--- run-crons.stock	2014-11-24 16:45:17.822842446 +0100
+++ run-crons.n	2014-11-24 16:46:39.554102904 +0100
@@ -37,7 +37,8 @@
 
 # Make sure we're not running multiple instances at once.
 # Try twice to lock, otherwise give up.
-for ((i = 0; i < 2; i = i + 1)); do
+i=0
+while [ "$i" -lt 2 ]; do
 	ln -sn $$ ${LOCKFILE} 2>/dev/null && break
 
 	# lock failed, check for a running process.
@@ -54,6 +55,7 @@
 	else
 		rm -f ${LOCKFILE}
 	fi
+	i=$(($i+1))
 done
 
 # Check to make sure locking was successful