#!/usr/bin/perl -w
#!C:/xampp/perl/bin/perl -w
#
#    This file is part of a perl tutorial
#
#    (C) Copyright 1999 Hans Kern
#
#    File name    : pldemo10.cgi
#    Created by   : Hans Kern
#    Creation date: 25.5.99
#

#    Beispiel für eval.

print "Content-type:text/plain\n\n";

my( $x, $y);
my %Parameter       = (
   "x" => 5,
   "y" => 10
  );

# eval mit string
# Vertauschung von " und ' nicht möglich!!
$Missing  = "";
foreach $name ( keys( %Parameter ) ) {
   print "$name $Parameter{$name}\n";
   eval "\$$name = \$Parameter{$name};
         \$Missing  .= ',$Parameter{$name}';
   ";                                           
}                                                
print "***$Missing***\n";
print "$x\n";
print "$y\n";

# eval mit Block, klappt nicht.
#$x = 15;
#$y = 20;
#$Missing  = "";
#foreach $name ( keys( %Parameter ) ) {
#   print "$name $Parameter{$name}\n";
#   eval {\$$name = \$Parameter{$name};
#         \$Missing  .= ',$Parameter{$name}';
#   };                                           
#}                                                
#print "***$Missing***\n";
#print "$x\n";
#print "$y\n";

# eval klappt nicht.
#$x = 25;
#$y = 30;
#$Missing  = "";
#eval "foreach \$$name ( keys( %Parameter ) ) {
#         \$Missing  .= ',$Parameter{$name}';
#      }                                                
#";                                           
#print "***$Missing***\n";
#print "$x\n";
#print "$y\n";