I'm not sure from your question what exactly you're trying to accomplish. Here are a couple of options...

  1. Determine if the value in $CD is valid 
    my $valid_chars = 'CETLMNPA';
if ($CD =~ m/^[$valid_chars](?:,[$valid_chars])*$/) {
   print "Valid!"
}
else {
   die "Invalid!"
}

    [download]

    Let's break down that regular expression: 

    m/
   ^[$valid_chars]   #the string must start with one of the valid char
+s
   (?:               #start group, but don't capture!
      ,              #could have a comma
      [$valid_chars] #and another valid char
   )*                #and that comma+valid char could repeat 0 or more
+ times
   $                 #until the end of the string
/x                   #this is here to allow me to use all these commen
+ts

    [download]
  2. Use as configuration values

    For example, if I want to know at various points in code if a given flag is set: 

    my %config = map { $_ => 1 } split(',', $CD);
## later on...
if ( $config{L} ) { print "L was set!" }

    [download]

    You might use the validation from above in combination with this.

<–radiant.matrix–>
Ramblings and references
The Code that can be seen is not the true Code
I haven't found a problem yet that can't be solved by a well-placed trebuchet

In reply to Re: Regular expression for combination of data by radiantmatrix
in thread Regular expression for combination of data by isha

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