oracular (3) unix_sockets.3tcl.gz

NAME

       unix_sockets - Communicate using unix domain sockets

SYNOPSIS

       unix_sockets::listen path accept_handler
       unix_sockets::connect path

DESCRIPTION

       Unix domain sockets are a filesystem based IPC mechanism similar to IP sockets, except that they can only
       be used by processes on the same system.  This package provides a wrapper to use them from Tcl scripts.

       unix_sockets::listen path accept_handler
              Open a listening socket with the path path.  If path already exists, it is  unlinked  first.   You
              must  have  permission  to  create  path  in it's parent directory.  When a client connects to the
              listening socket, accept_handler is invoked with the channel handle of the new  client  connection
              appended.

       unix_sockets::connect path
              Connect  as  a  client  to  the unix domain socket path.  The channel handle for the new socket is
              returned.

EXAMPLE

       A simple server that echos back to the client the first line it sends, then closes the socket:

              proc readable {con} {
                  set msg [gets $con]
                  puts $con $msg
                  close $con
              }

              proc accept {con} {
                  chan event $con readable [list readable $con]
              }

              set listen   [unix_sockets::listen /tmp/example.socket accept]

              vwait ::forever

       A client that opens a socket, writes a line to it, waits for a response and exits:

              proc readable {con} {
                  set msg [gets $con]
                  puts "got response: ($msg)"
                  set ::done 1
              }

              set con     [unix_sockets::connect /tmp/example.socket]
              puts $con "hello, world"
              flush $con
              chan event $con readable [list readable $con]
              vwait ::done

SEE ALSO

       close(n), chan(n), socket(n), read(n), puts(n), eof(n), fblocked(n), flush(n)

KEYWORDS

       socket, channel, unix, ipc