Re: Printing specific line numbers

you can use Tie::File and treat the file as an array, and take an array slice:

use Tie::File;
use Fcntl 'O_RDONLY';
my @array;
my $filename = '/etc/passwd';
tie @array, 'Tie::File', $filename, mode=>O_RDONLY or die;

open NUMS, "line_num_file" or die;
my @line_nums = map { s/\s+$//s; $_ } <NUMS>;
close NUMS;

my @lines = @array[ @line_numes ];
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Re^2: Printing specific line numbers by sgifford (Prior) on Jun 01, 2006 at 22:00 UTC
And as requested, here's a command-line version of that: `perl -MTie::File -ne 'BEGIN{tie(@f,"Tie::File",shift,mode=>0,autochomp +=>0) or die "tie failed $!"} print@f[$_..$_+2]'` [download] Give the filename to read first, and any other filenames given will contain line numbers; if only one filename is given, numbers come from `STDIN`. For example: `$ echo 0 \|perl -MTie::File -ne 'BEGIN{tie(@f,"Tie::File",shift,mode=>0 +,autochomp=>0) or die "tie failed $!"} print@f[$_..$_+2]' /etc/passwd root:x:0:0:root:/root:/bin/bash bin:x:1:1:bin:/bin:/sbin/nologin daemon:x:2:2:daemon:/sbin:/sbin/nologin $` [download] -- sgifford's Web page	[reply] [d/l] [select]

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Re^2: Printing specific line numbers
by sgifford (Prior) on Jun 01, 2006 at 22:00 UTC

perl -MTie::File -ne 'BEGIN{tie(@f,"Tie::File",shift,mode=>0,autochomp
+=>0) or die "tie failed $!"} print@f[$_..$_+2]'
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Give the filename to read first, and any other filenames given will contain line numbers; if only one filename is given, numbers come from STDIN. For example:

$ echo 0 |perl -MTie::File -ne 'BEGIN{tie(@f,"Tie::File",shift,mode=>0
+,autochomp=>0) or die "tie failed $!"} print@f[$_..$_+2]' /etc/passwd
root:x:0:0:root:/root:/bin/bash
bin:x:1:1:bin:/bin:/sbin/nologin
daemon:x:2:2:daemon:/sbin:/sbin/nologin
$
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