1 #include "file.h"
2 #ifndef lint
3 FILE_RCSID("@(#)$File: pread.c,v 1.5 2022/09/24 20:30:13 christos Exp $")
4 #endif /* lint */
5 #include <fcntl.h>
6 #include <unistd.h>
7
8 ssize_t
pread(int fd,void * buf,size_t len,off_t off)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 }
24