my %vars;

open(CONF," conf.file");
while(<CONF>) {
    ($variablecmd,$variablename,$newdata) = split(/ /, $_);
    if ($variablecmd eq "setVariable") {
        $vars{$variablename} = $newdata;
} elsif ($variablecmd eq "catVariable") {
        #assign data to varaible named $variablename
        if(exists $vars{$variablename}) {
            $vars{$variablename} = $newdata;
        } else {
             die "assignment to undeclared variable";
        }
    }
}
close(CONF);