I think I made some progress:


     $search = $top->Entry ('-width'            => 20,
                            '-validate'         => 'key',
                            '-validatecommand'  => sub {$_[1] =~/\w+/ 
+;} ,
                            '-invalidcommand'   => sub {$top -> bell()
+ ;},
               ) ->pack('-side' => 'left');

[download]

I found the code on 'Mastering Perl/Tk' -- I modified it to work with my program. But I still need it to accept ':' and '-'. As for invalid input it should do something like this: 

'-invalidcommand' => sub {$_[1] =~/^[[:cntrl:]] ;
                          $top -> bell;
                         }

[download]
But it sill locks up...

2021-03-09 Athanasius added code tags around final snippet.

In reply to Re^2: Stopping bad input (harder than sanitizing) by Anonymous Monk
in thread Stopping bad input (harder than sanitizing) by Anonymous Monk

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