NAME

       updwtmp, logwtmp - append an entry to the wtmp file

LIBRARY

       System utilities library (libutil, -lutil)

SYNOPSIS

       #include <utmp.h>

       void updwtmp(const char *wtmp_file, const struct utmp *ut);
       void logwtmp(const char *line, const char *name, const char *host);

DESCRIPTION

       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.

FILES

       /var/log/wtmp
              database of past user logins

ATTRIBUTES

       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 │
       └──────────────────────────────────────────────┴───────────────┴──────────────────────────┘

STANDARDS

       Not in POSIX.1.  Present on Solaris, NetBSD, and perhaps other systems.

NOTES

       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>
           void updwtmpx (const char *wtmpx_file, const struct utmpx *utx);

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

SEE ALSO

       getutxent(3), wtmp(5)