|SOCKET(3P)||POSIX Programmer's Manual||SOCKET(3P)|
int socket(int domain, int type, int protocol);
The socket() function takes the following arguments:
- Specifies the communications domain in which a socket is to be created.
- Specifies the type of socket to be created.
- Specifies a particular protocol to be used with the socket. Specifying a protocol of 0 causes socket() to use an unspecified default protocol appropriate for the requested socket type.
The domain argument specifies the address family used in the communications domain. The address families supported by the system are implementation-defined.
Symbolic constants that can be used for the domain argument are defined in the <sys/socket.h> header.
The type argument specifies the socket type, which determines the semantics of communication over the socket. The following socket types are defined; implementations may specify additional socket types:
- Provides sequenced, reliable, bidirectional, connection-mode byte streams, and may provide a transmission mechanism for out-of-band data.
- Provides datagrams, which are connectionless-mode, unreliable messages of fixed maximum length.
Provides sequenced, reliable, bidirectional, connection-mode transmission paths for records. A record can be sent using one or more output operations and received using one or more input operations, but a single operation never transfers part of more than one record. Record boundaries are visible to the receiver via the MSG_EOR flag.
If the protocol argument is non-zero, it shall specify a protocol that is supported by the address family. If the protocol argument is zero, the default protocol for this address family and type shall be used. The protocols supported by the system are implementation-defined.
The process may need to have appropriate privileges to use the socket() function or to create some sockets.
The implementation does not support the specified address family.
- All file descriptors available to the process are currently open.
- No more file descriptors are available for the system.
The protocol is not supported by the address family, or the protocol is not supported by the implementation.
- The socket type is not supported by the protocol.
The socket() function may fail if:
- The process does not have appropriate privileges.
- Insufficient resources were available in the system to perform the operation.
- Insufficient memory was available to fulfill the request.
The following sections are informative.
The application can determine whether an address family is supported by trying to create a socket with domain set to the protocol in question.
The Base Definitions volume of POSIX.1‐2017, <netinet_in.h>, <sys_socket.h>
Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .
|2017||IEEE/The Open Group|