Section: Linux Programmer's Manual (3)
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login, logout - write utmp and wtmp entries
void login(const struct utmp *ut);
int logout(const char *ut_line);
Link with -lutil.
The utmp file records who is currently using the system.
The wtmp file records all logins and logouts.
takes the supplied
and writes it to both the utmp and the wtmp file.
clears the entry in the utmp file again.
takes the argument
struct, fills the field
(if there is such a field) with the value
and fills the field
(if there is such a field) with the process ID of the calling process.
Then it tries to fill the field
It takes the first of
that is a terminal, and
stores the corresponding pathname minus a possible leading
into this field, and then writes the struct to the utmp file.
On the other hand,
if no terminal name was found, this field is filled with "???"
and the struct is not written to the utmp file.
After this, the struct is written to the wtmp file.
function searches the utmp file for an entry matching the
If a record is found, it is updated by zeroing out the
fields, updating the
timestamp field and setting
(if there is such a field) to
function returns 1 if the entry was successfully written to the
database, or 0 if an error occurred.
user accounting database, configured through
user accounting log file, configured through
For an explanation of the terms used in this section, see
In the above table,
signifies that if any of the functions
are used in parallel in different threads of a program,
then data races could occur.
calls those functions,
so we use race:utent to remind users.
Not in POSIX.1.
Present on the BSDs.
Note that the
is defined as an alias for
This page is part of release 4.15 of the Linux
A description of the project,
information about reporting bugs,
and the latest version of this page,
can be found at
- GNU details
- RETURN VALUE
- CONFORMING TO
- SEE ALSO
This document was created by
using the manual pages.
Time: 04:50:02 GMT, September 25, 2018