Script not fully compatible with Bash < 4.2

[sebastien-prudhomme]

Hi,
My environment is RHEL6 (with Bash 4.1.2) and i've got this error:

line 111:  -2: substring expression < 0

This syntax is not valid in Bash < 4.2:

free=${freeunit:0:-2}

(negative length is working since Bash 4.2 only)

To make it work:

free=${freeunit:0:${#freeunit}-2}