I want to show all lines before a match, not only 10, or 7, or 14 for example, as explained in How do I fetch lines before/after the grep result in bash?.
How can I do it? It doesn't matter if the matched line is included or not.
For example, instead of:
... | grep -B 10 -- "foo"
... | grep -B -- "foo"
But this last code doesn't work.