FAQ 5.3 How do I count the number of lines in a file?

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5.3: How do I count the number of lines in a file?

    (contributed by brian d foy)

    Conceptually, the easiest way to count the lines in a file is to simply
    read them and count them:

            my $count = 0;
            while( <$fh> ) { $count++; }

    You don't really have to count them yourself, though, since Perl already
    does that with the $. variable, which is the current line number from
    the last filehandle read:

            1 while( <$fh> );
            my $count = $.;

    If you want to use $., you can reduce it to a simple one-liner, like one
    of these:

            % perl -lne '} print $.; {'    file

            % perl -lne 'END { print $. }' file

    Those can be rather inefficient though. If they aren't fast enough for
    you, you might just read chunks of data and count the number of

            my $lines = 0;
            open my($fh), '<:raw', $filename or die "Can't open $filename: $!";
            while( sysread $fh, $buffer, 4096 ) {
                    $lines += ( $buffer =~ tr/\n// );
            close FILE;

    However, that doesn't work if the line ending isn't a newline. You might
    change that "tr///" to a "s///" so you can count the number of times the
    input record separator, $/, shows up:

            my $lines = 0;
            open my($fh), '<:raw', $filename or die "Can't open $filename: $!";
            while( sysread $fh, $buffer, 4096 ) {
                    $lines += ( $buffer =~ s|$/||g; );
            close FILE;

    If you don't mind shelling out, the "wc" command is usually the fastest,
    even with the extra interprocess overhead. Ensure that you have an
    untainted filename though:

            #!perl -T

            $ENV = undef;

            my $lines;
            if( $filename =~ /^([0-9a-z_.]+)\z/ ) {
                    $lines = `/usr/bin/wc -l $1`
                    chomp $lines;


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