Perl shell-out to script dunna work. Works on command line. Why?

jlangelier · 08-28-2004, 12:49 AM

I've got a perl script which executes:

my $retval = `sudo /usr/bin/firewall`;

... and comes back with a bunch of errors. First is:

/sbin/ipchains: host/network `-j' not found

If I run 'sudo /usr/bin/firewall' at the bash prompt, no problem. No errors.

This is the line in my bash script which works when launched at the command prompt, but not with launched perl backticks:

/sbin/ipchains -A input -i $LOOPBACK_INTERFACE -j ACCEPT

Any help greatly appreciated.

btmiller · 08-28-2004, 03:00 AM

My guess is that somewhere there's an environment variable or four that is set when you run in an interactive shell and is not set when you run as a shell script. An obvious first candidate is this $LOOPBACK_INTERFACE -- where is this variable set? Maybe print it out to be sure it's being set correctly. You can also try having Perl exec the script in debug mode (bash --debug <script>) and go through and examine the state of things to figure out where the problem is.