You might want to try:
print join("\n",grep {/$a/i} @lines);
to print any lines containing $a.
And change
@lines=$a   # this should be an error if you use warnings.
to 
@lines=<INFO>;
close INFO;

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Originally posted as a Categorized Answer.

In reply to Re: How to do pattern matching and output the results? by repson
in thread How to do pattern matching and output the results? by Anonymous Monk

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