In the Perl script "test.pl":        ...		        my $WEBROOT = <WEBROOT_PATH>;        ...To force variable substitution try:        $export WEBROOT_PATH=/usr/local/webroot        $sed 's/<WEBROOT_PATH>/$WEBROOT_PATH/' < test.pl > outBut this just gives:        my $WEBROOT = $WEBROOT_PATH;However:        $export WEBROOT_PATH=/usr/local/webroot        $eval sed 's%\<WEBROOT_PATH\>%$WEBROOT_PATH%' < test.pl > out#        ====That works fine, and gives the expected substitution:        my $WEBROOT = /usr/local/webroot;### Correction applied to original example by Paulo Marcel Coelho Aragao.