vim vs. grep : external quickfix/error file

My usual trick of using vim with grep works well when single grep invocation is sufficient.

Yet quite often I end up piping one grep's output to another grep to refine the results. And that doesn't work with my old trick of wrapping the grep MethodName *.cpp into vim -c ":grep MethodName *.cpp" as the vim's internal grep doesn't support pipes.

Digging through the documentation I found that it is possible to accomplish and it fits well to my workflow.

Start grepping(*):

$ grep MethodName *.cpp # not fine enough...
$ grep MethodName *.cpp | grep -v rubbish # much better
    # and save to a file
$ grep -n MethodName *.cpp | grep -v rubbish > tmp1.out

N.B. -n to the grep is required as VIM needs line numbers to jump to the locations.

And now tell VIM to use the produced tmp1.out error file:

$ vim -q tmp1.out

or

$ vim -c ":cf tmp1.out"

or from inside running VIM:

:cf tmp1.out

Check the :h :cf for the official documentation.

(*) Obviously in the case it doesn't have to be grep - anything what produces similar output would do. I used once a perl script to generate VIM-compatible error file from diff output to preview potential merge conflicts.