Because your var ($p) contains a backslash follows by a square bracket (\[). $m gets interpolated in the RE, so in the first case, the \[ will be interpolated as only a square bracket, and you lose the backslash.

Paul

In reply to Re: regexp matching with "\[" in the substring to be matched by rev_1318
in thread regexp matching with "\[" in the substring to be matched by ISAI student

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