[Ovirt-devel] Re: a pox on whitespace

[Jim Meyering]

"Hugh O. Brock" <hbrock at redhat.com> wrote:

> On Wed, Jul 16, 2008 at 07:21:46PM +0200, Jim Meyering wrote:
>> Here are some things we can do to avoid
>> bad whitespace (not just trailing whitespace)
>> without causing too much development pain:
>>
>> server-side enforcement
>>   have a git pre-push hook check for and reject changes that
>>   add trailing blanks.  This typically cannot be circumvented.
>>   However, I've set up similar things whereby exceptional cases
>>   can be white-listed.
>
> I'd be in favor of putting this into place immediately.
>
>> local-commit-enforcement
>>   With recent git, just do this in each of your
>>   working directories:  chmod a+x .git/hooks/pre-commit
>>   and a commit that would have added bad whitespace will fail.
>>   (you can circumvent it with git commit's --no-verify (-n) option)
>
> And this... how recent a git version?

Actually it goes back farther than I thought,
so we should all have this:
To check, run this:

  grep whitespace .git/hooks/pre-commit

if it shows something like this, then enable it via
"chmod a+x .git/hooks/pre-commit"

  # Lines you introduce should not have trailing whitespace.
                  bad_line("trailing whitespace", $_);

>> "make check"-style detection
>>   Add a top-level Makefile rule that fails if any file
>>   contains bad whitespace.  Then establish policy that one must
>>   pass "make check"s tests before committing/pushing.
>
> This is probably less compelling for us since we don't really compile
> the app (although I habitually still run make and then install the RPM
> to test changes).
>
>> editor highlighting
>>   Enable syntax highlighting in your editor and tell it to
>>   display bad whitespace.  For example, add this to your ~/.vimrc:
>>
>>     let c_space_errors=1
>>     highlight RedundantSpaces ctermbg=red guibg=red
>>     match RedundantSpaces /\s\+$\| \+\ze\t/
>>
>> For emacs, you might want to try show-wspace.el (I haven't,
>> but it's the first google hit for "highlight whitespace emacs")
>> <http://www.emacswiki.org/cgi-bin/wiki/show-wspace.el>, or maybe
>> you already use font-lock mode, which you can customize.
>
> This is voluntary I guess but seems like a good thing for developers
> to do.
>
> Also needed might be a quick script to remove trailing whitespace from
> a file?

perl -pi -e 's/\s+$//' file1 file2 ...