diplodocus.org Git - nmh/blob - sbr/fdcompare.c

   1
   2 /*
   3  * fdcompare.c -- are two files identical?
   4  *
   5  * $Id$
   6  *
   7  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   8  * COPYRIGHT file in the root directory of the nmh distribution for
   9  * complete copyright information.
  10  */
  11
  12 #include <h/mh.h>
  13
  14
  15 int
  16 fdcompare (int fd1, int fd2)
  17 {
  18     register int i, n1, n2, resp;
  19     register char *c1, *c2;
  20     char b1[BUFSIZ], b2[BUFSIZ];
  21
  22     resp = 1;
  23     while ((n1 = read (fd1, b1, sizeof(b1))) >= 0
  24             && (n2 = read (fd2, b2, sizeof(b2))) >= 0
  25             && n1 == n2) {
  26         c1 = b1;
  27         c2 = b2;
  28         for (i = n1 < sizeof(b1) ? n1 : sizeof(b1); i--;)
  29             if (*c1++ != *c2++) {
  30                 resp = 0;
  31                 goto leave;
  32             }
  33         if (n1 < sizeof(b1))
  34             goto leave;
  35     }
  36     resp = 0;
  37
  38 leave: ;
  39     lseek (fd1, (off_t) 0, SEEK_SET);
  40     lseek (fd2, (off_t) 0, SEEK_SET);
  41     return resp;
  42 }