fig19_05.pl

PERL语言资料 可以用于PERL程序设计

#!perl -T
# Figure 19.5: fig19_05.pl
# Using taint mode.

use warnings;
use strict;
use CGI qw( :standard );

print( header(), start_html( "Prevent improper input" ) );

my $cgi = new CGI();

unless ( $cgi->param() ) {
   print( "Type some text, then press Enter",
          " and I will display it for you." );
   my $form = new CGI();
   print( $form->startform(),
          $form->textfield( 'words', '', 20 ),
          $form->endform() );
}
else {
   my $words = $cgi->param( 'words' );
   print( "You entered: $words.", br() );

   if ( $words =~ /^(\w*)$/ ) {
      print( "Attempting to execute: $1.", br() );
      my @matches = `$1`;  
      
      if ( @matches ) {
         print( br(), join( br(), @matches ) );
      }
      else {
         print( "'$words' was not a shell command.", br() ); 
      }
   }
   else {
      print( "Invalid input. Re-enter without any symbols." );
   }
}

print( end_html() );


###########################################################################
#  (C) Copyright 2001 by Deitel & Associates, Inc. and Prentice Hall.     #
#  All Rights Reserved.                                                   #
#                                                                         #
#  DISCLAIMER: The authors and publisher of this book have used their     #
#  best efforts in preparing the book. These efforts include the          #
#  development, research, and testing of the theories and programs        #
#  to determine their effectiveness. The authors and publisher make       #
#  no warranty of any kind, expressed or implied, with regard to these    #
#  programs or to the documentation contained in these books. The authors #
#  and publisher shall not be liable in any event for incidental or       #
#  consequential damages in connection with, or arising out of, the       #
#  furnishing, performance, or use of these programs.                     #
###########################################################################