This function creates a socket and specifies communication style
style, which should be one of the socket styles listed in
Communication Styles. The namespace argument specifies
the namespace; it must be PF_LOCAL (see Local Namespace) or
PF_INET (see Internet Namespace). protocol
designates the specific protocol (see Socket Concepts); zero is
usually right for protocol.
The return value from socket is the file descriptor for the new
socket, or -1 in case of error. The following errno error
conditions are defined for this function:
EPROTONOSUPPORT- The protocol or style is not supported by the
namespace specified.
EMFILE- The process already has too many file descriptors open.
ENFILE- The system already has too many file descriptors open.
EACCES- The process does not have the privilege to create a socket of the specified
style or protocol.
ENOBUFS- The system ran out of internal buffer space.
The file descriptor returned by the socket function supports both
read and write operations. However, like pipes, sockets do not support file
positioning operations.
