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
grep selects lines. sed edits a stream. awk splits fields. The builders draft one command each. They do not change a host. sed -i is an edit of a file, so the first draft has no -i. You edit a copy.
The file is one you are allowed to read. Do not run these across /etc as a guess. Do not use them to collect secrets from a host you do not administer. A pattern that is meant to evade a control is not a pattern you are writing.
Quotes matter. A pattern with a space and no quotes is a different command. Read the draft aloud. 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 file and the question.
- Pick grep, sed, or awk.
- Draft one command.
- Reject sed -i on the first draft.
- Do not run it during the reading.
- Stop.
Mistakes that outlive the command
grep, sed and awk Explained goes wrong in a small set of ways. The list is here so the ticket can forbid them before the window.
- sed -i on the only copy.
- A search of a host you do not administer.
- A pattern written to evade a filter.
- Three tools in one command you cannot read.
- Secrets copied into the ticket.
Decisions to write down
One decision for grep, sed and awk Explained: One tool. The file is yours to read. The first sed has no -i. The draft was read aloud. And nothing was run yet.
Checks before you call it done
Confirm this before you call the change done: The file is named. One tool is chosen. No -i is in the first draft. No secret is in the note. And nothing was run. If one of those fails, stop.
# grep finds. sed streams. awk splits.
# No sed -i on the first draft.
# A file you may read.Before you leave the host
grep, sed and awk Explained 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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