fix multiple stdio functions' behavior on zero-length operations
[oweals/musl.git] / src / stdio / fileno.c
1 #include "stdio_impl.h"
2
3 int fileno(FILE *f)
4 {
5         /* f->fd never changes, but the lock must be obtained and released
6          * anyway since this function cannot return while another thread
7          * holds the lock. */
8         FLOCK(f);
9         FUNLOCK(f);
10         return f->fd;
11 }
12
13 weak_alias(fileno, fileno_unlocked);