diplodocus.org Git - nmh/blob - docs/historical/mh-6.8.5/sbr/fdcompare.c

   1 /* fdcompare.c - are two files identical? */
   2 #ifndef lint
   3 static char Id[] = "@(#)$Id: fdcompare.c,v 1.4 1993/08/25 18:29:28 jromine Exp $";
   4 #endif
   5
   6 #include "../h/mh.h"
   7 #include <stdio.h>
   8 #include <sys/types.h>  /* for off_t */
   9
  10 off_t lseek();
  11
  12
  13 fdcompare (fd1, fd2)
  14 register int fd1,
  15              fd2;
  16 {
  17     register int    i,
  18                     n1,
  19                     n2,
  20                     resp;
  21     register char  *c1,
  22                    *c2;
  23     char    b1[BUFSIZ],
  24             b2[BUFSIZ];
  25
  26     resp = 1;
  27     while ((n1 = read (fd1, b1, sizeof b1)) >= 0
  28             && (n2 = read (fd2, b2, sizeof b2)) >= 0
  29             && n1 == n2) {
  30         c1 = b1;
  31         c2 = b2;
  32         for (i = n1 < sizeof b1 ? n1 : sizeof b1; i--;)
  33             if (*c1++ != *c2++) {
  34                 resp = 0;
  35                 goto leave;
  36             }
  37         if (n1 < sizeof b1)
  38             goto leave;
  39     }
  40     resp = 0;
  41
  42 leave: ;
  43     (void) lseek (fd1, (off_t)0, 0);
  44     (void) lseek (fd2, (off_t)0, 0);
  45     return resp;
  46 }