I escaped the dot correctly and sed still rewrote a file marked DO NOT CHANGE

Tue, 13 Oct 2026 13:00:00 +0000

Four config files, one hostname to rename. I knew the dot in api.internal is a regex wildcard, so I escaped it. grep -rn 'api.internal' unescaped matched a fourth file containing apiXinternal — a typo somebody deliberately kept. Escaped, api\.internal matched three. Good.

Then I ran the rename, and two of those three should never have changed: a line ending in # DO NOT CHANGE, and a commented-out sample. My -not -path "*/samples/*" exclusion did nothing, because the file was called sample.conf and was not inside a samples/ directory.

That is the real lesson, and escaping was never the whole answer. The dot is the trap everyone warns about; the trap that actually got me was assuming my exclusion pattern matched what I pictured. The fix is an order, not a flag — make grep -l print the file list while everything is still read-only, and read it:

find /etc/myapp -type f -name "*.conf" -exec grep -l "api\.internal" {} +

If that list surprises you, the surprise is the bug, and you found it before anything was written. Only then pipe it to sed -i.bak, so every file keeps a rollback copy — and diff one against its .bak before trusting the run. sed -i exits 0 whether it changed four files or none.

The awk summarizing stage and the incident-triage pipeline are in the find, grep, sed and awk ordering guide.

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I escaped the dot correctly and sed still rewrote a file marked DO NOT CHANGE