show_usage();
	}
	}

	/* 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 (nregexes == 0) {
	if (argv[optind] == NULL)
	show_usage();
	else {
	add_regex(argv[optind]);
	optind++;
	}
	}

	/* sanity checks */
	if (print_match_counts \|\| be_quiet \|\| print_files_with_matches) {
	print_line_num = 0;
	#ifdef BB_FEATURE_GREP_CONTEXT
	lines_before = 0;
	lines_after = 0;
	#endif
	}

	/* 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) - (optind) > 0)
	print_filename++;

	/* If no files were specified, or '-' was specified, take input from
	* stdin. Otherwise, we grep through all the files specified. */
	if (argv[optind] == NULL \|\| (strcmp(argv[optind], "-") == 0)) {
	grep_file(stdin);
	}
	else {
	int i;
	FILE *file;
	for (i = optind; i < argc; i++) {
	cur_file = argv[i];
	file = fopen(cur_file, "r");
	if (file == NULL) {
	if (!suppress_err_msgs)
	perror_msg("%s", cur_file);
	}
	else {
	grep_file(file);
	fclose(file);
	}
	}
	}

	return !matched; /* invert return value 0 = success, 1 = failed */
	}