What is Alternative Install Permissions in Xcode Build Settings?

Question

What does Alternative Install Permissions mean in Xcode Build Settings?

Xcode version
From 4.6.2 (4H1003) to 11.2.1 (11B500).

Where
TARGETS -> Build Settings -> Deployment -> Alternative Install Permissions

Default value
u+w,go-w,a+rX (both for Debug and Release)

Answer 1

“Alternative Install Permissions” are the file permissions to apply to all the files listed in the “Alternate Permissions Files” build setting. For example, you could use them to make certain files in your build product read-only. Note that these settings only apply when you build for Installing.

As for what u+w,go-w,a+rX means, it’s a symbolic file mode -- see chmod(1) for a full explanation. That one, translated, is “user (the file’s owner) can write, group and other (everyone else) cannot write, and all (everyone everyone) can read, and execute if the file is either a directory or already had execute permission set.” (The “execute” bit on a directory actually means “search”.) I think you could also use a numeric setting -- the above roughly translates to 755 -- but numeric settings have no equivalent to the “X” flag -- they either set the “execute” bit or they don’t -- and the symbolic ones are easier to read.