updwtmp, logwtmp - append an entry to the wtmp file

       For an explanation of the terms used in this section, see attributes(7).
       ┌────────────────────────────────────────────────────────────┬───────────────┬──────────────────────────┐
       │ Interface                                                  │ Attribute     │ Value                    │
       ├────────────────────────────────────────────────────────────┼───────────────┼──────────────────────────┤
       │ updwtmp(), logwtmp()                                       │ Thread safety │ MT-Unsafe sig:ALRM timer │
       └────────────────────────────────────────────────────────────┴───────────────┴──────────────────────────┘

updwtmp() appends the utmp structure ut to the wtmp file.

       logwtmp() constructs a utmp structure using line, name, host, current time, and current process ID.  Then
       it calls updwtmp() to append the structure to the wtmp file.

/var/log/wtmp
              database of past user logins

       Solaris, NetBSD.

       System utilities library (libutil, -lutil)

       updwtmp, logwtmp - append an entry to the wtmp file

getutxent(3), wtmp(5)

Linux man-pages 6.9.1                              2024-05-02                                         updwtmp(3)

       None.

#include<utmp.h>voidupdwtmp(constchar*wtmp_file,conststructutmp*ut);voidlogwtmp(constchar*line,constchar*name,constchar*host);

       For consistency with the other "utmpx" functions (see getutxent(3)), glibc provides (since glibc 2.1):

           #define_GNU_SOURCE          /* See feature_test_macros(7) */
           #include<utmpx.h>voidupdwtmpx(constchar*wtmpx_file,conststructutmpx*utx);

       This  function performs the same task as updwtmp(), but differs in that it takes a utmpx structure as its
       last argument.