Email Lists wrote: > Greetings > > Im am not a perl programmer yet I am trying to learn and am debugging > someone elses perl run script for use on a centos production box I have and > I came across this > > elif [ -z "${SMTP_CDB:-}" ] That's not perl, that is part of a shell script. ${SMTP_CDB:-} returns an empty string if the Variable $SMTP_CDB is not set. See "Parameter Expansion" in the manual page of bash. And "test -z $string" returns true, if $string is empty. Regards, Ralph -- Ralph Angenendt......ra at br-online.de | .."Text processing has made it possible Bayerischer Rundfunk...80300 München | ....to right-justify any idea, even one Programmbereich.Bayern 3, Jugend und | .which cannot be justified on any other Multimedia.........Tl:089.5900.16023 | ..........grounds." -- J. Finnegan, USC -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 189 bytes Desc: not available URL: <http://lists.centos.org/pipermail/centos/attachments/20060827/6a2f924e/attachment-0005.sig>