fgrep,grep and egrep

[Maurice McCarthy]

Have a look at

$ info grep

also (Assuming you have the info package installed.) This was the
original gnu documentation system created by Richard Stallman before
the World Wide Web was invented.

Use the down arrow to scroll down.
At " * Introduction " or any line beginning " * " press enter to go to
that section or node.
Press n for next node
Press p for previous node (or the left arrow)
Press u to go up a node
Press d to go the top of the info browser tree
Press / to begin a search
Press q to quit

Maurice