Something like this?

@arr = map {qr/\Q$_\E/} @arr;
my @keepers = do {
    local $" = '|';
    grep { m/@arr/ } <>;
};
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If that's too slow, you can make a hash with @arr as keys and look for existence over a split of your input lines.

my (%hsh, @keepers);
@hsh{@arr} = ();
while (<>) {
    push @keepers, $_ if grep {exists $hsh{$_}} split;
}
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Reading the file line by line is not a big drag on speed if you get to only read the file once.

That's a very cool way of solving this problem, I learned quite a bit from reading it. I noticed that this returns lines that contain at least one element in @arr. I made a simple modification to the second algorithm to only return lines that have all elements in @arr. The OP didn't specify if he meant one or all array elements, so here's my modification for brevity's sake.

my (%hsh, @keepers);
@hsh{@arr} = ();

while (<>) {
    push @keepers, $_ unless grep {!exists $hsh{$_}} split;
}
[download]

Thanks for enlightening me with that code sample Zaxo

Zaxo,
I wonder what riz meant by "both @arr & file are big"? I know that demerphq has provided patches to bleed perl for alternation in regexen, but this can get slow quickly in 5.8.x. Ok - let's assume that for some reason a hash isn't an option (order is important) and memory consumption is at a premium already. Is there a way to make it any faster?

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I have no idea how well this scales but my guess is it is a failed attempt. I doubt the reciprocal of this solution (indexing file offsets instead) would have been any better. It was a fun experiment anyway.

Cheers - L~R

Hello all,
Thank to all. I found out that there is a perl module member.pm available which should perform the same function as Skill language member().
Again I am stuck in the loop. I want to print the pair of integer values for only the member of @arr e.g. in this case the pair integer values for Stack3 and Stack5 should be printed. Somehow the member function is reading only the first element of my array.Somebody advice where I am doing wrong?

Here is my code;

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And here is the file;
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20050627 Edit by ysth: code tags

 
open (FH,"filename here") or die;

while ( my $line = <FH> ) {
   if ( $youhash->{$line} ) { 
   #he, a match! 
   }
}
[download]

You'll have to explain what you want to do a bit better, I'm afraid. Most of us are not proficient in SKILL (at least I'm not -- I had not heard of it before your post :) ), and it's not quite clear what you want to do from the rest of your post. Could you clarify a bit?