5 ms·

I'm not sure about all languages but this actually caught me by surprise. When you do a 'mv' command (tested on macos) it does not retain file permissions by de

• dmd 4y ago
  What? Yes it does. You are confusing mv and cp.
  • rileymat2 4y ago
    This is a pretty good example. Sure, we should know our tools, but This is not intuitive behavior if you don't know. https://superuser.com/questions/101676/is-there-some-difference-between-mv-and-cp-rm-the-old-file-on-unix https://superuser.com/questions/101676/is-there-some-differe... It is not until the last comment of the accepted answer that you get to the difference in permissions. (along with the answers that are not accepted as best)
  • mnw21cam 4y ago
    Or the parent could be trying to mv a file from one filesystem to another. In that case, mv will have to revert to a copy-then-delete operation, and the user may not have the permissions necessary to set up the new file with all the same metadata as the original.
    • dmd 4y ago
      Good point.
• dahfizz 4y ago
  Whatever library or tool you use will just call the `rename` syscall. As you would expect, rename simply renames a file. It deletes the old directory entry and creates a new one. If you're using a library or tool to do this for you, you should know what it's doing.