Comment # 1 on bug 932950 from Dr. Werner Fink

man w(1) ...

ENVIRONMENT
       PROCPS_USERLEN
              Override the default width of the username column.  Defaults to
8.

       PROCPS_FROMLEN
              Override the default width of the from column.  Defaults to 16.

and man utmp(5)


           #define UT_LINESIZE      32
           #define UT_NAMESIZE      32
           #define UT_HOSTSIZE     256

           struct utmp {
               short   ut_type;              /* Type of record */
               pid_t   ut_pid;               /* PID of login process */
               char    ut_line[UT_LINESIZE]; /* Device name of tty - "/dev/" */
               char    ut_id[4];             /* Terminal name suffix,
                                                or inittab(5) ID */
               char    ut_user[UT_NAMESIZE]; /* Username */
               char    ut_host[UT_HOSTSIZE]; /* Hostname for remote login, or
                                                kernel version for run-level
                                                messages */

Beside this: openSUSE 12.3 is gone