setsockopt()

Updated: May 06, 2022

Set options associated with a socket

Synopsis:

#include <sys/types.h>
#include <sys/socket.h>

int setsockopt( int s,
                int level,
                int optname, 
                const void * optval,
                socklen_t optlen );

Arguments:

s
The file descriptor of the socket that the option is to be applied on, as returned by socket().
level
The protocol layer that the option is to be applied to. In most cases, it's a socket-level option and is indicated by SOL_SOCKET.
optname
The option for the socket file descriptor.
optval
A pointer to the value that you want to set the option to. In most cases, the value indicates whether the option is to be turned on (nonzero) or off (zero).

Most socket-level options use an int parameter for optval. Others, such as the SO_LINGER, SO_SNDTIMEO, and SO_RCVTIMEO options, use structures that also let you get data associated with the option.

optlen
The length of the value for the option, in bytes.

Library:

libsocket

Use the -l socket option to qcc to link against this library.

Description:

The setsockopt() function sets the options associated with a socket. See getsockopt() for more detailed information.

Returns:

0
Success.
-1
An error occurred (errno is set).

Errors:

EBADF
Invalid file descriptor s.
EDOM
Value was set out of range.
EFAULT
The address pointed to by optval isn't in a valid part of the process address space.
EINVAL
No optval value was specified, or the size of the value is invalid.
ENOPROTOOPT
The option is unknown at the level indicated.
EOPNOTSUPP
You tried to set the SO_TXPRIO option, but you didn't specify the so_txprio_enable option when you started io-pkt.

Classification:

POSIX 1003.1

Safety:  
Cancellation point No
Interrupt handler No
Signal handler Yes
Thread Yes