sockaddr_in(3type) sockaddr_in(3type)

sockaddr_in, in_addr, in_addr_t, in_port_t - IPv4 socket address

Standard C library (libc)

#include <netinet/in.h>
struct sockaddr_in {
    sa_family_t     sin_family;     /* AF_INET */
    in_port_t       sin_port;       /* Port number */
    struct in_addr  sin_addr;       /* IPv4 address */
};
struct in_addr {
    in_addr_t s_addr;
};
typedef uint32_t in_addr_t;
typedef uint16_t in_port_t;

Describes an IPv4 Internet domain socket address.
.sin_port and .sin_addr are stored in network byte order.

POSIX.1-2024.

POSIX.1-2001.

sockaddr(3type), sockaddr_in6(3type)

2025-11-25 Linux man-pages (unreleased)