in reply to qr// and user provided regex patterns...
ikegami provided a solution to your direct question.
An alternate approach that I usually employ is to provide another command-line option for a case-sensitive match.
my $pattern = ($options{i}) ? qr/$options{c}/i : qr/$options{c}/;
The following does a case-sensitive match:
regexTester -c 'Bill Clinton'
The following does a case-insensitive match:
regexTester -i -c 'Bill Clinton'
See Finding commands in Unix PATH for a complete example with POD instructions.
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