coreutils/comm.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Mini comm implementation for busybox
   4  *
   5  * Copyright (C) 2005 by Robert Sullivan <cogito.ergo.cogito@gmail.com>
   6  *
   7  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   8  */
   9
  10 //usage:#define comm_trivial_usage
  11 //usage:       "[-123] FILE1 FILE2"
  12 //usage:#define comm_full_usage "\n\n"
  13 //usage:       "Compare FILE1 with FILE2\n"
  14 //usage:     "\nOptions:"
  15 //usage:     "\n        -1      Suppress lines unique to FILE1"
  16 //usage:     "\n        -2      Suppress lines unique to FILE2"
  17 //usage:     "\n        -3      Suppress lines common to both files"
  18
  19 #include "libbb.h"
  20
  21 #define COMM_OPT_1 (1 << 0)
  22 #define COMM_OPT_2 (1 << 1)
  23 #define COMM_OPT_3 (1 << 2)
  24
  25 /* writeline outputs the input given, appropriately aligned according to class */
  26 static void writeline(char *line, int class)
  27 {
  28         int flags = option_mask32;
  29         if (class == 0) {
  30                 if (flags & COMM_OPT_1)
  31                         return;
  32         } else if (class == 1) {
  33                 if (flags & COMM_OPT_2)
  34                         return;
  35                 if (!(flags & COMM_OPT_1))
  36                         putchar('\t');
  37         } else /*if (class == 2)*/ {
  38                 if (flags & COMM_OPT_3)
  39                         return;
  40                 if (!(flags & COMM_OPT_1))
  41                         putchar('\t');
  42                 if (!(flags & COMM_OPT_2))
  43                         putchar('\t');
  44         }
  45         puts(line);
  46 }
  47
  48 int comm_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  49 int comm_main(int argc UNUSED_PARAM, char **argv)
  50 {
  51         char *thisline[2];
  52         FILE *stream[2];
  53         int i;
  54         int order;
  55
  56         opt_complementary = "=2";
  57         getopt32(argv, "123");
  58         argv += optind;
  59
  60         for (i = 0; i < 2; ++i) {
  61                 stream[i] = xfopen_stdin(argv[i]);
  62         }
  63
  64         order = 0;
  65         thisline[1] = thisline[0] = NULL;
  66         while (1) {
  67                 if (order <= 0) {
  68                         free(thisline[0]);
  69                         thisline[0] = xmalloc_fgetline(stream[0]);
  70                 }
  71                 if (order >= 0) {
  72                         free(thisline[1]);
  73                         thisline[1] = xmalloc_fgetline(stream[1]);
  74                 }
  75
  76                 i = !thisline[0] + (!thisline[1] << 1);
  77                 if (i)
  78                         break;
  79                 order = strcmp(thisline[0], thisline[1]);
  80
  81                 if (order >= 0)
  82                         writeline(thisline[1], order ? 1 : 2);
  83                 else
  84                         writeline(thisline[0], 0);
  85         }
  86
  87         /* EOF at least on one of the streams */
  88         i &= 1;
  89         if (thisline[i]) {
  90                 /* stream[i] is not at EOF yet */
  91                 /* we did not print thisline[i] yet */
  92                 char *p = thisline[i];
  93                 writeline(p, i);
  94                 while (1) {
  95                         free(p);
  96                         p = xmalloc_fgetline(stream[i]);
  97                         if (!p)
  98                                 break;
  99                         writeline(p, i);
 100                 }
 101         }
 102
 103         if (ENABLE_FEATURE_CLEAN_UP) {
 104                 fclose(stream[0]);
 105                 fclose(stream[1]);
 106         }
 107
 108         return EXIT_SUCCESS;
 109 }