This is an original planning guide. It is not a vendor manual, an official standard, or legal advice. Example addresses use documentation ranges. Review every command before you paste it.
What this hour is for
chmod changes the mode bits. chown changes the owner and the group. They solve different mistakes. A file that is owned by the right user and mode 600 is not the same as a file that is mode 777 and owned by whoever was handy.
The chmod calculator shows symbolic and numeric modes, including the special bits. The chown builder drafts a command. Neither tool changes a file on a host. You still name the path.
644 is a normal file others may read. 755 is a normal directory or a program others may execute. 600 is a private key or a shadow-style file. 777 is the mode you are not choosing. SUID, SGID, and the sticky bit have their own guide. Do not set them here because a program failed to start.
Do not chown a system path to a login user to make a service write there. Give the service its own directory and its own account. 192.0.2.10/24 and example.com are documentation. They stay in the note.
The change you can finish
Apply nothing while you are writing the note. When the lab window opens, it is one change on the host named in the ticket. Read the draft, then the host, then decide.
Rollback is the file, the package version, or the snapshot you saved first. You do not invent a rollback after the only copy is gone.
- Name the path and the host.
- Decide whether the problem is the mode or the owner.
- Draft the one command that matches.
- Reject 777.
- Do not apply it during the reading.
- Stop after that path.
Mistakes that outlive the command
chmod vs chown goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.
- chmod used when the owner was wrong.
- chown used when the mode was wrong.
- 777 as a test.
- A system directory given to a login user.
- A special bit set on this page.
Decisions to write down
One decision for chmod vs chown: The path is one file or one directory. The change is mode or owner, not both unless the ticket says both. 777 is rejected. The tools draft text and do not change the host. And the special-bits page owns SUID.
Checks before you call it done
Confirm this before you call the change done: The path is written. The mode or the owner is written. 777 was not chosen. No command was pasted during the reading. And a second person can say which tool applied. If one of those fails, stop.
| You meant | Command idea | Not this |
|---|---|---|
| Others may read a file | 644 | 777 |
| A private file | 600 | A world-readable key |
| The wrong account owns it | chown the named user | chmod 777 |
chmod is the mode. chown is the owner.
777 is not a test.Before you leave the host
chmod vs chown ends when the hostname in the prompt matches the hostname in the ticket. If it does not, you are on the wrong host. Stop. A command that succeeded on the wrong host is not progress.
The draft stays a draft until a person has read the names in it. A generator does not log into the host and does not know which disk is empty. You delete a line that names a host, a path, or an account you did not write down.
192.0.2.10/24, gateway 192.0.2.1, 198.51.100.0/24, 203.0.113.0/24, and 2001:db8::/32 are documentation. example.com is a documentation name. They belong in the note. They are not values you leave on a host because a draft included them.
prompt-for-this is a reminder that a secret is missing. It is not a password, a key, or a token you save in the ticket or in git. The real secret stays in the password store.
One change is the window. If two things move and the result is wrong, you will not know which one did it. The next change waits for its own page.
If the same step fails twice, stop for the day. The failure is the result. Adding a forum command beside a half-applied change produces a host nobody can rebuild. Restore the copy you took first.
A second person reads the hostname and the change aloud. If they cannot find them in the ticket, the note is not done. Silence is not agreement. Then leave the host alone.
This page is a planning guide. It is not a vendor manual, not an official standard, and not permission to touch a host you do not administer. You do not disable a firewall, AppArmor, or SELinux to make a check pass.
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