Changing the user name

[Laszlo Papp]

On Wed, May 14, 2014 at 1:38 PM, Tito <farmatito at tiscali.it> wrote:
> On Wednesday 14 May 2014 12:33:45 you wrote:
>> On Tue, May 13, 2014 at 8:27 PM, Tito <farmatito at tiscali.it> wrote:
>> > On Tuesday 13 May 2014 19:01:41 Laszlo Papp wrote:
>> >> Hi,
>> >>
>> >> is this possible? I am looking for something like "usermod -l" on desktop.
>> >
>> > This is actually not supported by busybox.
>> > So far we are able to add and delete users or groups
>> > or add users to groups or delete users from groups.
>>
>> Is that by design or no one has stepped up yet doing the work?
>
> I suppose nobody needed that feature so far.

OK, let us say I need this feature:

* Is it acceptable to add it to busybox (at least with some configuration)?

* Where would it fit, adduser, separate applet or somewhere else?

>> >> Alternatively, I have to look into the get/setpwent syscalls?
>> >
>> > Yes.  You can take a look at libbb/update_passwd.c for inspiration
>> > and you need to be root to perform the user name change.
>>
>> It does not seem to use setpwent/getpwent though. It seems to be
>> fiddling with manual file opening and so on. Why is it like that?
>
> I think editing on a per line basis is easier in that you can simply
> write the untouched lines to the new file and edit the field
> of the line of interest without touching other fields.

Fair enough, albeit there could have been a serialization posix method
out of the passwd structure creating the string for convenience...