mjhjmtu

My flavor of grep supports --group-separator and --no-group-separator but I only discovered this by googling how to solve a problem:

https://stackoverflow.com/questions/2168065/how-do-i-get-rid-of-line-separator-when-using-grep-with-context-lines

I tried:

grep --help | grep separator

and

man grep
/group-separator

with no results.

Where would I have found this information without Google and Stack Exchange?

Documentation of most GNU utilities is primarily written in texinfo format, from which are derived the info pages, HTML documentation and formats for printing like PDF or postscript.

For interactive browsing, that's generally the info format you want. texinfo documentations borrows the table-of-content and index concepts from books. In info, the native GNU utility to browse info documentation, you can query the table of contents (the various nodes of the documentation) with g, and the index with i. Completion is available for both.

So here, I'd do:

info grep

And within info, press i to bring up the index prompt, type group and then press Tab to see the possible completions. That brings group separator straight away. If it hadn't, if there had been no index entry for it for instance, you could have search the entire text with s.

You can also invoke info as:

info --index-search=group-separator grep

Or press I instead of i to get a virtual text node with the list of index entries that match your query.