in reply to Re: Question on Reading a file inside while and counting no.of lines
in thread Question on Reading a file inside while and counting no.of lines

It starts at zero…

Actually, it starts at 1, not 0.

C:\strawberry>perl -nE "say $." README.txt | head
1
2
3
4
5
6
7
8
9
10

C:\strawberry>

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It's probably also worth demonstrating here the usual idiom for resetting the line number to 1 for each file in @ARGV when using <>.

# @ARGV may have more than one file in it

while (<ARGV>) {
    print "$.:$_\n";
}
continue {
    close ARGV if eof;
}

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Re^3: Question on Reading a file inside while and counting no.of lines
by davido (Cardinal) on Jun 16, 2013 at 06:50 UTC

    *head-bonk*

    Ever since the alien abduction I've had a hard time remembering that $. is 1-based. ;)


    Dave

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Re^3: Question on Reading a file inside while and counting no.of lines
by AnomalousMonk (Archbishop) on Jun 16, 2013 at 22:33 UTC
    It starts at zero...

    Quoth perlvar (emphases added): Each filehandle in Perl counts the number of lines that have been read from it. ... When a line is read from a filehandle (via "readline()" or "<>") ... $. becomes an alias to the line counter for that filehandle.

    So I would say davido's assertion is not without justification:  $. starts out undefined (which is very like zero) and happily becomes 1 by aliasing when the first line is read. I assume the internal filehandle line counter is 0 or undefined prior to any read on the handle. So there. 

    >perl -wMstrict -le
"my $filename = 'text';
 open my $fh, '<', $filename or die qq{opening '$filename': $!};
 ;;
 print qq{\$. initially: }, defined $. ? qq{'$.'} : 'undefined';
 ;;
 while (<$fh>) {
   chomp;
   print qq{$.: '$_'};
   }
 ;;
 close $fh or die qq{closing '$filename': $!};
"
$. initially: undefined
1: 'now is the time'
2: 'foo bar baz'
3: 'how now brown cow'
4: 'four score and seven'

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