#!/bin/sh

PROGRAM=setup-hostname
PREFIX=

. $PREFIX/lib/libalpine.sh

# http://en.wikipedia.org/wiki/Hostname#Restrictions_on_valid_host_names
valid_hostname() {
	# check length
	if [ $(echo "$1" | wc -c) -gt 63 ]; then
		echo "Hostname '$1' is too long."
		return 1
	fi
	# check that it only contains valid chars
	if ! [ -z "$(echo $1 | sed 's/[0-9a-z-]//g')" ]; then
		echo "Hostname must only contain letters (a-z), digits (0-9) or -"
		return 1
	fi
	# must not start with -
	case "$1" in
		-*) echo "Hostname must not start with a '-'"; return 1;;
	esac
	return 0
}

while true; do
	HOST=`hostname`
	echon "Enter system hostname (short form, e.g. 'foo') [$HOST]: "
	default_read HOST `hostname`
	if valid_hostname "$HOST"; then
		break
	fi
done

mkdir -p "$ROOT/etc"
echo "$HOST" > "$ROOT/etc/hostname"