chmod for human beings!

If UNIX octal permissions get you down, this is the tool for you. Humans were never meant to do bit arithmetic in their heads.

npm i -g remod-cli

You can view and interactively edit the permissions of a file with

$ remod foo.txt

If you think that you want to change a file's permissions to 640 but you'd like to preview the changes first, just run

$ remod 640 foo.txt