Script not logging to log file. Why? - bash

Question

I have an expect/Tcl script as part of my bash script that logs into a remote router. Now, for testing purposes I am trying to handle the issue of time-out's. My problem is that the expect/Tcl script is not logging to my log file, and when it does it is logging everything the SSH connection is printing to my prompt which is not what I want.
Here's my expect script:
/usr/bin/expect<<EOF
set timeout 5
set send_human {.1 .3 1 .05 2}
set myStamp [exec date +\[%d\/%m\/%Y\ \%T\]]
set log_file ~/mylogfile.log
spawn ssh -o "StrictHostKeyChecking no" "me\#$1"
expect {
"password: " { send -h "mypassword\r" }
"No route to host" { exit 1 }
timeout { send_log "\$myStamp Timed out to $1\n"]; exit 1 }
}
send -h "reboot in 1\r"
sleep 1
send -h "exit\r"
expect eof
EOF
Please bear in mind that this is part of a function within my bash script that is passed the router name, hence the argument $1.
Any ideas?

Answer 1

You want to use the log_file command, not set a log_file variable
log_file ~/mylogfile.log
Other notes:
Tcl has a very nice builtin command to handle time, don't need to call out to date:
set myStamp [clock format [clock seconds] -format {[%d/%m/%Y %T]}]
the # character is not special in Tcl/expect and does not need to be escaped:
spawn ssh -o "StrictHostKeyChecking no" "me#$1"
As noted, log_file logs a transcript of the session. Just to log specific messages, you can use plain Tcl:
/usr/bin/expect <<EOF
proc log_msg {msg {to_stdout no}} {
set log_line "[timestamp -format {[%Y-%m-%d %T]}] \$msg"
set fh [open ~/mylogfile.log a]
puts \$fh \$log_line
close \$fh
if {\$to_stdout} {puts \$log_line}
}
# ...
expect {
"No route to host" {
log_msg "No route to host" yes
exit 1
}
timeout { log_msg "Timed out to $1"]; exit 1 }
}
# ...
EOF
This opens and closes the log for each message, which adds a bit of overhead. If milliseconds are important, open the log in the global scope, and use the global variable holding the file hendle in the log_msg proc.