Re: Regex question

Keep an array of the last lines read:

#!/usr/bin/perl
use Getopt::Std;
my %o;
getopt 'b:a:',\%o;
my $pat = shift;
my @last; 
while(<>) {
    if (/$pat/) {
        @last = ();
        <> for 1..$o{a};
        next;
    }   
    push @last, $_;
    print shift @last if $o{b} < @last;
}
print @last;
[download]

Comment on Re: Regex question Download Code

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Re^2: Regex question by ikegami (Patriarch) on Jan 26, 2009 at 13:15 UTC
That will fail if you have two matches within "A" lines of each other `01 keep 02 discard B5 03 discard B4 04 discard B3 05 discard B2 06 discard B1 07 somepat 08 discard A1 09 somepat 10 discard A1 11 discard A2 <- Not dicarded 12 discard A3 <- Not dicarded 13 keep` [download]	[reply] [d/l]
Re^3: Regex question by shmem (Chancellor) on Jan 26, 2009 at 14:34 UTC
Okaay... that will do: `#!/usr/bin/perl use Getopt::Std; my %o; getopt 'b:a:',\%o; my $pat = shift; my @last; OUTER: while(<>) { if (/$pat/) { @last = (); for my $i(1..$o{a}) { $_ = <>; redo OUTER if /$pat/; } next; } push @last, $_; print shift @last if $o{b} < @last; } print @last;` [download]	[reply] [d/l]