getty: fix for NOCTTY killing us with SIGHUP
[oweals/busybox.git] / coreutils / uniq.c
index 965d290c2ff9003e4d72707601ffb15ae36e0a4e..9208d34ec487040bf3a7c40394f910cfe618367e 100644 (file)
+/* vi: set sw=4 ts=4: */
 /*
- * Mini uniq implementation for busybox
+ * uniq implementation for busybox
  *
+ * Copyright (C) 2005  Manuel Novoa III  <mjn3@codepoet.org>
  *
- * Copyright (C) 1999 by Lineo, inc.
- * Written by John Beppu <beppu@lineo.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
- *
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 
-#include "internal.h"
-#include <stdio.h>
-#include <string.h>
-#include <errno.h>
-
-static const char uniq_usage[] =
-"uniq [OPTION]... [INPUT [OUTPUT]]\n"
-"Discard all but one of successive identical lines from INPUT (or\n"
-"standard input), writing to OUTPUT (or standard output).\n"
-"\n"
-"\t-h\tdisplay this help and exit\n"
-"\n"
-"A field is a run of whitespace, then non-whitespace characters.\n"
-"Fields are skipped before chars.\n"
-;
-
-/* max chars in line */
-#define UNIQ_MAX 4096
-
-typedef void (Print)(FILE *, const char *);
-
-typedef int (Decide)(const char *, const char *);
-
-/* container for two lines to be compared */
-typedef struct {
-    char    *a;
-    char    *b;
-    int            recurrence;
-    FILE    *in;
-    FILE    *out;
-    void    *func;
-} Subject;
-
-/* set up all the variables of a uniq operation */
-static Subject *
-subject_init(Subject *self, FILE *in, FILE *out, void *func)
-{
-    self->a    = NULL;
-    self->b    = NULL;
-    self->in   = in;
-    self->out  = out;
-    self->func = func;
-    self->recurrence = 0;
-    return self;
-}
-
-/* point a and b to the appropriate lines;
- * count the recurrences (if any) of a string;
- */
-static Subject *
-subject_next(Subject *self)
-{
-    /* tmp line holders */
-    static char line[2][UNIQ_MAX];
-    static int  alternator = 0;
-
-    if (fgets(line[alternator], UNIQ_MAX, self->in)) {
-       self->a = self->b;
-       self->b = line[alternator];
-       alternator ^= 1;
-       return self;
-    }
-
-    return NULL;
-}
-
-static Subject *
-subject_last(Subject *self)
-{
-    self->a = self->b;
-    self->b = NULL;
-    return self;
-}
-
-static Subject *
-subject_study(Subject *self)
-{
-    if (self->a == NULL) {
-       return self;
-    }
-    if (self->b == NULL) {
-       fprintf(self->out, "%s", self->a);
-       return self;
-    }
-    if (strcmp(self->a, self->b) == 0) {
-       self->recurrence++;
-    } else {
-       fprintf(self->out, "%s", self->a);
-       self->recurrence = 0;
-    }
-    return self;
-}
-
-static int
-set_file_pointers(int schema, FILE **in, FILE **out, char **argv)
+/* BB_AUDIT SUSv3 compliant */
+/* http://www.opengroup.org/onlinepubs/007904975/utilities/uniq.html */
+
+//usage:#define uniq_trivial_usage
+//usage:       "[-cdu][-f,s,w N] [INPUT [OUTPUT]]"
+//usage:#define uniq_full_usage "\n\n"
+//usage:       "Discard duplicate lines\n"
+//usage:     "\n       -c      Prefix lines by the number of occurrences"
+//usage:     "\n       -d      Only print duplicate lines"
+//usage:     "\n       -u      Only print unique lines"
+//usage:     "\n       -f N    Skip first N fields"
+//usage:     "\n       -s N    Skip first N chars (after any skipped fields)"
+//usage:     "\n       -w N    Compare N characters in line"
+//usage:
+//usage:#define uniq_example_usage
+//usage:       "$ echo -e \"a\\na\\nb\\nc\\nc\\na\" | sort | uniq\n"
+//usage:       "a\n"
+//usage:       "b\n"
+//usage:       "c\n"
+
+#include "libbb.h"
+
+int uniq_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int uniq_main(int argc UNUSED_PARAM, char **argv)
 {
-    switch (schema) {
-       case 0:
-           *in = stdin;
-           *out = stdout;
-           break;
-       case 1:
-           *in = fopen(argv[0], "r");
-           *out = stdout;
-           break;
-       case 2:
-           *in = fopen(argv[0], "r");
-           *out = fopen(argv[1], "w");
-           break;
-    }
-    if (*in == NULL) {
-       fprintf(stderr, "uniq: %s: %s\n", argv[0], strerror(errno));
-       return errno;
-    }
-    if (*out == NULL) {
-       fprintf(stderr, "uniq: %s: %s\n", argv[1], strerror(errno));
-       return errno;
-    }
-    return 0;
-}
-
-
-/* one variable is the decision algo */
-/* another variable is the printing algo */
-
-/* I don't think I have to have more than a 1 line memory 
-   this is the one constant */
-
-/* it seems like GNU/uniq only takes one or two files as an option */
-
-/* ________________________________________________________________________ */
-int
-uniq_main(int argc, char **argv)
-{
-    int            i;
-    char    opt;
-    FILE    *in, *out;
-    Subject s;
-
-    /* parse argv[] */
-    for (i = 1; i < argc; i++) {
-       if (argv[i][0] == '-') {
-           opt = argv[i][1];
-           switch (opt) {
-               case '-':
-               case 'h':
-                   usage(uniq_usage);
-               default:
-                   usage(uniq_usage);
-           }
-       } else {
-           break;
+       const char *input_filename;
+       unsigned skip_fields, skip_chars, max_chars;
+       unsigned opt;
+       char *cur_line;
+       const char *cur_compare;
+
+       enum {
+               OPT_c = 0x1,
+               OPT_d = 0x2, /* print only dups */
+               OPT_u = 0x4, /* print only uniq */
+               OPT_f = 0x8,
+               OPT_s = 0x10,
+               OPT_w = 0x20,
+       };
+
+       skip_fields = skip_chars = 0;
+       max_chars = INT_MAX;
+
+       opt_complementary = "f+:s+:w+";
+       opt = getopt32(argv, "cduf:s:w:", &skip_fields, &skip_chars, &max_chars);
+       argv += optind;
+
+       input_filename = argv[0];
+       if (input_filename) {
+               const char *output;
+
+               if (input_filename[0] != '-' || input_filename[1]) {
+                       close(STDIN_FILENO); /* == 0 */
+                       xopen(input_filename, O_RDONLY); /* fd will be 0 */
+               }
+               output = argv[1];
+               if (output) {
+                       if (argv[2])
+                               bb_show_usage();
+                       if (output[0] != '-' || output[1]) {
+                               // Won't work with "uniq - FILE" and closed stdin:
+                               //close(STDOUT_FILENO);
+                               //xopen(output, O_WRONLY | O_CREAT | O_TRUNC);
+                               xmove_fd(xopen(output, O_WRONLY | O_CREAT | O_TRUNC), STDOUT_FILENO);
+                       }
+               }
        }
-    }
-
-    /* 0 src: stdin; dst: stdout */
-    /* 1 src: file;  dst: stdout */
-    /* 2 src: file;  dst: file   */
-    if (set_file_pointers((argc - 1), &in, &out, &argv[i])) {
-       exit(1);
-    }
-
-    subject_init(&s, in, out, NULL);
-    while (subject_next(&s)) { 
-       subject_study(&s);
-    }
-    subject_last(&s);
-    subject_study(&s);
-
-    exit(0);
-}
 
-/* $Id: uniq.c,v 1.6 2000/02/07 05:29:42 erik Exp $ */
+       cur_compare = cur_line = NULL; /* prime the pump */
+
+       do {
+               unsigned i;
+               unsigned long dups;
+               char *old_line;
+               const char *old_compare;
+
+               old_line = cur_line;
+               old_compare = cur_compare;
+               dups = 0;
+
+               /* gnu uniq ignores newlines */
+               while ((cur_line = xmalloc_fgetline(stdin)) != NULL) {
+                       cur_compare = cur_line;
+                       for (i = skip_fields; i; i--) {
+                               cur_compare = skip_whitespace(cur_compare);
+                               cur_compare = skip_non_whitespace(cur_compare);
+                       }
+                       for (i = skip_chars; *cur_compare && i; i--) {
+                               ++cur_compare;
+                       }
+
+                       if (!old_line || strncmp(old_compare, cur_compare, max_chars)) {
+                               break;
+                       }
+
+                       free(cur_line);
+                       ++dups;  /* testing for overflow seems excessive */
+               }
+
+               if (old_line) {
+                       if (!(opt & (OPT_d << !!dups))) { /* (if dups, opt & OPT_u) */
+                               if (opt & OPT_c) {
+                                       /* %7lu matches GNU coreutils 6.9 */
+                                       printf("%7lu ", dups + 1);
+                               }
+                               printf("%s\n", old_line);
+                       }
+                       free(old_line);
+               }
+       } while (cur_line);
+
+       die_if_ferror(stdin, input_filename);
+
+       fflush_stdout_and_exit(EXIT_SUCCESS);
+}