LXR busybox/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 tarball for details.
   8 */
   9
  10#include "libbb.h"
  11
  12#define COMM_OPT_1 (1 << 0)
  13#define COMM_OPT_2 (1 << 1)
  14#define COMM_OPT_3 (1 << 2)
  15
  16/* writeline outputs the input given, appropriately aligned according to class */
  17static void writeline(char *line, int class)
  18{
  19        int flags = option_mask32;
  20        if (class == 0) {
  21                if (flags & COMM_OPT_1)
  22                        return;
  23        } else if (class == 1) {
  24                if (flags & COMM_OPT_2)
  25                        return;
  26                if (!(flags & COMM_OPT_1))
  27                        putchar('\t');
  28        } else /*if (class == 2)*/ {
  29                if (flags & COMM_OPT_3)
  30                        return;
  31                if (!(flags & COMM_OPT_1))
  32                        putchar('\t');
  33                if (!(flags & COMM_OPT_2))
  34                        putchar('\t');
  35        }
  36        puts(line);
  37}
  38
  39int comm_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  40int comm_main(int argc UNUSED_PARAM, char **argv)
  41{
  42        char *thisline[2];
  43        FILE *stream[2];
  44        int i;
  45        int order;
  46
  47        opt_complementary = "=2";
  48        getopt32(argv, "123");
  49        argv += optind;
  50
  51        for (i = 0; i < 2; ++i) {
  52                stream[i] = xfopen_stdin(argv[i]);
  53        }
  54
  55        order = 0;
  56        thisline[1] = thisline[0] = NULL;
  57        while (1) {
  58                if (order <= 0) {
  59                        free(thisline[0]);
  60                        thisline[0] = xmalloc_fgetline(stream[0]);
  61                }
  62                if (order >= 0) {
  63                        free(thisline[1]);
  64                        thisline[1] = xmalloc_fgetline(stream[1]);
  65                }
  66
  67                i = !thisline[0] + (!thisline[1] << 1);
  68                if (i)
  69                        break;
  70                order = strcmp(thisline[0], thisline[1]);
  71
  72                if (order >= 0)
  73                        writeline(thisline[1], order ? 1 : 2);
  74                else
  75                        writeline(thisline[0], 0);
  76        }
  77
  78        /* EOF at least on one of the streams */
  79        i &= 1;
  80        if (thisline[i]) {
  81                /* stream[i] is not at EOF yet */
  82                /* we did not print thisline[i] yet */
  83                char *p = thisline[i];
  84                writeline(p, i);
  85                while (1) {
  86                        free(p);
  87                        p = xmalloc_fgetline(stream[i]);
  88                        if (!p)
  89                                break;
  90                        writeline(p, i);
  91                }
  92        }
  93
  94        if (ENABLE_FEATURE_CLEAN_UP) {
  95                fclose(stream[0]);
  96                fclose(stream[1]);
  97        }
  98
  99        return EXIT_SUCCESS;
 100}
 101