NAME
shutdown
—
disable sends or receives on a
socket
SYNOPSIS
#include
<sys/socket.h>
int
shutdown
(int
s, int how);
DESCRIPTION
Theshutdown
()
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:
DOMAIN | TYPE | PROTOCOL | RETURN VALUE AND ACTION |
AF_INET |
SOCK_DGRAM |
IPPROTO_UDP |
Return 0. ICMP messages will not be generated. |
AF_INET |
SOCK_STREAM |
IPPROTO_TCP |
Return 0. Send queued data, wait for ACK, then send FIN. |
AF_INET6 |
SOCK_DGRAM |
IPPROTO_UDP |
Return 0. ICMP messages will not be generated. |
AF_INET6 |
SOCK_STREAM |
IPPROTO_TCP |
Return 0. Send queued data, wait for ACK, then send FIN. |
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
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.