setsched: check for presence of dialog

Make setsched error out when the dialog binary is not found in the path.
Ubuntu does not install dialog by default and people are tripping over
it.

1 files changed, 10 insertions, 2 deletions

diff --git a/setsched b/setsched
index 4b7160f..d2397b0 100755
--- a/setsched
+++ b/setsched
@@ -4,6 +4,7 @@
 
 ADIR=/proc/litmus/active_plugin
 PDIR=/proc/litmus/plugins
+DIALOG=`which dialog`
 
 CHOICE=$1
 
@@ -16,9 +17,15 @@ fi
 ACTIVE=`cat $ADIR`
 
 if [ -z "$1" ]; then
+    # Check for presence of dialog, some distros don't install it by default.
+    if [ -z "$DIALOG" ]; then
+        echo "Error: The dialog utility cannot be found."
+        echo "       Please install the required package (dialog on Ubuntu)."
+        exit 2
+    fi
     TMP=`mktemp`
     (awk "{print \$1 \" 'Plugin'\"}" $PDIR | \
-    xargs  dialog --title "Select Plugin" --backtitle "Current: $ACTIVE"  \
+    xargs $DIALOG --title "Select Plugin" --backtitle "Current: $ACTIVE"  \
         --cancel-label "Cancel" --ok-label "Select Plugin" \
         --menu "Select a new plugin to run: " 15 60 6) 2> $TMP
     OK=$?
@@ -31,7 +38,8 @@ if [ -z "$1" ]; then
 fi
 
 
-echo "$CHOICE" > $ADIR
+echo "$CHOICE" > $ADIR 2> /dev/null || \
+    echo "Error: Cannot write to $ADIR. Do you have root privileges?"
 
 ACTIVE=`cat $ADIR`