Network Inter-Process Communication
Contents
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Networked communication between devices play an important role in the running of systems.
Sure we could just copy everything onto USBs and CDs, then get them posted to our destination -
but that’s slow… or is it????
Sockets
Sockets are the method in which programs connect to programs on other devices.
The server creates a socket, binding itself to an address, and waits for connections.
The client creates a socket, connecting to the address of the server, and writes and reads from the socket
sys/socket.h provides the functionality for sockets
int socket(int Domain, int Type, int Protocol)
Domain: AF_LOCAL, AF_INET
Type: SOCK_STREAM, SOCK_DGRAM
Protocol: See etc/protocols
ret: socket descriptor, or -1 on error
int bind(int Sockfd, SockAddr *Addr, socklen_t AddrLen)
int listen(int Sockfd, int Backlog)
typedef struct sockaddr_in SockAddr.sin_family - domain.sin_port - port.sin_addr - address.sin_zero[8] - padding
int accept(int Sockfd, SockAddr *Addr, socklen_t *AddrLen)
- Blocks until connection request
- Returns new socket descriptor, or -1 on error
int connect(int Sockfd, SockAddr *Addr, socklen_t AddrLen)
- Connect to the socket
- Returns 0, or -1 on error