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

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