chmod -R -r not working on macOS High sierra

1

I've upgraded from El Capitan to High Sierra (beta 9). On El Capitan, running the command chmod -R -r <path to dir> works fine (revoking read permissions recursively). On High Sierra I get the non-sense error message chmod: <path to dir>: Permission denied.

Note that additive commands like chmod -R +r <path to dir> do work fine on High Sierra.

I tested this on the main system volume of my internal MPB disk (APFS file system, because the installer converts HFS+ volumes automatically on SSDs) and on a HFS+ RAM-disk. The behavior was the same.

Is this worthy of a bug report to Apple? Am I missing something?

NameZero912

Posted 2017-09-24T08:58:28.213

Reputation: 151

1Any folder, or specific? I'm thinking SIP... – Tetsujin – 2017-09-24T09:01:27.450

1Is it possible that High Sierra starts doing the permission changes at the TOP folder first? Meaning, maybe it actually removed the read permissions at the top folder, and that prevented chmod from descending any further? – jimtut – 2017-09-25T13:38:52.087

Hm, after a few more tests I found that the issue is also there with El Capitan. I'm addressing a normal empty folder I have created, on which I (by default) have the permissions drwxr-xr-x (so, 755 essentially). Let's say that folder is located at /tmp/somefolder, then chmod -R -r /tmp/somedir always fails (regardless whether it has child objects or not), while sudo chmod -R -r /tmp/somedir succeeds. Why do I need sudo/admin-permissions to recursively remove read permissions from a dir?!? – NameZero912 – 2017-09-26T07:23:27.050

After some more experimentation I can say that, even though chmod -R -r /tmp/somedir fails, the read-permissions are revoked for /tmp/somedir, but not for any sub-directories (in case there are any) - sudo is required to really perform the permission-change recursively. It makes no sense at all, and suggests that chmod is implemented very poorly (and that was never discovered for some reason... it just can't be true!). It seems to me that chmod first applies the operation to the very highest-level directory and then fails to apply it to sub-dirs (and even fails if there aren't any). – NameZero912 – 2017-09-26T07:41:07.577

find <path> -d -exec chmod -r {} ";" is the way to go. – NameZero912 – 2017-09-26T10:29:24.917

No answers

Asked: 2017-09-24T08:58:28.213

Viewed: 1 942 times

Active: 2017-09-24T08:58:28.213