Rejecting device names which are not a single word

xorriso-dd-target/xorriso-dd-target

@@ -212,9 +212,16 @@ arg_interpreter() {
       exit 0
     elif echo "$i" | grep -v '^-' >/dev/null
     then
-      devs_named=y
-      devs="$devs $i"
-      show_reasons=y
+      num=$(echo "$i" | wc -w)
+      if test "$num" = 1
+      then
+        devs_named=y
+        devs="$devs $i"
+        show_reasons=y
+      else
+        echo "$0 : Given device name is not a single word: '$i'" >&2
+        exit 12
+      fi
     else
       echo "$0 : Unknown option: $i" >&2
       echo >&2