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 } 24