# $NetBSD: plist-functions.awk,v 1.4 2020/09/12 06:55:08 rillig Exp $
#
# Copyright (c) 2006 The NetBSD Foundation, Inc.
# All rights reserved.
#
# This code is derived from software contributed to The NetBSD Foundation
# by Johnny C. Lam.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
# ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.

###
### join(array, start, end, separator) concatenates an array of strings
### with a separator and returns the concatenated string.  It is the
### inverse of the built-in split() function.
###
function join(array, start, end, separator,	result, i) {
	result = array[start]
	for (i = start + 1; i <= end; i++)
		result = result separator array[i]
	return result
}

###
### print_entry(entry) prints the entry to standard output.  If avoids
### printing out duplicate entries by caching ones that have previously
### been printed.
###
function print_entry(entry) {
	if (entries[entry] == "") {
		entries[entry] = entry
		print entry
	}
}

function getenv_or_die(varname) {
	if (varname in ENVIRON)
		return ENVIRON[varname]
	print "ERROR: "varname" must be defined." | "cat 1>&2"
	exit(1)
}