SOCKET(1)                                                     General Commands Manual                                                    SOCKET(1)

NAME

       socket - create a TCP or a UNIX domain socket and connect to stdin/out

SYNOPSIS

       socket [ -bcfqrvw ] [ -p command ] [ -B local address ] host port
       socket [ -bcfqrvw ] [ -p command ] /path
       socket [ -bcfqrvw ] [ -p command ] [ -B local address ] -s [ -l ] port
       socket [ -bcfqrvw ] [ -p command ] -s [ -l ] /path

DESCRIPTION

       Socket  creates  an  Internet  domain  TCP or a UNIX domain stream socket and connects it to stdin and stdout.  The host argument can be an
       Internet number in dot-notation (like ``130.149.28.10'') or a domain name. In this case it must be possible to resolve the name to a  valid
       Internet  address  with gethostbyname(3).  The port argument can be a port number or a service name which can be mapped to a port number by
       getservbyname(3).  If an UNIX domain socket is wanted to be created instead of an Internet socket, specify the path instead of an  internet
       (canonical domain named or dot-notated) host.  The hostname is treated as a pathname if contains at least a single slash. I.e. if one wants
       to create or connect to a socket in the current directory, use ./filename to specify the connection point.

OPTIONS

       -b (background)
              The program forks itself into the background, detaches from its controlling tty, closes the file  descriptors  associated  with  the
              tty, and changes its current directory to the root directory.

       -B (local address)
              This option specifies which local address to binded to when making a connection.

       -c (crlf)
              Linefeed  characters  (LF)  are  converted to a Carriage Return Linefeed sequence (CRLF) when written to the socket.  CRLF sequences
              read from the socket are converted to a single LF.

       -f (fork)
              When a server connection has been accepted, a separate process is forked to handle the connection in background.

       -l (loop)
              (only valid with -s) After a connection has been closed, another connection is accepted.

       -p (program)
              The specified command is executed for each connection. Its standard input, standard output, and standard  error  channels  are  con-
              nected to the socket.  Command can be any shell command since it is passed to /bin/sh.

       -q (quit)
              The connection is closed when an end-of-file condition occurs on standard input.

       -r (read only)
              No data is read from standard input and written to the socket.

       -s (server)
              A  server  socket  is  created.   A  hostname  argument  is not required of Internet sockets, only the port number but a pathname is
              required for UNIX domain sockets.

       -v (verbose)
              Messages about connections etc. are issued to stderr.

       -w (write only)
              No data is read from the socket and written to the standard output.

       -version
              Socket prints its version ID and terminates.  This must be the first argument to have an effect.

EXAMPLES

       The command

              socket -v coma.cs.tu-berlin.de nntp

       connects to the nntp port (port 119) of coma.cs.tu-berlin.de (130.149.28.10).
       The command

              socket -sl 3425

       creates a server socket on port 3425 on the local host and waits for a connection.  After a connection has been closed, a new connection is
       accepted.
       The command

              socket -wslqvp "echo Socket! " 1938

       creates  a server socket on port 1938 on the local host and waits for a connection.  When a connection is accepted, the string "Socket!" is
       written to the socket.  No data is read from the socket and written to the finger program.  The connection is closed  when  an  end-of-file
       condition at the standard output of the program  occurs.  Then a new connection is accepted.

DIAGNOSTICS

       Lots of diagnostics for failed system calls.

       unknown host host
              host's address could not be resolved.

       Signal signal caught, exiting
              Socket exits on any signal other than SIGTSTP, SIGCONT, SIGCLD, SIGQUIT.

       A non-zero exit code is returned if socket terminates due to an error condition or a signal.

SEE ALSO

       ip(7), tcp(7), unix(7), accept(2), bind(2), listen(2), connect(2), socket(2), gethostbyname(3), getservbyname(3)

BUGS

       socket -p terminates due to a SIGPIPE signal when there is more data from the socket available than the executed program wants to read.

       Please report any other bugs to the author.

VERSION

       This manual page describes Socket-1.1.

AUTHOR

       Juergen Nickelsen <nickel@cs.tu-berlin.de>

                                                                   Aug  6, 1992                                                          SOCKET(1)