[PATCH 04/10] hal: Clean up scripts in tools

[Victor Lowther]

Add a little environment-variable checking function to hal-functions

It seems like every script duplicated this code in one way or another.
Centralizing it for ease of maintenance.
---
 tools/hal-functions |   15 +++++++++++++++
 1 files changed, 15 insertions(+), 0 deletions(-)

diff --git a/tools/hal-functions b/tools/hal-functions
index ec8db99..f37004a 100755
--- a/tools/hal-functions
+++ b/tools/hal-functions
@@ -23,6 +23,21 @@ hal_check_priv() {
     fi
 }
 
+# Check for environment variables.  Seems like every hal script does this.
+hal_check_env() {
+	# $1 = value of env var.
+	# $2 (optional) = name of env var.
+	[ -n "$1" ] && return
+        echo "org.freedesktop.Hal.Device.UnknownError" >&2
+	if [ -z "$2" ]; then
+        	echo "Missing or empty environment variable(s)." >&2
+	else
+		echo "Missing or empty environment variable $2" >&2
+	fi
+        echo "This script should be started by hald." >&2
+        exit 1
+fi
+
 hal_call_backend() {
     local PROGRAM
     PROGRAM="./$HALD_UNAME_S/$(basename $0)-$HALD_UNAME_S"
-- 
1.5.4.3