如何使用Perl打开文件的当前行号？

Question

open my $fp, '<', $file or die $!;

while (<$fp>) {
    my $line = $_;
    if ($line =~ /$regex/) {
        # How do I find out which line number this match happened at?
    }
}

close $fp;

Answer 1

使用$.(见perldoc perlvar).

Answer 2

您也可以通过OO界面完成:

use IO::Handle;
# later on ...
my $n = $fp->input_line_number();

这也是perldoc perlvar.