Re: [PATCH 3/3] Revert "bash prompt: avoid command substitution when finalizing gitstring"

> Brandon Casey <bcasey@nvidia.com> writes:
>
>> From: Brandon Casey <drafnel@gmail.com>
>>
>> This reverts commit 69a8141a5d81925b7e08cb228535e9ea4a7a02e3.
>>
>> Old Bash (3.0) which is distributed with RHEL 4.X and other ancient
>> platforms that are still in wide use, does not have a printf that
>> supports -v.  Let's revert this patch and go back to using printf
>> in the traditional way.
>>
>> Signed-off-by: Brandon Casey <drafnel@gmail.com>
>> ---
>
> Is this something you can detect at load-time once, store the result
> in a private variable and then switch on it at runtime, something
> along the lines of...
>
>
>         # on load...
>         printf -v __git_printf_supports_v -- "%s" yes >/dev/null 2>&1
>
>         ...
>
>         if test "${__git_printf_supports_v}" = yes
>         then
>                 printf -v gitstring -- "$printf_format" "$gitstring"
>         else
>                 gitstring=$(printf -- "$printf_format" "$gitstring")
>         fi

>>  contrib/completion/git-prompt.sh | 6 +-----
>>  1 file changed, 1 insertion(+), 5 deletions(-)
>>
>> diff --git a/contrib/completion/git-prompt.sh b/contrib/completion/git-prompt.sh
>> index a81ef5a..7698ec4 100644
>> --- a/contrib/completion/git-prompt.sh
>> +++ b/contrib/completion/git-prompt.sh
>> @@ -433,11 +433,7 @@ __git_ps1 ()
>>       local gitstring="$c${b##refs/heads/}${f:+$z$f}$r$p"
>>
>>       if [ $pcmode = yes ]; then
>> -             if [[ -n ${ZSH_VERSION-} ]]; then
>> -                     gitstring=$(printf -- "$printf_format" "$gitstring")
>> -             else
>> -                     printf -v gitstring -- "$printf_format" "$gitstring"
>> -             fi
>> +             gitstring=$(printf -- "$printf_format" "$gitstring")
>>               PS1="$ps1pc_start$gitstring$ps1pc_end"
>>       else
>>               printf -- "$printf_format" "$gitstring"