PATCH: TCP example

[Peter Stephenson <pws@xxxxxxx>]

This adds an example to the documentation for the tcp module.

Index: Doc/Zsh/mod_tcp.yo
===================================================================
RCS file: /cvsroot/zsh/zsh/Doc/Zsh/mod_tcp.yo,v
retrieving revision 1.1
diff -u -r1.1 mod_tcp.yo
--- Doc/Zsh/mod_tcp.yo	10 Sep 2001 21:33:16 -0000	1.1
+++ Doc/Zsh/mod_tcp.yo	21 May 2002 11:51:55 -0000
@@ -95,3 +95,35 @@
 In order to elicit more verbose output, use tt(-v).
 )
 enditem()
+
+subsect(Example)
+cindex(TCP, example)
+Here is how to create a TCP connection between two instances of zsh.  We
+need to pick an unassigned port; here we use the randomly chosen 5123.
+
+On tt(host1),
+example(zmodload zsh/net/tcp
+ztcp -l 5123
+listenfd=$REPLY
+ztcp -a $listenfd
+fd=$REPLY)
+The second from last command blocks until there is an incoming connection.
+
+Now create a connection from tt(host2) (which may, of course, be the same
+machine):
+example(zmodload zsh/net/tcp
+ztcp host1 5123
+fd=$REPLY)
+
+Now on each host, tt($fd) contains a file descriptor for talking to the
+other.  For example, on tt(host1):
+example(print This is a message >&$fd)
+and on tt(host2):
+example(read -r line <&$fd; print -r - $line)
+prints `tt(This is a message)'.
+
+To tidy up, on tt(host1):
+example(ztcp -c $listenfd
+ztcp -c $fd)
+and on tt(host2)
+example(ztcp -c $fd)

-- 
Peter Stephenson <pws@xxxxxxx>                  Software Engineer
CSR Ltd., Science Park, Milton Road,
Cambridge, CB4 0WH, UK                          Tel: +44 (0)1223 392070


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