Dangerous Commands

Inspect Permissions Before Changing Them

A file or directory has a permission issue, but recursive fixes could break more than they repair.

Command

namei -l /var/www/example/index.html

What changed

Nothing changes. The command shows permissions for each path component.

Danger

safe

When to use it

Use this before `chmod -R` or `chown -R` so you know which layer actually blocks access.

When not to use it

Do not use inspection as the final fix; it only identifies where the permission problem is.

Undo or recovery

No state is changed.

Expected output

A component-by-component permission and owner listing for the path.

demo script

Disposable terminal steps

ls -l /var/www/example/index.html
namei -l /var/www/example/index.html
stat /var/www/example/index.html

Terminal transcript Demo JSON

simulated output

What it looks like

disposable vessel

::fixture-ready::
$ ls -l /var/www/example/index.html
-rw-r----- 1 root root 14 Jun 25 13:19 /var/www/example/index.html
::exit-code::0
$ namei -l /var/www/example/index.html
f: /var/www/example/index.html
drwxr-xr-x root root /
drwxr-xr-x root root var
drwxr-x--- root root www
drwxr-x--- root root example
-rw-r----- root root index.html
::exit-code::0
$ stat /var/www/example/index.html
  File: /var/www/example/index.html
  Size: 14        	Blocks: 8          IO Block: 4096   regular file
Device: 0,158	Inode: 4           Links: 1
Access: (0640/-rw-r-----)  Uid: (    0/    root)   Gid: (    0/    root)
Access: 2026-06-25 13:19:21.772065763 +0000
Modify: 2026-06-25 13:19:21.772065763 +0000
Change: 2026-06-25 13:19:21.774065792 +0000
 Birth: 2026-06-25 13:19:21.772065763 +0000
::exit-code::0

YouTube Short

Inspect before you chmod.

Recursive chmod is tempting because it is fast. Inspect the path first so you fix the layer that is actually blocking access.

experiments

A/B tests to run

Metric: linkedin_comment_rate

A: Inspect permissions before changing them.

B: This is what I run before `chmod -R`.