TCL/Expect

Expect is a Tcl scripting language extension. Expect is often used for automation of interactive telecom applications. It is also widespread in the Telecom/Network testing. A lot of Telecom/Network test equipment (Spirent, IXIA, Agilent, JDSU) manufactures support TCL/Expect as test automation scripting language.

Using TCL/Expect you can easily automate some actions need to be executed many times during long period of time:

1.  The script below connects to Linux Host with IP-address 192.168.10.10 and executes Linux commands "ifconfig eth1 down" and "ifconfig eth1 up" 99 times with 1 second delay between the commands:

# Set Timeout to wait response from Host 

set timeout 30;

# Configuration parameters

set cfgHost            "192.168.10.10"
set User        "root"
set Password    "admin123"

# Log in Linux Host

spawn ssh -l root $cfgHost
expect "login as:" { send "$User\r" }
expect "*assword:" { send "$Password\r" }
sleep 1;

#  Disable/Enable Linux interface in cycle

for { set i 1 } { $i <  100 } { incr i } {
 sleep 1;
 expect "*~#" { send "ifconfig eth1 down\r" }

 expect "*~#" { send "ifconfig eth1 up\r" }
}


expect eof;
exit;

2.  The script below connects to Cisco router and executes "sh interfaces status" command, all the Cisco console output will be sent to the predefined log file:

# Connect  Cisco router

spawn telent 10.10.10.10
expect "*ogin:" { send "admin" }
expect "*assword:" { send "123456\r" }

# Open a logfile for the script output

log_file -noappend fulloutput.log;
expect "*#" {send "sh interfaces status\r"}

# Finish script logging:

log_file

exit;