GNU Info

(elisp)Network

---

Prev: Transaction Queues Up: Processes

---

Enter node , (file) or (file)node

Network Connections
===================

   Emacs Lisp programs can open TCP network connections to other
processes on the same machine or other machines.  A network connection
is handled by Lisp much like a subprocess, and is represented by a
process object.  However, the process you are communicating with is not
a child of the Emacs process, so you can't kill it or send it signals.
All you can do is send and receive data.  `delete-process' closes the
connection, but does not kill the process at the other end; that
process must decide what to do about closure of the connection.

   You can distinguish process objects representing network connections
from those representing subprocesses with the `process-status'
function.  It always returns either `open' or `closed' for a network
connection, and it never returns either of those values for a real
subprocess.  Note: Process Information.

 - Function: open-network-stream name buffer-or-name host service
     This function opens a TCP connection for a service to a host.  It
     returns a process object to represent the connection.

     The NAME argument specifies the name for the process object.  It
     is modified as necessary to make it unique.

     The BUFFER-OR-NAME argument is the buffer to associate with the
     connection.  Output from the connection is inserted in the buffer,
     unless you specify a filter function to handle the output.  If
     BUFFER-OR-NAME is `nil', it means that the connection is not
     associated with any buffer.

     The arguments HOST and SERVICE specify where to connect to; HOST
     is the host name (a string), and SERVICE is the name of a defined
     network service (a string) or a port number (an integer).