# @_ is a list of variable name
# if @_ contains "i" and "j" and $i == 42 $j eq "freeBSD",
# the function should print :
# i : 42
# j : freeBSD
sub display_init {
        my @variables = @_;
        my $value;

        foreach (@variables) {
                eval("\$value=\$$_");
                if (! defined($value) ) { $value = "undefined"; }
                print "$_ : $value\n";
        }
}