I'm trying to read regular expressions from a parameter file. This works as long as I specify the outer delimiters around the variable in the code. I include the delimiters in the variable, otherwise I have no way of allowing users to generate expressions that use external modifiers like: 
    /coWs/i

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The parameter file (following) uses the first character to specify what operation (search or exception) the user wants to perform. The regexp runs from column 2 to the end of the line. What I want to do is use delimiters and modifiers included in the parameter file: 
    +/six/i
    -/were/

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This works when delimiters are not included in the parameter file, but is very limited and flakey. 
    +[Ss][Ii][Xx]

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Here is some of the code: 

# Process Global Exceptions first

foreach $except (@$glob_except) {
    $cexcept = substr($except, 1);
    $targf{$tkey} = "1:0" if ($tkey =~ /$cexcept/);  # EXPANDS VARIABL
+E HERE

### I would like the delimeters to be contained in the variable:  ...(
+$tkey =~ $cexcept);

}

elsif ($ttype eq '+') {
    if ($tkey =~ /$ttext/) { ;  # EXPANDS VARIABLE HERE
        $targf{$tkey} = "3:$err_rtn";
        $found = 1;
    }
}
elsif ($ttype eq '-' && substr($targf{$tkey},0,1) == 3) {
    if ($tkey =~ /$ttext/) {;  # EXPANDS VARIABLE HERE
        $targf{$tkey} = "2:0";
        $found = 0;
    }
}
else {
### ETCETERA     

### THIS IS HOW THE HASH CONTAINING THE MATCH STRING IS LOADED

elsif ($line_header eq '!') { ## Optional
# Spec a global exception that affects all lines
# interpolation takes place. 
unless ($trans_state == 2) 
    {die "ERR: Global exception out of sequence";}
    push (@$glob_except, $line);    #  <= LOADING THE VARIABLE FROM
+ FILE
    # Trans state stays at 2 until set to 3 in subsequent logic

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In reply to How do pack a regular expression in a variable? by pppaulll

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