/* * Mini grep implementation for busybox using libc regex. * * Copyright (C) 1999,2000 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 * */#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_CONTEXTextern 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] = 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 /* 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_UPstatic void destroy_regexes(){	if (regexes == NULL)		return;	/* destroy all the elments in the array */	while (--nregexes >= 0) {		regfree(&(regexes[nregexes]));	}	if (regexes)	    free(regexes);}#endifextern int grep_main(int argc, char **argv){	int opt;#if defined BB_FEATURE_GREP_CONTEXT || defined BB_FEATURE_GREP_EGREP_ALIAS	char *junk;#endif#ifdef BB_FEATURE_CLEAN_UP	/* destroy command strings on exit */	atexit(destroy_regexes);#endif#ifdef BB_FEATURE_GREP_EGREP_ALIAS	junk = get_last_path_component(argv[0]);	if (junk && strcmp(junk, "egrep") == 0)		reflags |= REG_EXTENDED;#endif	/* do normal option parsing */	while ((opt = getopt(argc, argv, "iHhlnqvsce:f:"#ifdef BB_FEATURE_GREP_CONTEXT"A:B:C:"#endif#ifdef BB_FEATURE_GREP_EGREP_ALIAS"E"#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;#ifdef BB_FEATURE_GREP_EGREP_ALIAS			case 'E':				reflags |= REG_EXTENDED;				break;#endif			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 **)xcalloc(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 **)xcalloc(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 */}