Calculate Free Space - Catalina

[JefferyAnderson]

I'm trying to calculate free space on Catalina. For prior versions of macOS, this piece from a script from Joshua Roskos' macOS Upgrade script works:

diskInfoPlist=$(/usr/sbin/diskutil info -plist /)
    ## 10.13.4 or later, diskutil info command output changes key from 'AvailableSpace' to 'Free Space' about disk space.
    freeSpace=$(
    /usr/libexec/PlistBuddy -c "Print :FreeSpace" /dev/stdin <<< "$diskInfoPlist" 2>/dev/null || /usr/libexec/PlistBuddy -c "Print :AvailableSpace" /dev/stdin <<< "$diskInfoPlist" 2>/dev/null
    )

But on Catalina, the result is "0" every time. The FreeSpace key that is generated by:

/usr/sbin/diskutil info -plist /

is always "0" on Catalina. What needs to be changed to get the correct value for FreeSpace?

[PaulHazelden]

Hi I use....

df -m /Volumes/Macintosh HD | awk '{print $4}' | grep -v "Available"

And it shows the number of Mb available, divide by 1024 to get Gb

[rcole]

This is interesting and helfpful @PaulHazelden  — Is this able to be used in Big Sur as well as Catalina as an extension attribute with as an Integer? 

[PaulHazelden]

Yes the code works in Big Sur, it is Bash. You would need to set it up to publish its results to make it into an EA.

I use it to report space to the user with a notification popup. Our Macs get a lot of the user space cleared out every day, but some of the students working on Movies can get a bit carried away and drop a serious amount of files on the hard drive. So they get warnings.