listen(2) System Calls Manual listen(2) listen - Standard C library (libc, -lc) #include int listen(int sockfd, int backlog); listen() , sockfd , , accept(2). sockfd , SOCK_STREAM SOCK_SEQPACKET. backlog , sockfd. , , ECONNREFUSED , , , . 0. -1, errno . EADDRINUSE . EADDRINUSE ( ) , sockfd, , , . /proc/sys/net/ipv4/ip_local_port_range ip(7). EBADF sockfd . ENOTSOCK sockfd . EOPNOTSUPP listen(). POSIX.1-2008. POSIX.1-2001, 4.4BSD ( 4.2BSD). : (1) socket(2). (2) bind(2) , connect(2). (3) listen(). (4) accept(2). backlog TCP- Linux 2.2. (completely) , , . /proc/sys/net/ipv4/tcp_max_syn_backlog. syncookies, . . tcp(7). backlog /proc/sys/net/core/somaxconn, . Linux 5.4, 4096; 128. Linux 2.4.25 SOMAXCONN 128. . bind(2). accept(2), bind(2), connect(2), socket(2), socket(7) () Artyom Kunyov , Azamat Hackimov , Dmitry Bolkhovskikh , Katrin Kutepova , Konstantin Shvaykovskiy , Yuri Kozlov , Kirill Rekhov ; GNU (GNU General Public License - GPL, 3 ) , - . - , , () () () <>. Linux man-pages 6.12 23 2024 . listen(2)