This is vodz' latest patch. Sorry it took so long...
[oweals/busybox.git] / grep.c
diff --git a/grep.c b/grep.c
index 52ef6c0fe7a0b5a58c5885127720b648fa2bfd53..03cc9f836dbed6cb80cd55d5979e9271f7708976 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) 1999,2000,2001 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
  *
- * 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 <getopt.h>
+#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";
-
-
-
-static int search (const char *string, const char *word, int ignoreCase);
-
-
-extern int grep_main (int argc, char **argv)
+#include "busybox.h"
+
+
+extern int optind; /* in unistd.h */
+extern int errno;  /* for use with strerror() */
+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)
 {
-    FILE *fp;
-    const char *word;
-    const char *name;
-    const char *cp;
-    int tellName;
-    int ignoreCase;
-    int 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;
-
-           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;
+#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);
+}
 
-       line = 0;
-
-       while (fgets (buf, sizeof (buf), fp)) {
-           line++;
 
-           cp = &buf[strlen (buf) - 1];
+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);
+       }
 
-           if (*cp != '\n')
-               fprintf (stderr, "%s: Line too long\n", name);
 
-           if (search (buf, word, ignoreCase)) {
-               if (tellName)
-                   printf ("%s: ", name);
+       /* special-case file post-processing for options where we don't print line
+        * matches, just filenames and possibly match counts */
 
-               if (tellLine)
-                   printf ("%ld: ", line);
+       /* 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);
+       }
 
-               fputs (buf, stdout);
-           }
+       /* 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);
        }
 
-       if (ferror (fp))
-           perror (name);
 
-       fclose (fp);
-    }
-    return 0;
+       /* remember if we matched */
+       if (nmatches != 0)
+               matched = 1;
 }
 
 
-/*
- * See if the specified word is found in the specified string.
- */
-static int search (const char *string, const char *word, int ignoreCase)
+static void add_regex(const char *restr)
 {
-    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;
+       regexes = xrealloc(regexes, sizeof(regex_t) * (++nregexes));
+       xregcomp(&regexes[nregexes-1], restr, reflags);
+}
 
-           if (memcmp (string, word, len) == 0)
-               return TRUE;
 
-           string++;
+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);
        }
-    }
+}
 
-    /* 
-     * Here if we need to check case independence.
-     * Do the search by lower casing both strings.
-     */
-    lowFirst = *word;
 
-    if (isupper (lowFirst))
-       lowFirst = tolower (lowFirst);
+#ifdef BB_FEATURE_CLEAN_UP
+static void destroy_regexes()
+{
+       if (regexes == NULL)
+               return;
 
-    while (TRUE) {
-       while (*string && (*string != lowFirst) &&
-              (!isupper (*string) || (tolower (*string) != lowFirst))) {
-           string++;
+       /* destroy all the elments in the array */
+       while (--nregexes >= 0) {
+               regfree(&regexes[nregexes]);
+               free(&regexes[nregexes]);
        }
+}
+#endif
 
-       if (*string == '\0')
-           return FALSE;
 
-       cp1 = string;
-       cp2 = word;
+extern int grep_main(int argc, char **argv)
+{
+       int opt;
+#ifdef BB_FEATURE_GREP_CONTEXT
+       char *junk;
+#endif
 
-       do {
-           if (*cp2 == '\0')
-               return TRUE;
+#ifdef BB_FEATURE_CLEAN_UP
+       /* destroy command strings on exit */
+       if (atexit(destroy_regexes) == -1)
+               perror_msg_and_die("atexit");
+#endif
 
-           ch1 = *cp1++;
+       /* 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 (isupper (ch1))
-               ch1 = tolower (ch1);
+       /* 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++;
+               }
+       }
 
-           ch2 = *cp2++;
+       /* 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
+       }
 
-           if (isupper (ch2))
-               ch2 = tolower (ch2);
+       /* 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);
+                       }
+               }
        }
-       while (ch1 == ch2);
 
-       string++;
-    }
-    return (TRUE);
+       return !matched; /* invert return value 0 = success, 1 = failed */
 }
-
-#endif
-/* END CODE */