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/findutils/grep.c b/findutils/grep.c
index 0e495ff87..aca469e2f 100644
--- a/findutils/grep.c
+++ b/findutils/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;
+}