Brand, spankin', new grep that uses libc regex routines instead of the

hand-rolled ones. Sed still needs to be replaced and then the regexp stuff can
be axed.

1 files changed, 155 insertions, 100 deletions

diff --git a/grep.c b/grep.c
index 0e495ff87..aca469e2f 100644
--- a/grep.c
+++ b/grep.c
@@ -1,10 +1,8 @@
-/* vi: set sw=4 ts=4: */
 /*
- * Mini grep implementation for busybox
- *
+ * Mini grep implementation for busybox using libc regex.
  *
  * Copyright (C) 1999,2000 by Lineo, inc.
- * Written by Erik Andersen <andersen@lineo.com>, <andersee@debian.org>
+ * Written by Mark Whitley <markw@lineo.com>, <markw@enol.com>
  *
  * 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
@@ -22,149 +20,206 @@
  *
  */
 
-/*
-	18-Dec-1999	Konstantin Boldyshev <konst@voshod.com>
-
-	+ -q option (be quiet) 
-	+ exit code depending on grep result (TRUE or FALSE)
-	  (useful for scripts)
-*/
-
-#include "internal.h"
-#include "regexp.h"
 #include <stdio.h>
-#include <dirent.h>
+#include <stdlib.h>
+#include <unistd.h> /* for getopt() */
+#include <regex.h>
+#include <string.h> /* for strerror() */
 #include <errno.h>
-#include <fcntl.h>
-#include <signal.h>
-#include <time.h>
-#include <ctype.h>
-#define BB_DECLARE_EXTERN
-#define bb_need_too_few_args
-#include "messages.c"
+#include "internal.h"
+
+extern int optind; /* in unistd.h */
+extern int errno;  /* for use with strerror() */
 
 static const char grep_usage[] =
-	"grep [OPTIONS]... PATTERN [FILE]...\n"
+	"grep [-ihHnqvs] pattern [files...]\n"
 #ifndef BB_FEATURE_TRIVIAL_HELP
 	"\nSearch for PATTERN in each FILE or standard input.\n\n"
 	"OPTIONS:\n"
+	"\t-H\tprefix output lines with filename where match was found\n"
 	"\t-h\tsuppress the prefixing filename on output\n"
 	"\t-i\tignore case distinctions\n"
 	"\t-n\tprint line number with output lines\n"
 	"\t-q\tbe quiet. Returns 0 if result was found, 1 otherwise\n"
-	"\t-v\tselect non-matching lines\n\n"
-#if defined BB_REGEXP
-	"This version of grep matches full regular expressions.\n";
-#else
-	"This version of grep matches strings (not regular expressions).\n"
-#endif
+	"\t-v\tselect non-matching lines\n"
+	"\t-s\tsuppress file open/read error messages\n\n"
 #endif
 	;
 
-static int match = FALSE, beQuiet = FALSE;
+static const int GROWBY = 80; /* how large we will grow strings by */
+
+/* options */
+static int ignore_case       = 0;
+static int print_filename    = 0;
+static int print_line_num    = 0;
+static int be_quiet          = 0;
+static int invert_search     = 0;
+static int suppress_err_msgs = 0;
+
+/* globals */
+static regex_t regex; /* storage space for compiled regular expression */
+static int nmatches = 0; /* keeps track of the number of matches */
+static char *cur_file = NULL; /* the current file we are reading */
+
 
-static void do_grep(FILE * fp, char *needle, char *fileName, int tellName,
-					int ignoreCase, int tellLine, int invertSearch)
+/* This returns a malloc'ed char * which must be stored and free'ed */
+/* XXX: This function should probably go in a 'common'/'util'/'misc' file
+ * somewhere so it can be used by other folks. */
+static char *get_line_from_file(FILE *file)
 {
-	long line = 0;
-	char *haystack;
-	int  truth = !invertSearch;
+	int ch;
+	int idx = 0;
+	char *linebuf = NULL;
+	int linebufsz = 0;
+
+	while (1) {
+		ch = fgetc(file);
+		if (ch == EOF)
+			break;
+		/* grow the line buffer as necessary */
+		if (idx > linebufsz-1)
+			linebuf = realloc(linebuf, linebufsz += GROWBY);
+		linebuf[idx++] = (char)ch;
+		if ((char)ch == '\n')
+			break;
+	}
+
+	if (idx == 0)
+		return NULL;
+
+	linebuf[idx] = 0;
+	return linebuf;
+}
+
+static void print_matched_line(char *line, int linenum)
+{
+	if (print_filename)
+		printf("%s:", cur_file);
+	if (print_line_num)
+		printf("%i:", linenum);
+
+	printf("%s", line);
+}
 
-	while ((haystack = cstring_lineFromFile(fp))) {
-		line++;
-		if (find_match(haystack, needle, ignoreCase) == truth) {
-			if (tellName == TRUE)
-				printf("%s:", fileName);
+static void grep_file(FILE *file)
+{
+	char *line = NULL;
+	int ret;
+	int linenum = 0;
+
+	while ((line = get_line_from_file(file)) != NULL) {
+		linenum++;
+		ret = regexec(&regex, line, 0, NULL, 0);
+		if (ret == 0 && !invert_search) { /* match */
+
+			/* if we found a match but were told to be quiet, stop here and
+			 * return success */
+			if (be_quiet) {
+				regfree(&regex);
+				exit(0);
+			}
 
-			if (tellLine == TRUE)
-				printf("%ld:", line);
+			nmatches++;
 
-			if (beQuiet == FALSE)
-				fputs(haystack, stdout);
+			print_matched_line(line, linenum);
 
-			match = TRUE;
+		} else if (ret == REG_NOMATCH && invert_search) {
+			print_matched_line(line, linenum);
 		}
-		free(haystack);
+
+		free(line);
 	}
 }
 
-
 extern int grep_main(int argc, char **argv)
 {
-	FILE *fp;
-	char *needle;
-	char *fileName;
-	int tellName     = TRUE;
-	int ignoreCase   = FALSE;
-	int tellLine     = FALSE;
-	int invertSearch = FALSE;
-
-	if (argc < 1) {
+	int opt;
+	int reflags;
+	int ret;
+
+	/* do special-case option parsing */
+	if (argv[1] && (strcmp(argv[1], "--help") == 0))
 		usage(grep_usage);
-	}
-	argv++;
 
-	while (--argc >= 0 && *argv && (**argv == '-')) {
-		while (*++(*argv)) {
-			switch (**argv) {
+	/* do normal option parsing */
+	while ((opt = getopt(argc, argv, "iHhnqvs")) > 0) {
+		switch (opt) {
 			case 'i':
-				ignoreCase = TRUE;
+				ignore_case++;
+				break;
+			case 'H':
+				print_filename++;
 				break;
-
 			case 'h':
-				tellName = FALSE;
+				print_filename--;
 				break;
-
 			case 'n':
-				tellLine = TRUE;
+				print_line_num++;
 				break;
-
 			case 'q':
-				beQuiet = TRUE;
+				be_quiet++;
 				break;
-
 			case 'v':
-				invertSearch = TRUE;
+				invert_search++;
+				break;
+			case 's':
+				suppress_err_msgs++;
 				break;
-
-			default:
-				usage(grep_usage);
-			}
 		}
-		argv++;
 	}
 
-	if (argc == 0 || *argv == NULL) {
-		fatalError(too_few_args, "grep");
+	/* argv[optind] should be the regex pattern; no pattern, no worky */
+	if (argv[optind] == NULL)
+		usage(grep_usage);
+
+	/* compile the regular expression */
+	reflags = REG_NOSUB; /* we're not going to mess with sub-expressions */
+	if (ignore_case)
+		reflags |= REG_ICASE;
+	if ((ret = regcomp(&regex, argv[optind], reflags)) != 0) {
+		int errmsgsz = regerror(ret, &regex, NULL, 0);
+		char *errmsg = malloc(errmsgsz);
+		if (errmsg == NULL) {
+			fprintf(stderr, "grep: memory error\n");
+			regfree(&regex);
+			exit(1);
+		}
+		regerror(ret, &regex, errmsg, errmsgsz);
+		fprintf(stderr, "grep: %s\n", errmsg);
+		free(errmsg);
+		regfree(&regex);
+		exit(1);
 	}
 
-	needle = *argv++;
-	argc--;
+	/* argv[(optind+1)..(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+1) > 0)
+		print_filename++;
 
-	if (argc == 0) {
-		do_grep(stdin, needle, "stdin", FALSE, ignoreCase, tellLine, invertSearch);
+	/* If no files were specified, take input from stdin. Otherwise, we grep
+	 * through all the files specified. */
+	if (argv[optind+1] == NULL) {
+		grep_file(stdin);
 	} else {
-		/* Never print the filename for just one file */
-		if (argc == 1)
-			tellName = FALSE;
-		while (argc-- > 0) {
-			fileName = *argv++;
-
-			fp = fopen(fileName, "r");
-			if (fp == NULL) {
-				perror(fileName);
-				continue;
+		int i;
+		FILE *file;
+		for (i = optind + 1; i < argc; i++) {
+			cur_file = argv[i];
+			file = fopen(cur_file, "r");
+			if (file == NULL) {
+				if (!suppress_err_msgs)
+					fprintf(stderr, "grep: %s: %s\n", cur_file, strerror(errno));
+			} else {
+				grep_file(file);
+				fclose(file);
 			}
-
-			do_grep(fp, needle, fileName, tellName, ignoreCase, tellLine, invertSearch);
-
-			if (ferror(fp))
-				perror(fileName);
-			fclose(fp);
 		}
 	}
-	return(match);
-}
 
+	regfree(&regex);
 
-/* END CODE */
+	if (nmatches == 0)
+		return 1;
+
+	return 0;
+}