Routine of RAM size evaluation not sufficient and might cause issues

[luddinho]

Environment

script version: v3.0.56
OS: DSM 7.2
Device: 1817+
RAM: 2x 8GB

Problem description

The evaluation of RAM size might cause issues because the condition of the grep command for dmidecode is not clear enough.

Example:
On my system the command dmidecode -t memory | grep "[Ss]ize" will return the following content.

Size: 8192 MB
Size: No Module Installed
Size: 8192 MB
Size: No Module Installed

Now you can imagine what will happen with the variables $ramsize and $bytes when evaluating with awk.

ramsize=$(printf %s "${array[num]}" | awk '{print $2}')
bytes=$(printf %s "${array[num]}" | awk '{print $3}')

The result is:

ramsize: 8192
bytes: MB
ramsize: No
bytes: Module
ramsize: 8192
bytes: MB
ramsize: No
bytes: Module

At the end of the loop we will have fortunately the correct numeric value for the variable $ramtotal. But the unit for $bytes is inconsitent.

ramtotal: 16384
bytes: Module

Proposed solution

My proposal is to make the grep command with an extended regular expression much more precise that will return only the size with numeric values and additionally with a valid unit either MB or GB as postfix at the end of the line.

#Proposal
dmidecode -t memory | grep -E "[Ss]ize: [0-9]+ [MG]{1}[B]{1}$"

# Return
Size: 8192 MB
Size: 8192 MB

I haven´t checked other systems yet, but it could also lead to an error in the calculation of $ramtotal size.
Please have a look and check if the improvement can be implemented.

[007revad]

Nicely formatted issue, and nice solution. Thank you.

[luddinho]

From a code review so far, it looks pretty good. I think this is fine now.

Thanks for the fix.