NAME

shutdown - shut down part of a full-duplex connection

LIBRARY

Standard C library (libc, -lc)

SYNOPSIS

#include <sys/socket.h>

int shutdown(int sockfd, int how);

DESCRIPTION

The shutdown() call causes all or part of a full-duplex connection on the socket associated with sockfd to be shut down. If how is SHUT_RD, further receptions will be disallowed. If how is SHUT_WR, further transmissions will be disallowed. If how is SHUT_RDWR, further receptions and transmissions will be disallowed.

RETURN VALUE

On success, zero is returned. On error, -1 is returned, and errno is set to indicate the error.

ERRORS

EBADF

sockfd is not a valid file descriptor.

EINVAL

An invalid value was specified in how (but see BUGS).

ENOTCONN

The specified socket is not connected.

ENOTSOCK

The file descriptor sockfd does not refer to a socket.

STANDARDS

POSIX.1-2008.

HISTORY

POSIX.1-2001, 4.4BSD (first appeared in 4.2BSD).

NOTES

The constants SHUT_RD, SHUT_WR, SHUT_RDWR have the value 0, 1, 2, respectively, and are defined in <sys/socket.h> since glibc-2.1.91.

BUGS

Checks for the validity of how are done in domain-specific code, and before Linux 3.7 not all domains performed these checks. Most notably, UNIX domain sockets simply ignored invalid values. This problem was fixed for UNIX domain sockets in Linux 3.7.

SEE ALSO

close(2), connect(2), socket(2), socket(7)