#Name

recvfd - receive a file descriptor from a local socket peer

#Synopsis

#include <sys/socket.h>

int recvfd(int sockfd, int options);

#Description

Receive an open file descriptor from a local socket peer connected via sockfd. This is a non-blocking call that will fail if there is no file descriptor waiting in the socket's queue.

File descriptors are sent out-of-band and do not affect the regular data streams.

The options argument accepts a bitmask of the following flags:

• O_CLOEXEC: The opened fd shall be closed on exec(2).

#Return value

If a file descriptor is successfully received, it is returned as a non-negative integer. Otherwise, -1 is returned and errno is set to indicate the error.

#Errors

• EBADF: sockfd is not an open file descriptor.
• ENOTSOCK: sockfd does not refer to a socket.
• EAFNOSUPPORT: sockfd does not refer to a local domain socket.
• EINVAL: sockfd does not refer to a connected or accepted socket.
• EAGAIN: There is no file descriptor queued on this socket.

#History

recvfd() was first introduced in Plan 9 from User Space.

#See also

• sendfd(2)