Section: Linux System Administration (3)
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login, logout - write utmp and wtmp entries
void login(const struct utmp *ut);
int logout(const char *ut_line);
The utmp file records who is currently using the system.
The wtmp file records all logins and logouts. See
takes the supplied struct utmp
and writes it to both utmp and 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 stdin, stdout, stderr that is a tty, and
stores the corresponding pathname minus a possible leading /dev/
into this field, and then writes the struct to the utmp file.
On the other hand, if no tty 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
argument. 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.
These functions are included in libutil, hence you'll need to add
to your compiler command line.
Note that the
in BSD. Therefore,
is defined as an alias for
user accounting database, configured through _PATH_UTMP in
user accounting log file, configured through _PATH_WTMP in
Not in POSIX.1-2001.
Present on the BSDs.
- GNU DETAILS
- RETURN VALUES
- CONFORMING TO
- SEE ALSO
linux.jgfs.net manual pages