shutdown — shut down part of a full-duplex connection
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 appropriately.
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.
Conforming to
POSIX.1-2001, POSIX.1-2008, 4.4BSD (shutdown() 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
Colophon
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Referenced By
close(2), iv_fd_pump(3), lsof(1), recv(2), send(2), signal-safety(7), slirp4netns(1), socat(1), sock_diag(7), socket(2), socket(7), socketcall(2), syscalls(2), systemd.socket(5).