Python UTMP wrapper for Un*x systems
Project description
Introduction
The pyutmp module provides a Python-oriented interface to the utmp file on Unix-like operating systems. To paraphrase the Linux Programmer’s Manual page utmp(5), the utmp file allows one to discover information about who is currently using (i.e., is logged into) the system. The utmp file is a series of entries whose structure is typically defined by the utmp.h C header file.
This module provides an read-only interface to the underlying operating system’s C utmp API.
Interface and Usage
The pyutmp module supplies two classes: UtmpFile and Utmp. A UtmpFile object represents the open utmp file; when you iterate over a UtmpFile object, it yields successive Utmp objects. For example:
from pyutmp import UtmpFile
import time
for utmp in UtmpFile():
# utmp is a Utmp object
if utmp.ut_user_process:
print '%s logged in at %s on tty %s' % (utmp.ut_user, time.ctime(utmp.ut_time), utmp.ut_line)
UtmpFile
In addition to the __iter__() generator method, allowing iteration over the contents of the utmp file, the UtmpFile class also provides a rewind() method that permits you to reset the file pointer to the top of the file. See the class documentation for details.
Utmp
The fields of the Utmp class are operating system-dependent. However, they will always include at least the following fields:
Field |
Type |
Description |
|---|---|---|
ut_user |
str |
The user associated with the utmp entry, if any. |
ut_line |
str |
The tty or pseudo-tty associated with the entry, if any. In this API, the line will always be the full path to the device. |
ut_host |
str |
The host name associated with the entry, if any. |
ut_time |
timestamp |
The timestamp associated with the entry. This timestamp is in the form returned by time.time() and may be passed directly to methods like time.ctime(). |
ut_user_process |
bool |
Whether or not the utmp entry is a user process (as opposed to a reboot or some other system event). |
On some operating systems, other fields may be present. For instance, on Linux and Solaris systems (and other System V-derived systems), Utmp also contains the following fields:
Optional Field |
Type |
Description |
|---|---|---|
ut_type |
str |
The type of the entry, typically one of the following string values: “RUN_LVL”, “BOOT_TIME”, “NEW_TIME”, “OLD_TIME”, “INIT_PROCESS”, “LOGIN_PROCESS”, “USER_PROCESS”, “DEAD_PROCESS”, “ACCOUNTING”. See the utmp(5) manual page for a description of these values |
ut_pid |
int |
Associated process ID, if any. |
ut_id |
str |
The init(8) ID, or the abbreviated tty name. |
ut_exit_code |
int |
Process exit code, if applicable. |
ut_session |
int |
Session ID, for windowing. |
ut_addr |
int array |
IPv4 address of remote host (if applicable), one octet per array element. |
If you’re writing portable code, you should not count on the presence of those attributes–or, at the very least, you should wrap access to them in a try/catch block that catches AttributeError.
Notes
This module has been tested on the following operating systems:
Ubuntu Linux, version 8.04
FreeBSD
Mac OS X 10.4 (Tiger)
OpenSolaris (2008.05, x86, using the SunStudio 12 compiler suite)
Adding support for other Unix variants should be straightforward.
Restrictions
Access to the utmp file is read-only. There is no provision for writing to the file.
Copyright and License
Copyright (c) 2008 Brian M. Clapper
This is free software, released under the following BSD-like license:
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
The end-user documentation included with the redistribution, if any, must include the following acknowlegement:
This product includes software developed by Brian M. Clapper (bmc@clapper.org, http://www.clapper.org/bmc/). That software is copyright (c) 2008 Brian M. Clapper.
Alternately, this acknowlegement may appear in the software itself, if and wherever such third-party acknowlegements normally appear.
THIS SOFTWARE IS PROVIDED B{AS IS} AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BRIAN M. CLAPPER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
