How to grep ‘—‘ in Linux? grep: unrecognized option ‘—‘

Question

This happens because grep interprets --- as an option instead of a text to look for. Instead, use --:

grep -- "---" your_file

This way, you tell grep that the rest is not a command line option.

Other options:

use grep -e (see Kent’s solution, as I added it when he had already posted it – didn’t notice it until now):
use awk (see anubhava’s solution) or sed:
```
sed -n '/---/p' file
```

-n prevents sed from printing the lines (its default action). Then /--- matches those lines containing --- and /p makes them be printed.