Expect 在网络管理中发挥着重要作用

...
} "-rlogin" {
set login "rlogin"
continue
} "-slogin" {
set login "slogin"
continue
} "-ssh" {
set login "ssh"
continue
} "-telnet" {
set login "telnet"
continue
...

telnet $MY_ROUTER
[User: admin]
[password: ...]
CCNA01#show running-config
[... Current configuration:
... version 12.0 ...
FIFTY LINES MORE OF CONFIGURATION DETAIL
...
End]

#!/usr/bin/expect
# initialize host, password, ...
package require Expect
set prompt {[00m# }
spawn telnet $host
expect {User: }
send admin\r
expect password:
send $password\r
expect -exact $prompt
send "show running-config\r"
expect -exact $prompt
send exit\r

#!/home/claird/local/ActiveTcl/bin/tclsh
package require Expect
log_user 0
# Initialize user, passphrase, ... here.
# Sequentially login and issue time-consuming commands to all
# hosts.
for {set i 0; set delay 8} {$delay > 0} {incr i; incr delay -1} {
spawn ssh $user@$host
set sid($i) $spawn_id
expect rsa':
send $passphrase
expect "Last login"
expect -ex $prompt
set active($sid($i)) $i
send -i $sid($i) "echo `date`; sleep $delay; echo `date`; echo \
'$delay done on $i.'\r"
}
while {[llength [array names active]]} {
expect -i [array names active] -ex $prompt {
puts "RECEIVED:  $::expect_out(buffer)"
send -i $expect_out(spawn_id) exit\r
expect -i $expect_out(spawn_id) eof
unset active($expect_out(spawn_id))
}
}

RECEIVED:  echo `date`; sleep 1; echo `date`; echo '1 done on 7.'
Mon Apr 23 22:15:15 UTC 2007
Mon Apr 23 22:15:16 UTC 2007
1 done on 7.
RECEIVED:  echo `date`; sleep 2; echo `date`; echo '2 done on 6.'
Mon Apr 23 22:15:15 UTC 2007
Mon Apr 23 22:15:17 UTC 2007
2 done on 6.
RECEIVED:  echo `date`; sleep 3; echo `date`; echo '3 done on 5.'
Mon Apr 23 22:15:15 UTC 2007
Mon Apr 23 22:15:18 UTC 2007
3 done on 5.
...
RECEIVED:  echo `date`; sleep 8; echo `date`; echo '8 done on 0.'
Mon Apr 23 22:15:14 UTC 2007
Mon Apr 23 22:15:22 UTC 2007
8 done on 0.