Lennart, thank you,

I set grep-use-null-device to nil, but the problem still happen.

Maybe I shall trace the code to find how to avoid grep-probe. There is no
switch to turn off (grep-compute-defaults) in grep, because different
versions of grep. But I think most of people work on Linux and Gnu grep. So
why not have a switch tell it do not compute defaults?

On Tue, Sep 7, 2010 at 9:24 AM, Lennart Borgman
<lennart.borgman@gmail.com>wrote:

> Use customize to set the needed values, for example:
>
>  M-x customize RET grep-use-null-device RET
>
>
> On Tue, Sep 7, 2010 at 3:05 AM, Shenli Zhu <zhushenli2@gmail.com> wrote:
> > Hi, Lennart, how to skip grep-probe/grep-compute-defaults (add hook or
> > change variable)?
> >
> > Thanks
> >
> > On Tue, Sep 7, 2010 at 8:24 AM, Lennart Borgman <
> lennart.borgman@gmail.com>
> > wrote:
> >>
> >> On Tue, Sep 7, 2010 at 2:22 AM, Shenli Zhu <zhushenli2@gmail.com>
> wrote:
> >> > Hi Peter,
> >> >
> >> > Do you mean the grep-command I set should be runnable in shell? I just
> >> > use
> >> > grep-command to store the grep template, so it cannot be run in shell.
> >> >
> >> > Why we need probe-grep? To test whether grep exists and whether its
> >> > function
> >> > works correctly? Can I skip it?
> >>
> >>
> >> probe-grep tries to find out what grep program you actually use and
> >> what it can do. So, yes, you can skip it if you know what the program
> >> can do.
> >
> >
>