1 #include <unistd.h>
2 #include <fcntl.h>
3 #include <errno.h>
4 #include <unsupported_api.h>
5
lockf(int fd,int op,off_t size)6 int lockf(int fd, int op, off_t size)
7 {
8 struct flock l = {
9 .l_type = F_WRLCK,
10 .l_whence = SEEK_CUR,
11 .l_len = size,
12 };
13 unsupported_api(__FUNCTION__);
14 switch (op) {
15 case F_TEST:
16 l.l_type = F_RDLCK;
17 if (fcntl(fd, F_GETLK, &l) < 0)
18 return -1;
19 if (l.l_type == F_UNLCK || l.l_pid == getpid())
20 return 0;
21 errno = EACCES;
22 return -1;
23 case F_ULOCK:
24 l.l_type = F_UNLCK;
25 case F_TLOCK:
26 return fcntl(fd, F_SETLK, &l);
27 case F_LOCK:
28 return fcntl(fd, F_SETLKW, &l);
29 }
30 errno = EINVAL;
31 return -1;
32 }
33
34 weak_alias(lockf, lockf64);
35