[ale] grep

[Brett Becker]

Is there any non-shell script way to make grep return just the line
numbers of matches and not the content of the line?

For example,

grep -n will return something like this:

11:	exec ls
36:     exec foo 

All I want are the line numbers and I do not want to have to use any sort
of shell script to chop of the ends.

If this is not possible, how would it be done with a shell script?

Thanks,
Brett B.