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]'
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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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