git.maemo.org Git - busybox4maemo/blob - coreutils/uniq.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * uniq implementation for busybox
   4  *
   5  * Copyright (C) 2005  Manuel Novoa III  <mjn3@codepoet.org>
   6  *
   7  * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
   8  */
   9
  10 /* BB_AUDIT SUSv3 compliant */
  11 /* http://www.opengroup.org/onlinepubs/007904975/utilities/uniq.html */
  12
  13 #include "libbb.h"
  14
  15 static const char uniq_opts[] ALIGN1 = "cdu" "f:s:" "cdu\0\1\2\4";
  16
  17 static FILE *xgetoptfile_uniq_s(char **argv, int read0write2)
  18 {
  19         const char *n;
  20
  21         n = *argv;
  22         if (n != NULL) {
  23                 if ((*n != '-') || n[1]) {
  24                         return xfopen(n, "r\0w" + read0write2);
  25                 }
  26         }
  27         return (read0write2) ? stdout : stdin;
  28 }
  29
  30 int uniq_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  31 int uniq_main(int argc ATTRIBUTE_UNUSED, char **argv)
  32 {
  33         FILE *in, *out;
  34         unsigned long dups, skip_fields, skip_chars, i;
  35         const char *s0, *e0, *s1, *e1, *input_filename;
  36         unsigned opt;
  37
  38         enum {
  39                 OPT_c = 0x1,
  40                 OPT_d = 0x2,
  41                 OPT_u = 0x4,
  42                 OPT_f = 0x8,
  43                 OPT_s = 0x10,
  44         };
  45
  46         skip_fields = skip_chars = 0;
  47
  48         opt = getopt32(argv, "cduf:s:", &s0, &s1);
  49         if (opt & OPT_f)
  50                 skip_fields = xatoul(s0);
  51         if (opt & OPT_s)
  52                 skip_chars = xatoul(s1);
  53         argv += optind;
  54
  55         input_filename = *argv;
  56
  57         in = xgetoptfile_uniq_s(argv, 0);
  58         if (*argv) {
  59                 ++argv;
  60         }
  61         out = xgetoptfile_uniq_s(argv, 2);
  62         if (*argv && argv[1]) {
  63                 bb_show_usage();
  64         }
  65
  66         s1 = e1 = NULL;                         /* prime the pump */
  67
  68         do {
  69                 s0 = s1;
  70                 e0 = e1;
  71                 dups = 0;
  72
  73                 /* gnu uniq ignores newlines */
  74                 while ((s1 = xmalloc_getline(in)) != NULL) {
  75                         e1 = s1;
  76                         for (i = skip_fields; i; i--) {
  77                                 e1 = skip_whitespace(e1);
  78                                 e1 = skip_non_whitespace(e1);
  79                         }
  80                         for (i = skip_chars; *e1 && i; i--) {
  81                                 ++e1;
  82                         }
  83
  84                         if (!s0 || strcmp(e0, e1)) {
  85                                 break;
  86                         }
  87
  88                         ++dups;          /* Note: Testing for overflow seems excessive. */
  89                 }
  90
  91                 if (s0) {
  92                         if (!(opt & (OPT_d << !!dups))) { /* (if dups, opt & OPT_e) */
  93                                 fprintf(out, "\0%d " + (opt & 1), dups + 1);
  94                                 fprintf(out, "%s\n", s0);
  95                         }
  96                         free((void *)s0);
  97                 }
  98         } while (s1);
  99
 100         die_if_ferror(in, input_filename);
 101
 102         fflush_stdout_and_exit(EXIT_SUCCESS);
 103 }