How to get the installer path/name from the MAC UI installer(.pkg) start page

Question

We are trying to fetch installer path/name from the MAC UI installer before displaying the Custom nib file.
Below are the options tried:

• hdiutil info -plist
• Getting the environment variable $PACKAGE_PATH
• Scanning the current directory
• ps -eaf for listing the installer process name.

Answer 1

I needed to perform the same task today and the best approach I've discovered is to tail or cat the /var/log/install.log file just after the pkg is launched & grep for ".pkg".

tail /var/log/install.log | grep ".pkg"

This prints the path & name of the most recently launched pkg file. From there, I can parse the line of the last occurrence to extract my own installer's path & name:

2022-04-21 12:50:01-04 mbp Installer[29570]: Opened from: /Users/[myuser]/Downloads/[myPkgFile].pkg
2022-04-21 12:50:01-04 mbp Installer[29570]: Product archive /Users/[myuser]/Downloads/[myPkgFile].pkg trustLevel=350

Note: So far, I've only tested this on Big Sur 11.6. The log syntax may differ on older or newer versions. I expect, though, that it hasn't changed much over the years.