How does one go about changing the maximum from 8 to a higher number where more
than 8 are significant. having numbers in arbitrary user ids drives my users nuts.
Dave Mielke wrote:
> On Wed, 3 Feb 1999, Trevor Reynolds wrote:
> >Is there a "true" limit on the length of a Userid in linux?
>
> In UNIX, there is no formal maximum for the length of a userid, although it is
> guaranteed to be no less than 8. You can ask your system what its maximum is by
> compiling and running the following program:
>
> #include <stdlib.h>
> #include <unistd.h>
> #include <stdio.h>
> int main (int argc, char **argv) {
> printf("%d\n", sysconf(_SC_LOGIN_NAME_MAX));
> return 0;
> }
>
> On my system, for example, this program prints 9, which, allowing for a
> trailing null byte, means that my maximum userid length is 8.
>
> Even if your system allows for a longer userid, it's still best not to exceed 8
> as some old mailers have trouble with userids which are longer than that.
>
> >but some interfaces,
> >like webmin, will let you add users with as many characters as you want,
>
> Technically, userids can be longer than the maximum, but the extra characters
> are not significant. Also, since some programs may use SYSCONF to determine how
> large to allocate a buffer, having userids which are too long could cause
> buffer overruns.
>
> --
> Dave Mielke | 856 Grenon Avenue | I believe that the Bible is the
> Phone: 1-613-726-0014 | Ottawa, Ontario | Word of God. Please contact me
> EMail: [EMAIL PROTECTED] | Canada K2B 6G3 | if you're concerned about Hell.
