New folders are created with `0755` permission

[dipterix]

I'm aware of the discussion here https://github.com/r-lib/fs/issues/293

Today I encountered this issue. I was running an R script on my server. I set my system default umask to be 077 (https://support.apple.com/en-us/101914), and Sys.umask() is "77", hoping that the code would respect that (I also have ACL set up on the project folder so normally only the code owner and user group permitted by ACL can run commands. However, packages depending on fs generated bunch of 0755 files (because my account has the admin (not root) privilege).

This incident raised my concerns. You see the people who wrote the code might not be the same group of people who actually run the code, especially for R package authors. Most people who use fs because it is a powerful substitute (indeed it is) to the base functions. It has almost no learning curve. People who are already familiar with base functions can easily transfer to fs with no significant differences

However, such "naive" assumption might cause problems. The code authors might not know how chmod, umask, ACL work (they don't need to). People who know the permissions might also give upthinking and rely on fs being consistent (since fs is too similar to base functions and too easy to use).

My suggestion is maybe fs always respect Sys.umask, and can be turned off via options. For most users this won't change their experience as most system default umask is 022.

Alternatively users can instruct whether to respect Sys.umask by wrapping the mode

fs::dir_create("dir", mode = "0777", umask = Sys.umask())

# or

fs::dir_create("dir", mode = fs::safe_mode("0777"))
safe_mode <- function(mode, umask = Sys.umask()) {
  ...
}

Then all the code that tries to change to mode to 0777 is constrained by user-controlled umask