LXR toybox/toys/posix/cmp.c

   1/* cmp.c - Compare two files.
   2 *
   3 * Copyright 2012 Timothy Elliott <tle@holymonkey.com>
   4 *
   5 * See http://opengroup.org/onlinepubs/9699919799/utilities/cmp.html
   6
   7USE_CMP(NEWTOY(cmp, "<2>2ls[!ls]", TOYFLAG_USR|TOYFLAG_BIN))
   8
   9config CMP
  10  bool "cmp"
  11  default y
  12  help
  13    usage: cmp [-l] [-s] FILE1 FILE2
  14
  15    Compare the contents of two files.
  16
  17    -l  show all differing bytes
  18    -s  silent
  19*/
  20
  21#define FOR_cmp
  22#include "toys.h"
  23
  24GLOBALS(
  25  int fd;
  26  char *name;
  27)
  28
  29// This handles opening the file and
  30
  31static void do_cmp(int fd, char *name)
  32{
  33  int i, len1, len2, min_len, size = sizeof(toybuf)/2;
  34  long byte_no = 1, line_no = 1;
  35  char *buf2 = toybuf+size;
  36
  37  // First time through, cache the data and return.
  38  if (!TT.fd) {
  39    TT.name = name;
  40    // On return the old filehandle is closed, and this assures that even
  41    // if we were called with stdin closed, the new filehandle != 0.
  42    TT.fd = dup(fd);
  43    return;
  44  }
  45
  46  toys.exitval = 0;
  47
  48  for (;;) {
  49    len1 = readall(TT.fd, toybuf, size);
  50    len2 = readall(fd, buf2, size);
  51
  52    min_len = len1 < len2 ? len1 : len2;
  53    for (i=0; i<min_len; i++) {
  54      if (toybuf[i] != buf2[i]) {
  55        toys.exitval = 1;
  56        if (toys.optflags & FLAG_l)
  57          printf("%ld %o %o\n", byte_no, toybuf[i], buf2[i]);
  58        else {
  59          if (!(toys.optflags & FLAG_s)) 
  60            printf("%s %s differ: char %ld, line %ld\n",
  61              TT.name, name, byte_no, line_no);
  62          goto out;
  63        }
  64      }
  65      byte_no++;
  66      if (toybuf[i] == '\n') line_no++;
  67    }
  68    if (len1 != len2) {
  69      if (!(toys.optflags & FLAG_s))
  70        fprintf(stderr, "cmp: EOF on %s\n", len1 < len2 ? TT.name : name);
  71      toys.exitval = 1;
  72      break;
  73    }
  74    if (len1 < 1) break;
  75  }
  76out:
  77  if (CFG_TOYBOX_FREE) close(TT.fd);
  78}
  79
  80void cmp_main(void)
  81{
  82  toys.exitval = 2;
  83  loopfiles_rw(toys.optargs, O_CLOEXEC|(WARN_ONLY*!(toys.optflags&FLAG_s)), 0,
  84    do_cmp);
  85}
  86
  87