contrib/file/src/pread.c

   1 #include "file.h"
   2 #ifndef lint
   3 FILE_RCSID("@(#)$File: pread.c,v 1.3 2014/09/15 19:11:25 christos Exp $")
   4 #endif  /* lint */
   5 #include <fcntl.h>
   6 #include <unistd.h>
   7
   8 ssize_t
   9 pread(int fd, void *buf, size_t len, off_t off) {
  10         off_t old;
  11         ssize_t rv;
  12
  13         if ((old = lseek(fd, off, SEEK_SET)) == -1)
  14                 return -1;
  15
  16         if ((rv = read(fd, buf, len)) == -1)
  17                 return -1;
  18
  19         if (lseek(fd, old, SEEK_SET) == -1)
  20                 return -1;
  21
  22         return rv;
  23 }