Added support for ignoring '-g' per GNU ls, thanks to David Vrabel
[oweals/busybox.git] / grep.c
diff --git a/grep.c b/grep.c
index 3779e5510a9eda7ea7ae988f140bfc40b003e63c..a2e2ff813e20e596e004e4fcd2c682a640e541a5 100644 (file)
--- a/grep.c
+++ b/grep.c
 /*
- * Copyright (c) 1999 by David I. Bell
- * Permission is granted to use, distribute, or modify this source,
- * provided that this copyright notice remains intact.
+ * Mini grep implementation for busybox using libc regex.
  *
- * The "grep" command, taken from sash.
- * This provides basic file searching.
+ * Copyright (C) 1999,2000 by Lineo, inc.
+ * 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
+ * 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
  *
- * Permission to distribute this code under the GPL has been granted.
- * Modified for busybox by Erik Andersen <andersee@debian.org> <andersen@lineo.com>
  */
 
-#include "internal.h"
-#ifdef BB_GREP
-
 #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>
-
-
-const char grep_usage[] =
-"Search the input file(s) for lines matching the given pattern.\n"
-"\tI search stdin if no files are given.\n"
-"\tI can't grok full regular expressions.\n"
-"usage: grep [in] PATTERN [FILES]...\n"
-"\ti=ignore case, n=list line numbers\n";
+#include "internal.h"
 
+extern int optind; /* in unistd.h */
+extern int errno;  /* for use with strerror() */
+
+static const char grep_usage[] =
+       "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"
+       "\t-s\tsuppress file open/read error messages\n\n"
+#endif
+       ;
 
+/* 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;
 
-static BOOL    search
-       (const char * string, const char * word, BOOL ignoreCase);
+/* 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 */
 
 
-extern int 
-grep_main(struct FileInfo * unused, int argc, char ** argv)
+static void print_matched_line(char *line, int linenum)
 {
-       FILE *          fp;
-       const char *    word;
-       const char *    name;
-       const char *    cp;
-       BOOL            tellName;
-       BOOL            ignoreCase;
-       BOOL            tellLine;
-       long            line;
-       char            buf[BUF_SIZE];
-
-       ignoreCase = FALSE;
-       tellLine = FALSE;
-
-       argc--;
-       argv++;
-       if (argc < 1)
-       {
-               fprintf(stderr, "%s", grep_usage);
-               return 1;
-       }
-
-       if (**argv == '-')
-       {
-               argc--;
-               cp = *argv++;
-
-               while (*++cp) switch (*cp)
-               {
-                       case 'i':
-                               ignoreCase = TRUE;
-                               break;
+       if (print_filename)
+               printf("%s:", cur_file);
+       if (print_line_num)
+               printf("%i:", linenum);
 
-                       case 'n':
-                               tellLine = TRUE;
-                               break;
-
-                       default:
-                               fprintf(stderr, "Unknown option\n");
-                               return 1;
-               }
-       }
-
-       word = *argv++;
-       argc--;
-
-       tellName = (argc > 1);
-
-       while (argc-- > 0)
-       {
-               name = *argv++;
-
-               fp = fopen(name, "r");
-
-               if (fp == NULL)
-               {
-                       perror(name);
-
-                       continue;
-               }
-
-               line = 0;
-
-               while (fgets(buf, sizeof(buf), fp))
-               {
-                       line++;
-
-                       cp = &buf[strlen(buf) - 1];
+       printf("%s", line);
+}
 
-                       if (*cp != '\n')
-                               fprintf(stderr, "%s: Line too long\n", name);
+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 (search(buf, word, ignoreCase))
-                       {
-                               if (tellName)
-                                       printf("%s: ", name);
+                       nmatches++;
 
-                               if (tellLine)
-                                       printf("%ld: ", line);
+                       print_matched_line(line, linenum);
 
-                               fputs(buf, stdout);
-                       }
+               } else if (ret == REG_NOMATCH && invert_search) {
+                       print_matched_line(line, linenum);
                }
 
-               if (ferror(fp))
-                       perror(name);
-
-               fclose(fp);
+               free(line);
        }
-       return 0;
 }
 
-
-/*
- * See if the specified word is found in the specified string.
- */
-static BOOL
-search(const char * string, const char * word, BOOL ignoreCase)
+extern int grep_main(int argc, char **argv)
 {
-       const char *    cp1;
-       const char *    cp2;
-       int             len;
-       int             lowFirst;
-       int             ch1;
-       int             ch2;
-
-       len = strlen(word);
-
-       if (!ignoreCase)
-       {
-               while (TRUE)
-               {
-                       string = strchr(string, word[0]);
-
-                       if (string == NULL)
-                               return FALSE;
+       int opt;
+       int reflags;
+       int ret;
 
-                       if (memcmp(string, word, len) == 0)
-                               return TRUE;
+       /* do special-case option parsing */
+       if (argv[1] && (strcmp(argv[1], "--help") == 0))
+               usage(grep_usage);
 
-                       string++;
+       /* do normal option parsing */
+       while ((opt = getopt(argc, argv, "iHhnqvs")) > 0) {
+               switch (opt) {
+                       case 'i':
+                               ignore_case++;
+                               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;
                }
        }
 
-       /*
-        * Here if we need to check case independence.
-        * Do the search by lower casing both strings.
-        */
-       lowFirst = *word;
-
-       if (isupper(lowFirst))
-               lowFirst = tolower(lowFirst);
-
-       while (TRUE)
-       {
-               while (*string && (*string != lowFirst) &&
-                       (!isupper(*string) || (tolower(*string) != lowFirst)))
-               {
-                       string++;
+       /* 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);
+       }
 
-               if (*string == '\0')
-                       return FALSE;
-
-               cp1 = string;
-               cp2 = word;
-
-               do
-               {
-                       if (*cp2 == '\0')
-                               return TRUE;
-
-                       ch1 = *cp1++;
-
-                       if (isupper(ch1))
-                               ch1 = tolower(ch1);
-
-                       ch2 = *cp2++;
+       /* 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 no files were specified, or '-' was specified, take input from
+        * stdin. Otherwise, we grep through all the files specified. */
+       if (argv[optind+1] == NULL || (strcmp(argv[optind+1], "-") == 0)) {
+               grep_file(stdin);
+       } else {
+               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);
+                       }
+               }
+       }
 
-                       if (isupper(ch2))
-                               ch2 = tolower(ch2);
+       regfree(&regex);
 
-               }
-               while (ch1 == ch2);
+       if (nmatches == 0)
+               return 1;
 
-               string++;
-       }
+       return 0;
 }
-
-#endif
-/* END CODE */