2.9BSD - /usr/include/utmp.h

   1: /*
   2:  * Structure of utmp and wtmp files.
   3:  *
   4:  * Assuming the number 8 is unwise.
   5:  */
   6: struct utmp {
   7:     char    ut_line[8];     /* tty name */
   8:     char    ut_name[8];     /* user id */
   9: #ifdef  UCB_NET
  10:     char    ut_host[16];        /* host name, if remote */
  11: #endif
  12:     long    ut_time;        /* time on */
  13: };

Defined struct's

Usage of this include