~/tutorials/007-finding-things.md

007: Finding things

Three tools, three different questions. tree draws the whole map. find searches names. grep searches inside files, and it only works at the end of a pipe.

The map

tree | head -8

One screen, the whole shape. Six directories at the time of writing, and tree | grep / | wc -l is how you stop having to trust me.

Names

find tutorials
find flag

find takes one term and matches it against every name, quietly, without caring about case: find Flag finds the same things. It answers with paths, which lesson six made cheap.

Names that begin with a dot are a different matter. ls does not show them, and neither does find. ls -a shows the ones where you stand, because a file nobody can list is a file nobody finds.

Lines

ls ~/news | grep -i router
cat ~/news/2026-09-10-mikrotik-routeros-privilege-escalation.md | grep -i router | wc -l

grep keeps the lines that match. With -i it ignores case, which matters more than it sounds: the same idea written Router, router and ROUTER is one idea. The two commands above disagree on purpose. One name matched. Inside the file, seven lines did. <!-- claim: 1 = ls ~/news | grep -i router | wc -l --> <!-- claim: 7 = grep -i router ~/news/2026-09-10-mikrotik-routeros-privilege-escalation.md | wc -l --> find answers where something is called something. grep answers where something is said. Most questions are one of those two.

Nothing

find zzzz

A find with no matches says so in one line. A grep with no matches says nothing at all, which is lesson one's first lie waiting to happen: printed nothing is not the same as nothing.

Try it

Each of these has one answer, and the shell gives it to you. Check yourself.

1. How many directories are there? One tree, one grep, one count.
2. How many markdown files exist in the whole tree? find accepts any part of a name.
3. Which news files say cve somewhere inside, not just in the name? cat, a pipe, and reading what comes back.
4. Ask find for something that does not exist, then ask grep the same way. Read both answers.

Counts here go stale as the tree grows, this lesson included. That is not a bug in the lesson. Run the command and you have the current truth.