Let me quote from the Camel, second edition, dating from 1996, shortly after the release of perl 5.003. On page 54, while discussing the angle operator:
Here's how it works: the first time <> is evaluated, the @ARGV array is checked, and if it is null, $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
    }

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is equivalent to the following Perl-like pseudocode: 
    @ARGV = ('-') unless @ARGV;
    while ($ARGV = shift) {
        open(ARGV, $ARGV) or warn "Can't open $ARGV: $!\n";
        while (<ARGV>) {
            ...          # code for each line
        }
    }

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except that it isn't so cumbersome to say, and will actually work. It really does shift @ARGV and put the current filename into variable $ARGV. It also uses filehandle ARGV internally -- <> is just a synonym for <ARGV>, which is magical. (The pseudocode doesn't work because it treats <ARGV> as non-magical.)
If you then switch to pages 191-194, it discusses the open function, including the effects of leading and trailing pipes in the filenames.

In reply to Re^5: magic-diamond <> behavior -- WHAT?! (docs) by JavaFan
in thread magic-diamond <> behavior -- WHAT?! by repellent

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