Add is_set function to make checking boolean variables easier.

The definition of a boolean variable is one that is set to "true", "yes" "1",
or that is set to the null value.

1 files changed, 13 insertions, 1 deletions

diff --git a/pm/functions.in b/pm/functions.in
index bd0705c..fab9b38 100644
--- a/pm/functions.in
+++ b/pm/functions.in
@@ -3,8 +3,19 @@
 
 # Common functionality for the hooks.
 
+# If a variable is set to true, yes, 1, or is simply set with no value,
+# return 0, otherwise return 1.
+is_set()
+{
+    case ${1-UNSET} in
+	[Tt][Rr][Uu][Ee]|[Yy][Ee][Ss]|1|'') return 0;;
+	*) return 1;;
+    esac
+}
+
 # for great debugging!
-[ "${PM_DEBUG}" = "true" ] && set -x
+is_set "${PM_DEBUG}" && set -x
+
 
 # try to take the lock.  Fail if we cannot get it.
 try_lock()
@@ -246,3 +257,4 @@ dbus_send ()
 {
 	command dbus-send "$@" 2>/dev/null || return $NA
 }
+