Examples:

   Make a finger service:
   
      plis 79 -ioe in.fingerd
      
      (socket connected to in.fingerd's stdin, stdout and stderr.)
      
   Make a server giving your signature at port 5555:
      
      plis 5555 -o 'cat signature' </dev/null 2>/dev/null
      
      (stdout connected to socket,
       stdin & stderr redirected to /dev/null)
      
   Make a test client for tcp connections
   (recommended instead of using telnet):
   
      pcon -f localhost 11111 -i cat -o cat
   
      (two cats: first redirects socket to stdout,
       and second redirects stdin to socket.)
   
   Make a linebuffered test client for tcp connections:
   
      pcon www.icon.fi 80 -i cat -o cat
      
   Make an echo server:
   
      plis 11111 -io cat
      
      (the cat redirects socket to socket.)
      
   Make a redirection server (this redirects all
   incoming connections in port 1234 to remotehost
   port 4123 (useful for proxying)):
   
      plis 1234 -io 'pcon remotehost 4123 -i cat -o cat'
      
      (the first cat is from pcon to plis,
       and the second is from plis to pcon.)
   
   Connect to an irc server and assign a bot to talk with
   it (stdin, stdout), errors logged:
   
      pcon ircserver.org 6667 -io './irc-bot' 2>errors.log

   Redirect world (10.10.10.10) smtp (25) port to virus checker (192.0.0.2),
   redirect intra (192.0.0.1)   smtp (25) port to some other port (900):

      plis -h10.10.10.10 25 -io 'pcon 192.0.0.2 25 -i cat -o cat' 2>/dev/null &
      plis -h192.0.0.1 25 -io 'pcon 127.0.0.1 900 -i cat -o cat' 2>/dev/null &
