SHUTDOWN(2) OpenBSD Programmer's Manual SHUTDOWN(2)NAMEshutdown - disable sends or receives on a socket
SYNOPSIS
#include <sys/types.h>
#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:
SHUT_RD Further receives will be disallowed.
SHUT_WR Further sends will be disallowed. This may cause
actions specific to the protocol family of the socket
s to happen.
SHUT_RDWR Further sends and receives will be disallowed.
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
PF_INET SOCK_DGRAM IPPROTO_UDP Return 0. ICMP messages
will not be generated.
PF_INET SOCK_STREAM IPPROTO_TCP Return 0. Send queued
data, wait for ACK, then
send FIN.
PF_INET6 SOCK_DGRAM IPPROTO_UDP Return 0. ICMP messages
will not be generated.
PF_INET6 SOCK_STREAM IPPROTO_TCP Return 0. Send queued
data, wait for ACK, then
send FIN.
RETURN VALUES
The shutdown() function returns the value 0 if successful; 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 ALSOconnect(2), socket(2), inet(4), inet6(4)HISTORY
The shutdown() function call appeared in 4.2BSD. The SHUT_RD, SHUT_WR,
and SHUT_RDWR constants appeared in IEEE Std 1003.1g-2000 (``POSIX'').
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.
OpenBSD 4.9 May 31, 2007 OpenBSD 4.9
