[[add information about expect's spawn command, pointers to its man page on http://www.tcl.tk/man/, etc.]]


spawn creates a session with a program or remote device that Expect can manage.  Spawned sessions can be automated using other Expect commands, such as expect, interact and exp_send.

The man page for spawn is actually part of the Expect man page http://www.tcl.tk/man/expect5.31/expect.1.html.


A very simple example - ping an ip address:



        #!/bin/sh
	# The next line is executed by /bin/sh, but not tcl \
	exec /homes/ashnoc01/noc/rbacon/tcl/ActiveTcl/bin/tclsh8.4 $0 ${1+"$@"}

	package require Expect

	spawn -noecho /usr/local/bin/nping -c 5 $argv
	log_user 0
	expect {
		"\r"	{
			puts -nonewline "$expect_out(buffer)"
			exp_continue
			}
		eof	{
			puts -nonewline "$expect_out(buffer)"
			}
		}
	puts "AutoPing finished\n"
	exit

Output:

  > AutoPing 62.188.74.130
  PING 62.188.74.130: 64 data bytes
  EchoReply from 62.188.74.130: len=64 ttl=242 seq=0 time=81.157 ms.
  EchoReply from 62.188.74.130: len=64 ttl=242 seq=1 time=80.768 ms.
  EchoReply from 62.188.74.130: len=64 ttl=242 seq=2 time=80.709 ms.
  EchoReply from 62.188.74.130: len=64 ttl=242 seq=3 time=80.915 ms.
  EchoReply from 62.188.74.130: len=64 ttl=242 seq=4 time=80.940 ms.

  ----62.188.74.130 PING Statistics----
  5 transmitted, 5 received, 0.00% packet loss.
  round-trip (ms) min/avg/max = 80.709/80.898/81.157
                var/sdev/skew/kurt = 0.030/0.174/0.323/1.311
  AutoPing finished















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[Category Command]
[Category Expect]