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in reply to Re: <> oddity ?
in thread <> oddity ?

If you call the code below stdin.pl, 

while(<>) {
    print;
}

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then all three commands below result in the same output: 

$ perl stdin.pl stdin.pl
$ perl stdin.pl < stdin.pl
$ cat stdin.pl | perl stdin.pl

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Replies are listed 'Best First'.
Re^3: <> oddity ?
by LanX (Saint) on Mar 27, 2013 at 10:48 UTC
    you're right

    from perlop

           The null filehandle <> is special: it can be used to emulate the
       behavior of sed and awk.  Input from <> comes either from standard
       input, or from each file listed on the command line.  Here’s how it
       works: the first time <> is evaluated, the @ARGV array is checked, and
       if it is empty, $ARGV[0] is set to "-", which when opened gives you
       standard input.  The @ARGV array is then processed as a list of
       filenames.  The loop
    

           while (<>) {
               ...                     # code for each line
           }
    

       is equivalent to the following Perl-like pseudo code:
    

           unshift(@ARGV, '-') unless @ARGV;
           while ($ARGV = shift) {
               open(ARGV, $ARGV);
               while (<ARGV>) {
                   ...         # code for each line
               }
           }

    Cheers Rolf

    ( addicted to the Perl Programming Language)

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