section

#! /bin/sh

# section - print line matching regexp with following indented section
#
# Copyright (C) 2018-2021 by Erik Auerswald <auerswal@unix-ag.uni-kl.de>
#
# Copying and distribution of this file, with or without modification,
# are permitted in any medium without royalty provided the copyright
# notice and this notice are preserved.  This file is offered as-is,
# without any warranty.

test -z "$1" && { echo 'Usage: section PATTERN [FILE...]'; exit 1; }
PATTERN="$(printf -- '%s' "$1" | sed 's/\\/&&/g')"
shift
exec /usr/bin/awk -v pattern="$PATTERN" -- '
function update_state(pat_match, loc_ind) {
	if (match($0, /^[ \t]+/)) {
		loc_ind = substr($0, RSTART, RLENGTH)
		gsub(/\t/, "        ", loc_ind)
	}
	loc_ind_len = length(loc_ind)
	if (pat_match || (in_section && (loc_ind_len > ind_len))) {
		if (!in_section || (loc_ind_len <= ind_len)) {
			ind_len = loc_ind_len
		}
		in_section = 1
		print $0
	} else {
		in_section = 0
		ind_len = 0
	}
}
$0 ~ pattern { update_state(1) }
$0 !~ pattern { update_state(0) }
' "$@"