SHUTDOWN(2) Linux Programmer's Manual SHUTDOWN(2)
shutdown - shut down part of a full-duplex connection
int shutdown(int s, int how);
The shutdown() call causes all or part of a full-duplex connection on
the socket associated with s to be shut down. If how is SHUT_RD, fur-
ther receptions will be disallowed. If how is SHUT_WR, further trans-
missions will be disallowed. If how is SHUT_RDWR, further receptions
and transmissions will be disallowed.
On success, zero is returned. On error, -1 is returned, and errno is
EBADF s is not a valid descriptor.
The specified socket is not connected.
s is a file, not a socket.
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.
POSIX.1-2001, 4.4BSD (the shutdown() function call first appeared in
BSD Man Page 1993-07-24 SHUTDOWN(2)