Using Unix Sockets

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

int socket(int domain, int type, int protocol);
int bind(int sockfd, const struct sockaddr *addr, socklen_t addrlen);
ssize_t sendto(int sockfd, const void *buf, size_t len, int flags, const struct sockaddr *dest_addr, socklen_t addrlen);
ssize_t recvfrom(int sockfd, void *buf, size_t len, int flags, struct sockaddr *src_addr, socklen_t *addrlen);

• socket() creates an endpoint for communication and returns a file descriptor that refers to that endpoint.

  • domain determines the protocol family which will be used: AF_UNIX, AF_LOCAL, AF_INET.

  • type determines the communication semantics: SOCK_STREAM or SOCK_DGRAM.

• When a socket is created with socket(), it exists in a name space (address space) but has no address assigned to it.

• bind() assigns the address specified in addr to the socket referred to by the file descriptor sockfd returned by the socket() method.

• sockaddr has the following structure:

struct sockaddr {
   sa_family_t sa_family;
   char sa_data[14];
}