Re: search for blank lines by RegEx

My naiive approach (I'm a newbie) would be to check two lines in a row, something like...

my $prev;
while (<DATA>) {
    if (/^\s*$/ && $prev =~ /^\s*$/) {
        # Two blank lines in a row found
    }
    $prev = $_;
}
[download]

It doesn't look a particularly Perl way to do it though, so I guess my inexperience is showing.

Comment on Re: search for blank lines by RegEx Download Code

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Re^2: search for blank lines by RegEx by Aragorn (Curate) on Sep 07, 2004 at 09:02 UTC
For processing a huge file, this is a lot more (memory-) efficient than trying to load the complete file into memory. So I don't think this is a bad way to do it. Arjen	[reply]
Re^3: search for blank lines by RegEx [!] by Anonymous Monk on Sep 07, 2004 at 10:47 UTC
The question asked for a regex solution. If you want to deviate and use a loop, there's no need to use a couple of regexes inside the loop. Something like (untested): `perl -lne 'die "Line ", $.-2, "\n" if ($e = length() ? 0 : $e+1) == 2'` [download]	[reply] [d/l]
Re^4: search for blank lines by RegEx [!] by robharper (Pilgrim) on Sep 07, 2004 at 15:41 UTC
Fair point about being faithful to the question -- and thanks for the alternate approach (above my head at the moment, but I'll crack out the documentation to find out...), but I do remember reading somewhere or other about asking questions in ways that don't prejudice the answers. Still, this was an interesting question for the level of experience I have in Perl.	[reply]