diff options
Diffstat (limited to 'grep.c')
| -rw-r--r-- | grep.c | 201 |
1 files changed, 201 insertions, 0 deletions
@@ -0,0 +1,201 @@ +/* + * UNG's Not GNU + * + * Copyright (c) 2011, Jakob Kaivo <jakob@kaivo.net> + * + * Permission to use, copy, modify, and/or distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + * + */ + +#include <limits.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <unistd.h> +#include <regex.h> + +// GNU libc unsets ARG_MAX +#ifndef ARG_MAX +# define ARG_MAX _POSIX_ARG_MAX +#endif + + +const char *grep_desc = "search a file for a pattern"; +const char *grep_inv = "grep [-E|-F] [-c|-l|-q] [-insvx] -e pattern_list [-e pattern_list]... [-f pattern_file]... [file...]\ngrep [-E|-F] [-c|-l|-q] [-insvx] [-e pattern_list]... -f pattern_file [-f pattern_file]... [file...]\ngrep [-E|-F] [-c|-l|-q] [-insvx] pattern_list [file...]"; + +#define BASIC 0 +#define EXTENDED 1 +#define FIXED 2 + +#define NORMAL 0 +#define COUNT 1 +#define LIST 2 +#define QUIET 3 + +#define IGNORECASE 1 << 0 +#define LINENUMBERS 1 << 1 +#define SUPPRESS 1 << 2 +#define INVERT 1 << 3 +#define WHOLELINE 1 << 4 +#define FILENAMES 1 << 5 + +static int grep (int patterns, char **p, int type, int display, int flags, char *path) +{ + FILE *f = stdin; + char *buf = NULL; + int line = 0; + size_t nmatch; + size_t len = 0; + size_t nread; + regmatch_t pmatch[1]; + regex_t re; + int i; + int count = 0; + struct stat st; + + stat (path, &st); + if (S_ISDIR(st.st_mode)) + return 0; + + if (strcmp ("-", path)) + f = fopen (path, "r"); + + if (f == NULL) { + if (! (flags & SUPPRESS)) + perror (path); + return 0; + } + + while (!feof (f)) { + if ((nread = getline (&buf, &len, f)) != -1) { + line++; + for (i = 0; i < patterns; i++) { + // FIXME: fixed pattern + if (regcomp (&re, p[i], (type == BASIC ? 0 : REG_EXTENDED) | (flags & IGNORECASE ? REG_ICASE : 0)) != 0) { + printf ("Bad regex: %s\n", p[i]); + exit(2); + } else if (regexec (&re, buf, 1, pmatch, 0) == (flags & INVERT ? REG_NOMATCH : 0)) { + if (!(flags & WHOLELINE) || (flags & WHOLELINE && pmatch[0].rm_so == 0 && pmatch[0].rm_eo == nread - 1)) { + count++; + if (NORMAL == display) { + if (flags & FILENAMES) printf ("%s:", path); + if (flags & LINENUMBERS) printf ("%d:", line); + fwrite (buf, sizeof(char), nread, stdout); + } + } + } + regfree (&re); + } + if (buf != NULL) { free (buf); buf = NULL; } + len = 0; + } + } + + if (strcmp ("-", path)) + fclose (f); + + if (count > 0 && LIST == display) { + if (strcmp ("-", path)) + printf ("%s\n", path); + else + printf ("(standard input)\n"); + } else if (COUNT == display) { + if (flags & FILENAMES) printf ("%s:", path); + printf ("%d\n", count); + } + + return count; +} + +int +main (int argc, char **argv) +{ + int c; + int n = 10; + int showname = 0; + char *end; + int type = BASIC; + int display = NORMAL; + int flags = 0; + int patterns = 0; + int pfiles = 0; + char *p[ARG_MAX]; + char *pf[ARG_MAX]; + int found = 0; + + while ((c = getopt (argc, argv, ":EFclqinsvxe:f:")) != -1) { + switch (c) { + case 'E': + type = EXTENDED; + break; + case 'F': + type = FIXED; // FIXME + break; + case 'c': + display = COUNT; + break; + case 'e': + p[patterns++] = optarg; + break; + case 'f': + pf[pfiles++] = optarg; + break; + case 'i': + flags |= IGNORECASE; + break; + case 'l': + display = LIST; + break; + case 'n': + flags |= LINENUMBERS; + break; + case 'q': + display = QUIET; + break; + case 's': + flags |= SUPPRESS; + break; + case 'v': + flags |= INVERT; + break; + case 'x': + flags |= WHOLELINE; + break; + default: + fprintf (stderr, "Usage: %s\n", grep_inv); + return 2; + } + } + + if (pfiles > 0) { + // FIXME: read in the files + } + + if (patterns == 0 && optind >= argc) { + return 2; + } else if (patterns == 0) + p[patterns++] = argv[optind++]; + + if (optind >= argc) + found = grep (patterns, p, type, display, flags, "-"); + else { + if (argc - optind > 1) flags |= FILENAMES; + while (optind < argc) + found += grep (patterns, p, type, display, flags, argv[optind++]); + } + + return (found == 0 ? 1 : 0); +} + |