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

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

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2017-09-15 GNU