Switch to root when started as regular user

In collaborative builder machine, these scripts are often allowed to become root
via sudo. This patch avoid to prefix them by sudo each time or call su.

Signed-off-by: Pierre Schmitz <pierre@archlinux.de>

arch-nspawn.in

@@ -37,8 +37,8 @@ while getopts 'hC:M:c:' arg; do
 done
 shift $(($OPTIND - 1))
 
-(( $EUID != 0 )) && die 'This script must be run as root.'
 (( $# < 1 )) && die 'You must specify a directory.'
+check_root "$0" "$@"
 
 working_dir=$(readlink -f "$1")
 shift 1

archbuild.in

@@ -40,9 +40,7 @@ done
 # Pass all arguments after -- right to makepkg
 makechrootpkg_args+=("${@:$OPTIND}")
 
-if (( EUID )); then
-	die 'This script must be run as root.'
-fi
+check_root "$0" "$@"
 
 if ${clean_first} || [[ ! -d "${chroots}/${repo}-${arch}" ]]; then
 	msg "Creating chroot for [${repo}] (${arch})..."

lib/common.sh

@@ -228,3 +228,16 @@ find_cached_package() {
 			return 1
 	esac
 }
+
+##
+#  usage : check_root ("$0" "$@")
+##
+check_root() {
+	(( EUID == 0 )) && return
+	if type -P sudo >/dev/null; then
+		exec sudo -- "$@"
+	else
+		exec su root -c "$(printf '%q' "$@")"
+	fi
+	die 'This script must be run as root.'
+}

makechrootpkg.in

@@ -81,7 +81,7 @@ while getopts 'hcur:I:l:nTD:d:' arg; do
 	esac
 done
 
-(( EUID != 0 )) && die 'This script must be run as root.'
+check_root "$0" "$@"
 
 [[ ! -f PKGBUILD && -z "${install_pkgs[*]}" ]] && die 'This must be run in a directory containing a PKGBUILD.'
 

mkarchroot.in

@@ -35,9 +35,10 @@ while getopts 'hC:M:c:' arg; do
 done
 shift $(($OPTIND - 1))
 
-(( $EUID != 0 )) && die 'This script must be run as root.'
 (( $# < 2 )) && die 'You must specify a directory and one or more packages.'
 
+check_root "$0" "$@"
+
 working_dir="$(readlink -f $1)"
 shift 1