Hello. I have the following program.

#!/usr/bin/perl sub print_user_input { my $input = <STDIN>; print $input; } sub mock_user_input { local *STDIN; open STDIN, '<', \"this is fake user input\n"; print_user_input(); } mock_user_input(); __END__ $ perl ./scratch.pl this is fake user input 

I have successfully used the pattern displayed in the mock_user_input subroutine to test some user interfacing code I have. However I cannot wrap my head around how this actually works. What exactly does *STDIN mean and why does it need to be localized? Why are we passing a string reference as the third argument to open here? A detailed explanation of this code would be helpful for me. Thanks in advance.

submitted by /u/nicholas_hubbard
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