Creating Sockets

The socket() call creates a socket in the specified family and of the specified type.

s = socket(family, type, protocol);

If the protocol is unspecified (a value of 0), the system selects a protocol that supports the requested socket type. The socket handle (a file descriptor) is returned.

The family is specified by one of the constants defined in sys/socket.h. Constants named AF_ suite specify the address format to use in interpreting names. For more information, see the socket(3C) man page.

The following creates a datagram socket for intrasystem use:

s = socket(AF_UNIX, SOCK_DGRAM, 0);

Set the protocol argument to 0, the default protocol, in most situations.