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SHUTDOWN(2) | System Calls Manual | SHUTDOWN(2) |
NAME¶
shutdown — disable sends and/or receives on a socketLIBRARY¶
Standard C Library (libc, -lc)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. 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; see IMPLEMENTATION NOTES.
SHUT_RDWR
- Further sends and receives will be disallowed. Implies
SHUT_WR
.
SOCK_STREAM
socket, all or part of the full-duplex
connection will be shut down.
IMPLEMENTATION NOTES¶
The following protocol specific actions apply to the use ofSHUT_WR
(and potentially also
SHUT_RDWR
), 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_SCTP |
Return -1. The global variable
errno will be set to
EOPNOTSUPP . |
PF_INET |
SOCK_DGRAM |
IPPROTO_UDP |
Return 0. ICMP messages will not be generated. |
PF_INET |
SOCK_STREAM |
IPPROTO_SCTP |
Return 0. Send queued data and tear down association. |
PF_INET |
SOCK_STREAM |
IPPROTO_TCP |
Return 0. Send queued data, wait for ACK, then send FIN. |
PF_INET6 |
SOCK_DGRAM |
IPPROTO_SCTP |
Return -1. The global variable
errno will be set to
EOPNOTSUPP . |
PF_INET6 |
SOCK_DGRAM |
IPPROTO_UDP |
Return 0. ICMP messages will not be generated. |
PF_INET6 |
SOCK_STREAM |
IPPROTO_SCTP |
Return 0. Send queued data and tear down association. |
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.
- [
EOPNOTSUPP
] - The socket associated with the file descriptor s does not support this operation.
- [
ENOTCONN
] - The s argument specifies a
SOCK_STREAM
socket which is not connected. - [
ENOTSOCK
] - The s argument does not refer to a socket.
SEE ALSO¶
connect(2), socket(2), inet(4), inet6(4)STANDARDS¶
The shutdown() system call is expected to comply with IEEE Std 1003.1g-2000 (“POSIX.1g”), when finalized.HISTORY¶
The shutdown() system call appeared in 4.2BSD. TheSHUT_RD
,
SHUT_WR
, and SHUT_RDWR
constants appeared in IEEE Std 1003.1g-2000
(“POSIX.1g”).
AUTHORS¶
This manual page was updated by Bruce M. Simpson ⟨bms@FreeBSD.org⟩ to reflect how shutdown() behaves withPF_INET
and
PF_INET6
sockets.
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.March 5, 2007 | Debian |