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

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