in reply to emulate "fgrep -f file" with results ordered by "file"

but this does not work...
That is not descriptive enough, and you haven't shown enough of your code, but here are a couple suggestions:

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Re^2: emulate "fgrep -f file" with results ordered by "file"
by coldy (Scribe) on Mar 15, 2011 at 02:32 UTC
    thanks for the suggestion - chmop worked. There is one other problem - it is fairly slow. There are about 1M itmes to grep from @list and @large has a few more lines than that (about 1.2M )..any ideas on how to do this more efficiently?
[reply]

      You could create an index (=hash lookup table) by the first field of 'large'.  Then loop over @list and check if the key exists in the lookup table.

      Something like 

      my %index;
while (<DATA>) {   # your $large
    my ($f1) = split;
    $index{$f1} .= $_;
}

my @list = qw(foo r2c1 bar r3c1);
for (@list) {
    print $index{$_} if exists $index{$_};
}

__DATA__
r1c1 r1c2 r1c3
r2c1 r2c2 r2c3
r3c1 r3c2 r3c3

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[d/l]
        thankyou very fast indeed!
[reply]

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