UPDWTMP

Section: Linux Programmer's Manual (3)
Updated: 2017-09-15
Index Return to Main Contents

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NAME

updwtmp, logwtmp - append an entry to the wtmp file  

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);

For logwtmp(), link with -lutil.  

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

 

CONFORMING TO

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 version 2.1):

#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)  

COLOPHON

This page is part of release 4.13 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

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Index

NAME

SYNOPSIS

DESCRIPTION

FILES

ATTRIBUTES

CONFORMING TO

NOTES

SEE ALSO

COLOPHON