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 #include "fdcompare.h"
  10
  11
  12 int
  13 fdcompare (int fd1, int fd2)
  14 {
  15     int i, n1, n2;
  16     char *c1, *c2;
  17     char b1[BUFSIZ], b2[BUFSIZ];
  18
  19     bool resp = true;
  20     while ((n1 = read (fd1, b1, sizeof(b1))) >= 0
  21             && (n2 = read (fd2, b2, sizeof(b2))) >= 0
  22             && n1 == n2) {
  23         c1 = b1;
  24         c2 = b2;
  25         for (i = n1 < (int) sizeof(b1) ? n1 : (int) sizeof(b1); i--;)
  26             if (*c1++ != *c2++) {
  27                 resp = false;
  28                 goto leave;
  29             }
  30         if (n1 < (int) sizeof(b1))
  31             goto leave;
  32     }
  33     resp = false;
  34
  35 leave: ;
  36     lseek(fd1, 0, SEEK_SET);
  37     lseek(fd2, 0, SEEK_SET);
  38     return resp;
  39 }