1 /* $NetBSD: pread.c,v 1.1.1.5 2015/01/02 20:34:27 christos Exp $ */ 2 3 #include "file.h" 4 #ifndef lint 5 #if 0 6 FILE_RCSID("@(#)$File: pread.c,v 1.3 2014/09/15 19:11:25 christos Exp $") 7 #else 8 __RCSID("$NetBSD: pread.c,v 1.1.1.5 2015/01/02 20:34:27 christos Exp $"); 9 #endif 10 #endif /* lint */ 11 #include <fcntl.h> 12 #include <unistd.h> 13 14 ssize_t 15 pread(int fd, void *buf, size_t len, off_t off) { 16 off_t old; 17 ssize_t rv; 18 19 if ((old = lseek(fd, off, SEEK_SET)) == -1) 20 return -1; 21 22 if ((rv = read(fd, buf, len)) == -1) 23 return -1; 24 25 if (lseek(fd, old, SEEK_SET) == -1) 26 return -1; 27 28 return rv; 29 } 30