On Thu, Dec 2, 2010 at 8:04 PM, Genes MailLists <lists@xxxxxxxxxxxx> wrote: > On 12/02/2010 07:42 PM, Marko Vojinovic wrote: >> On Thursday 02 December 2010 21:02:17 Aaron Konstam wrote: >>> On Thu, 2010-12-02 at 18:10 +0100, Joachim Backes wrote: >>>> Can somebody explain why pure numbers are allowed for username in the >>>> useradd command? >>>> >>>> sudo useradd 123456789 >>>> >>>> is not rejected! >>>> >>>> As is known, this leads to big problems if referring to such a user and >>>> the username differs from the userid: should such a username be >>>> interpreted as username or userid? > > Can you be specific - what big problems are these ? Never tried, but > it is by means obvious that this would be problematic. > >> So I guess 12345 should be a valid username as any other, and useradd >> correctly allows for creation of such usernames. No bug there. > > Agreed - without knowing what the problems are it is hard to say that > useradd (or anything else) should disallow numerical id's .. In Solaris, there are restrictions on the username. It has to start with a letter, cannot start with a hyphen, and cannot contain a colon. (There may be more restrictions; these are the ones that I remember.) I've always assumed that Linux had the same restrictions but "man 5 passwd" on my F14 box yields nothing so I've just googled and the only restriction that http://www.kernel.org/doc/man-pages/online/pages/man5/passwd.5.html sets is "It should not contain capital letters". -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines
