Re: RFC "grep '...\{m,n\}"?

> "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> writes:
>
>> diff --git a/t/t3404-rebase-interactive.sh b/t/t3404-rebase-interactive.sh
>> index 8197ed29a9ec..a31f7e0430e1 100755
>> --- a/t/t3404-rebase-interactive.sh
>> +++ b/t/t3404-rebase-interactive.sh
>> @@ -1039,4 +1039,11 @@ test_expect_success 'short SHA-1 collide' '
>>       )
>>  '
>>
>> +test_expect_success 'respect core.abbrev' '
>> +     git config core.abbrev 12 &&
>> +     set_cat_todo_editor &&
>> +     test_must_fail git rebase -i HEAD~4 >todo-list &&
>> +     test 4 = $(grep -c "pick [0-9a-f]\{12,\}" todo-list)
>> +'
>
> Documentation/CodingGuidelines says
>
>  - As to use of grep, stick to a subset of BRE (namely, no \{m,n\},
>    [::], [==], or [..]) for portability.
>
>    - We do not use \{m,n\};
>
>    - We do not use -E;
>
>    - We do not use ? or + (which are \{0,1\} and \{1,\}
>      respectively in BRE) but that goes without saying as these
>      are ERE elements not BRE (note that \? and \+ are not even part
>      of BRE -- making them accessible from BRE is a GNU extension).
>
> but I see we have multiple hits from "git grep 'grep .*\\{'" (all in
> the t/ directory).  I wonder
>
>  - if everybody's system is now OK with \{m,n\} these days, or
>
>  - there are people who are grateful that we stayed away from using
>    \{m,n\} but they are not running the tests because their system
>    is too exotic to pass other parts of the test suite.