Given the device line,
the logout() function shall search
the user accounting database which is read by getutent()
for an entry with the corresponding line,
and with the type of
If a corresponding entry is located, it shall be updated as follows:
ut_name field shall be set to zeroes
UT_NAMESIZE NUL bytes).
ut_host field shall be set to zeroes
UT_HOSTSIZE NUL bytes).
ut_tv shall be set to the current
time of day.
ut_type field shall be set to
On success, the logout() function shall return non-zero. Zero is returned if there was no entry to remove, or if the utmp file could not be opened or updated.