hello all,

i'm having some reliability problem with expect, what i'm trying to do is basically go to all the computers on the network and do an update to all of them. so i have two codes;

1-bash script --> get all ip address , for each run expect command
2- expect script to do the update

the problem i'm having is for about 90 % of the ip addresses the expect works fine however for the rest for some reason it doesn't, the password that i supply will just pop up and it would not take it.

i really hope that i make sense, let me know if you need any other info,

the code is below:

thanks in advance.


//bash script

LIST=`ifconfig | awk '/P-t-P/ {print $3}' | cut -c 7-20 | sort`
for ip in $LIST
do
echo $ip >> check.txt
./update2 $1 $ip $2 >> check.txt
sleep 1
done
exit

//expect program "update2"

set password [lindex $argv 2]
set ip [lindex $argv 1]
spawn /usr/bin/scp or ssh " basically do the update"
sleep 1
expect "password:"
send "$password\r"
expect eof

Try removing the "sleep 1" in update2. It's possible that the
password prompt is being sent before the expect "password:" line
is executed.

Put exp_internal 1 as the first line in your program. Without it, you'll never be able to figure out what your spawned program sends to you and how the output is being interpreted by Expect.

Expect is reliable, I have some Expect scripts running in a process controller and they spawn telnet and snmp programs. Some of them once every second, 24/7 for months already.

So I think you didn't mean to ask if Expect is reliable, but rather what unexpected (no pun intended) could be happening.

jlinkels

Thanks guys,

Actually i kind of figured it out, as usual i kind of rushed into conclusions without doing what i'm supposed to do (more debuggin) , it seems that i have to sleep more than 1 sec, because in my setup the network connection for each location (IPs) differs from one another. for example if the network connection is bad, it will take more time to ssh --> need more time to expect a password. i increased the sleep to 4 seconds and it worked.

Thanks again guys , appreciate your help

Expect knows how to handle timeouts. Check the timeout statement.

jlinkels