1UPDWTMP(3)                 Linux Programmer's Manual                UPDWTMP(3)
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NAME

6       updwtmp, logwtmp - append an entry to the wtmp file
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SYNOPSIS

9       #include <utmp.h>
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11       void updwtmp(const char *wtmp_file, const struct utmp *ut);
12       void logwtmp(const char *line, const char *name, const char *host);
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14       For logwtmp(), link with -lutil.
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DESCRIPTION

17       updwtmp() appends the utmp structure ut to the wtmp file.
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19       logwtmp()  constructs  a utmp structure using line, name, host, current
20       time, and current process ID.  Then it calls updwtmp()  to  append  the
21       structure to the wtmp file.
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FILES

24       /var/log/wtmp
25              database of past user logins
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ATTRIBUTES

28       For  an  explanation  of  the  terms  used  in  this  section,  see at‐
29       tributes(7).
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31       ┌───────────────────────────┬───────────────┬──────────────────────────┐
32       │Interface                  │ Attribute     │ Value                    │
33       ├───────────────────────────┼───────────────┼──────────────────────────┤
34       │updwtmp(), logwtmp()       │ Thread safety │ MT-Unsafe sig:ALRM timer │
35       └───────────────────────────┴───────────────┴──────────────────────────┘
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CONFORMING TO

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

41       For consistency with the other "utmpx"  functions  (see  getutxent(3)),
42       glibc provides (since version 2.1):
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44           #include <utmpx.h>
45           void updwtmpx (const char *wtmpx_file, const struct utmpx *utx);
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47       This  function performs the same task as updwtmp(), but differs in that
48       it takes a utmpx structure as its last argument.
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SEE ALSO

51       getutxent(3), wtmp(5)
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COLOPHON

54       This page is part of release 5.13 of the Linux  man-pages  project.   A
55       description  of  the project, information about reporting bugs, and the
56       latest    version    of    this    page,    can     be     found     at
57       https://www.kernel.org/doc/man-pages/.
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61GNU                               2021-03-22                        UPDWTMP(3)
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