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Lessons · Terminal · grep -i: however it was typed

However it was typed

-i ignores case, which is usually right for anything a human wrote and wrong when the case IS the fact.

Hone is a place to practise programming. This is one of its lessons, written out in full and free to read without an account.

What it is for

Logs written by several services spell the same level three ways.

How to think about it

Default to -i on human text; leave it off when ERROR and Error mean different things.

Worked example

grep -c error mixed.log
1. Only the lowercase one.
grep -ci error mixed.log
3. Flags combine, and -c is still lines.
grep -i error mixed.log
All three, so you can see what you counted.

Your turn

Find log however it was capitalised.

grep  LOG app.log

The trap

On a log that uses ERROR for failures and Error for warnings, -i merges the two things you were asked to tell apart.

Practise grep -i: however it was typed on HoneA question on it now, a coding challenge where there is one, and it is remembered for review. Free, no email needed.