bug#9987: [PATCH] groups,id: add -0, --null option

[Pádraig Brady]

On 09/17/2013 12:19 AM, Pádraig Brady wrote:
> On 09/16/2013 11:21 PM, Bernhard Voelker wrote:
>> On 09/16/2013 07:40 AM, Bernhard Voelker wrote:
>>> On 09/16/2013 02:18 AM, Pádraig Brady wrote:
>>>> Yes please use -z, --zero for most consistency.
>>>
>>> Ok, fine, thanks.
>>
>> Here comes the new patch with {groups,id} -z,--zero.
>>
>> Have a nice day,
>> Berny
>>
> 
> Very nice.
> I can't find any issues with that at all.

Actually omitting the trailing \0 could be
inconsistent and problematic?


uniq and basename for example always output the trailing \0

$ basename -az 1/1 2/2 | od -Ax -tx1z -v
000000 31 00 32 00                                      >1.2.<
000004

$ printf "1\0002" | uniq -z | od -Ax -tx1z -v
000000 31 00 32 00                                      >1.2.<
000004


Also handling only separated output in shell can be awkward:

# This is OK:
$ groups | tr ' ' '\n' |  while read group; do echo $group; done | wc -l
4

# This drops the last item
$ groups -z | tr '\0' '\n' | while read group; do echo $group; done | wc -l
3

cheers,
Pádraig.