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TCP(3)                     Library Functions Manual                     TCP(3)



NAME
       tcp_sock, tcp_conn, tcp_listen, tcp_accept, tcp_rcmd - tcp operations

SYNOPSIS
       #include <sys/inet/tcp_user.h>

       tcp_sock();

       tcp_connect(fd, lport, faddr, fport)
       int fd;
       tcp_port lport, fport;
       in_addr faddr;

       tcp_listen(fd, lport, faddr, fport)
       int fd;
       tcp_port lport, fport;
       in_addr faddr;

       tcp_accept(fd, faddrp, fportp, devp)
       int fd, *devp;
       in_addr *faddrp;
       tcp_port *fportp;

       tcp_rcmd(host, port, locuser, remuser, cmd, fd2p)
       char *host, *port, *locuser, *remuser, *cmd;
       int *fd2p;

DESCRIPTION
       These routines are loaded by the -lin option of ld(1).

       TCP  is  one  of the many protocols which are layered upon IP (internet
       protocol).  It provides full duplex byte stream connections between end
       points  called sockets.  The address of a socket is composed of the in‐
       ternet address of its host and the port number to which the  socket  is
       bound.

       Tcp_sock  returns  the  file  descriptor  of  an  unbound socket.  Once
       opened, a socket may be bound to a port number within the host and  set
       up  as  the active or passive end of a connection.  Tcp_sock returns -1
       if no sockets are available.

       Tcp_connect binds socket fd to port lport and attempts to set up a con‐
       nection  to  the socket bound to port fport on host faddr.  Tcp_connect
       returns 0 if the connection is established, -1  otherwise.   Communica‐
       tions proceeds by performing read(2) and write(2) on fd.

       Tcp_listen  binds  socket fd to port lport and configures the socket to
       listen for connection requests to that port.  If faddr  and  fport  are
       non-zero,  only  connections  coming  from sockets on machine faddr and
       bound to port fport are listened for.  Tcp_listen returns 0 on success,
       -1 otherwise.  Select(2) can be used with a listening socket to provide
       asynchronous polling of connection requests.

       Tcp_accept waits for and accepts a connection request sent to the  lis‐
       tening socket fd.  When a connection arrives, tcp_accept fills in faddr
       and fport with the identity of the connector and returns a new fd  over
       which  communications  can proceed.  Fd is left open and continues lis‐
       tening for connections.

       Tcp_rcmd remotely executes a cmd on host as user remuser.  Standard in‐
       put  is  attached  to cmd's standard input and cmd's standard output is
       attached to standard output.  If fd2p is non-zero, it  is  filled  with
       the  fd of a new TCP connection attached to cmd's standard error.  Oth‐
       erwise, cmd's standard error is attached to its standard output.

FILES
       /dev/tcp* the socket devices

SEE ALSO
       internet(3), udp(3)



                                                                        TCP(3)