I don't see why -i is required. If it's not on the command line, then it must be on STDIN, so there's no reason to use -i. 

my $input = @ARGV ? shift(@ARGV) : <STDIN>;

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That's the approach <ARGV> uses.

In reply to Re^2: How to write a program to read stdin or command line? by ikegami
in thread How to write a program to read stdin or command line? by princepawn

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