GeezerVison

NAME

shutdown — disable sends or receives on a socket

SYNOPSIS

#include <sys/socket.h>

int
shutdown(int s, int how);

DESCRIPTION

The shutdown() system call disables sends or receives on a socket.

If the file descriptor s is associated with a SOCK_STREAM socket, all or part of the full-duplex connection will be shut down.

The how argument specifies the type of shutdown. Possible values are:

The following protocol specific actions apply to the use of SHUT_WR based on the properties of the socket associated with the file descriptor s:

RETURN VALUES

Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and the global variable errno is set to indicate the error.

ERRORS

The shutdown() system call fails if:

[EBADF]

The s argument is not a valid file descriptor.

[EINVAL]

The how argument is invalid.

[ENOTCONN]

The s argument specifies a SOCK_STREAM socket which is not connected.

[ENOTSOCK]

The s argument does not refer to a socket.

[EOPNOTSUPP]

The socket associated with the file descriptor s does not support this operation.

SEE ALSO

connect(2), socket(2), inet(4), inet6(4)

STANDARDS

The shutdown() function conforms to IEEE Std 1003.1-2008 (“POSIX.1”).

HISTORY

The shutdown() system call first appeared in 4.1cBSD. The SHUT_RD, SHUT_WR, and SHUT_RDWR constants appeared in IEEE Std 1003.1g-2000 (“POSIX.1g”).

BUGS

The ICMP “port unreachable” message should be generated in response to datagrams received on a local port to which s is bound after shutdown() is called.