perl -lnE "BEGIN{$r=shift;$r=qr/$r/;$n=shift@ARGV;push @ARGV,$ARGV[0]}eof&&!$y?$y=close ARGV:/$r/&&!$y?push @u,$.-$n..$.+$n:$y&&!($.~~@u)?say:0" XXXXX 1 next-and-previous.txt
11111
22222
33333
44444

perl -lnE "BEGIN{$r=shift;$r=qr/$r/;$n=shift;push @ARGV,$ARGV[0]}eof&&!$y?$y=close ARGV:/$r/&&!$y?push @u,$.-$n..$.+$n:$y&&!($.~~@u)?say:0" XXXXX 2 next-and-previous.txt
22222