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Description:

proc 1.0

The Python package proc exposes process information available in the Linux
process information pseudo-file system available at /proc. The proc
package is currently tested on cPython 2.7, 3.5+ and PyPy (2.7). The automated
test suite regularly runs on Ubuntu Linux but other Linux variants (also those
not based on Debian Linux) should work fine. For usage instructions please
refer to the documentation.

Installation
Design choices
History
Similar projects
Contact
License

Installation
The proc package is available on PyPI which means installation should be as
simple as:
$ pip install proc
There’s actually a multitude of ways to install Python packages (e.g. the per
user site-packages directory, virtual environments or just installing
system wide) and I have no intention of getting into that discussion here, so
if this intimidates you then read up on your options before returning to these
instructions ;-).
Once you’ve installed the proc package head over to the documentation for
some examples of how the proc package can be used.

Design choices
The proc package was created with the following considerations in mind:

Completely specialized to Linux
It parses /proc and nothing else ;-).

Fully implemented in Python
No binary/compiled components, as opposed to psutil which is way more
portable but requires a compiler for installation.

Very well documented
The documentation should make it easy to get started (as opposed to procfs
which I evaluated and eventually gave up on because I had to resort to reading
through its source code just to be disappointed in its implementation).

Robust implementation
Reading /proc is inherently sensitive to race conditions and the proc
package takes this into account, in fact the test suite contains a test that
creates race conditions in order to verify that they are handled correctly.
The API of the proc package hides race conditions as much as possible and
where this is not possible the consequences are clearly documented.

Layered API design (where each layer is documented)
Builds higher level abstractions on top of lower level abstractions:

The proc.unix module
Defines a simple process class that combines process IDs and common UNIX
signals to implement process control primitives like waiting for a process to
end and gracefully or forcefully terminating a process.

The proc.core module
Builds on top of the proc.unix module to provide a simple, fast and easy
to use API for the process information available in /proc. If you’re
looking for a simple and/or fast interface to /proc that does the heavy
lifting (parsing) for you then this is what you’re looking for.

The proc.tree module
Builds on top of the proc.core module to provide an in-memory tree data
structure that mimics the actual process tree, enabling easy searching and
navigation through the process tree.

The proc.apache module
Builds on top of the proc.tree module to implement an easy to use Python
API that does metrics collection for monitoring of Apache web server worker
memory usage, including support for WSGI process groups.

The proc.cron module
Implements the command line program cron-graceful which gracefully
terminates cron daemons. This module builds on top of the proc.tree
module as a demonstration of the possibilities of the proc package and as a
practical tool that is ready to be used on any Linux system that has Python
and cron installed.

The proc.notify module
Implements the command line program notify-send-headless which can be
used to run the program notify-send in headless environments like cron
jobs and system daemons.

History
I’ve been writing shell and Python scripts that parse /proc for years now
(it seems so temptingly easy when you get started ;-). Sometimes I resorted to
copy/pasting snippets of Python code between personal and work projects because
the code was basically done, just not available in an easy to share form.
Once I started fixing bugs in diverging copies of that code I decided it was
time to combine all of the features I’d grown to appreciate into a single well
tested and well documented Python package with an easy to use API and share it
with the world.
This means that, although I made my first commit on the proc package in March
2015, much of its code has existed for years in various forms.

Similar projects
Below are several other Python libraries that expose process information. If
the proc package isn’t working out for you consider trying one of these. The
summaries are copied and/or paraphrased from the documentation of each
package:

psutil
A cross-platform library for retrieving information on running processes and
system utilization (CPU, memory, disks, network) in Python.

procpy
A Python wrapper for the procps library and a module containing higher level
classes (with some extensions compared to procps).

procfs
Python API for the Linux /proc virtual filesystem.

Contact
The latest version of proc is available on PyPI and GitHub. The
documentation is hosted on Read the Docs and includes a changelog. For bug
reports please create an issue on GitHub. If you have questions, suggestions,
etc. feel free to send me an e-mail at peter@peterodding.com.

License
This software is licensed under the MIT license.
© 2020 Peter Odding.