Check for non-zero number of arguments for safety reasons.

truncate/truncate.sh

@@ -1,7 +1,12 @@
 #!/bin/sh
+if [ $# -eq 0 ]
+then
+    echo "Usage: $0 find-options" >&2
+    exit 1
+fi
 @@@find_printf@@@ "$@" -type f -printf '%TY%Tm%Td%TH%TM.%TS %p\n' |
 while read timestamp file
 do
-    echo -n "" > "$file"
+    : > "$file"
     touch -t "$timestamp" "$file"
 done