.\" Copyright, the authors of the Linux man-pages project
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
.\"
.TH sockaddr_in 3type 2025-11-25 "Linux man-pages 6.18"
.SH NAME
sockaddr_in,
in_addr, in_addr_t, in_port_t
\-
IPv4 socket address
.SH LIBRARY
Standard C library
.RI ( libc )
.SH SYNOPSIS
.EX
.B #include <netinet/in.h>
.P
.B struct sockaddr_in {
.BR "    sa_family_t     sin_family;" "     /* " AF_INET " */"
.BR "    in_port_t       sin_port;" "       /* Port number */"
.BR "    struct in_addr  sin_addr;" "       /* IPv4 address */"
.B };
.P
.B struct in_addr {
.B "    in_addr_t s_addr;"
.B };
.P
.B typedef uint32_t in_addr_t;
.B typedef uint16_t in_port_t;
.EE
.SH DESCRIPTION
.TP
.I sockaddr_in
Describes an IPv4 Internet domain socket address.
.IP
.I .sin_port
and
.I .sin_addr
are stored in network byte order.
.SH STANDARDS
POSIX.1-2024.
.SH HISTORY
POSIX.1-2001.
.SH SEE ALSO
.BR sockaddr (3type),
.BR sockaddr_in6 (3type)