I've created a 09_custom script that has been working sort of until now. Now, I'm getting a syntax error when I try running update-grub. If anyone can help, I would greatly appreciate it. Here is the code snippet causing the syntax error:
Each variable contains an md5sum of the initrd or vmlinuz file in the boot directory. I'm just trying to make sure they were read correctly from the SSD and I can safely boot from them.
The second if statement is causing the syntax error.

if [ "${vmlinuzmd5}" != "${catvmlinuzmd5}" ] ; then
if [ "${2vmlinuzmd5}" != "${2catvmlinuzmd5}" ] ; then
echo "kernel image is corrupted.";

Thank you,
Respectfully,
sharkman.

OK, I have resolved this issue. Variables cannot start with a digit. I changed the names of the variables slightly and all is good.

Thank You,
Respectfully,
sharkman.