ps and username size

[Tito]

On Thursday 10 January 2008 22:40:26 Cristian Ionescu-Idbohrn wrote:
> On Thu, 10 Jan 2008, Tito wrote:
> 
> > Isn't there a maximum lenght for usernames on unix/linux?
> > Would it make sense to set the width of this field to that value?
> 
> Doing so seems like the clever thing to do, though you'd run into a
> columnisation problem and loose compatibility to full version of the app.
> 
> > I ask this because on my system (Ubuntu 7.10 - more or less)
> > adduser  fails with usernames longer than 32 chars.
> >
> > Adding user `qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq' ...
> > Adding new group `qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq' (1006) ...
> > groupadd: qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq is not a valid group name
> > adduser: `/usr/sbin/groupadd -g 1006 qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq' returned error code 3. Exiting.
> 
> 32 chars seems reasonable, but display real estate seems to be a problem.
> I believe truncated usernames vs. option to display user ids only seems to
> be an acceptable compromise.  What do you think?
> 
> 
> Cheers,
> 

Hi,
of course it is acceptable.

OTOH it doesn't solve the problem of a possible ambiguity
between username and uid as names composed only of digits
are legal.

One simple idea to solve this would be to prepend uid=
when using uids instead of to long usernames.

root           6643  0.0  0.0  13120   1564 ?        Ss      20:40   0:00 /usr/sbin/gdm
root           6652  0.0  0.0  13564   2868 ?        S        20:40   0:00 /usr/sbin/gdm
root           6654  1.2  1.5  68216 63216 tty7   SLs+  20:40   1:49 /usr/bin/X :0 -
uid=440  11376  0.0  0.0    4140  1760 pts/2  Ss       22:54   0:00 /bin/bash
dnsmasq   6671  0.0  0.0    2236    772 ?        S         20:40   0:00 /usr/sbin/dnsma
root           6722  0.0  0.0    2828    684 ?        Ss        20:40   0:00 /usr/bin/dirmng


The pros:
1) the prefix is short and plus the size for the uid will not use more than (uid=65000) 9-10 chars field width.
2) the = sign is not allowed in usernames so no more ambiguity.
                   adduser uid=123
                   adduser: To avoid problems, the username should consist only of
                   letters, digits, underscores, periods, at signs and dashes, and not start with
                   a dash (as defined by IEEE Std 1003.1-2001). For compatibility with Samba
                   machine accounts $ is also supported at the end of the username
The contras:
1) this breaks all standards of the world and the compatibility with gnu ps.


Just one more idea  :-)

Ciao,
Tito