A Python module to customize the process title
| author: | Daniele Varrazzo |
|---|
The setproctitle module allows a process to change its title (as displayed
by system tools such as ps, top or MacOS Activity Monitor).
Changing the title is mostly useful in multi-process systems, for example when a master process is forked: changing the children's title allows to identify the task each process is busy with. The technique is used by PostgreSQL and the OpenSSH Server for example.
The procedure is hardly portable across different systems. PostgreSQL provides a good multi-platform implementation: this package was born as a wrapper around PostgreSQL code.
Installation
setproctitle is a C extension: in order to build it you will need a C
compiler and the Python development support (the python-dev or
python3-dev package in most Linux distributions). No further external
dependencies are required.
You can use pip to install the module:
pip install setproctitle
You can use pip -t or virtualenv for local installations, sudo pip
for a system-wide one... the usual stuff. Read pip or virtualenv docs for
all the details.
Usage
Note
You should import and use the module (even just calling getproctitle())
pretty early in your program lifetime: code writing env vars may
interfere with the module initialisation.
The setproctitle module exports the following functions:
setproctitle(title)- Set title as the title for the current process.
getproctitle()- Return the current process title.
The process title is usually visible in files such as /proc/PID/cmdline,
/proc/PID/status, /proc/PID/comm, depending on the operating system
and kernel version. These information are used by user-space tools such as
ps and top.
setthreadtitle(title)- Set title as the title for the current thread.
getthreadtitle()- Get the current thread title.
The thread title is exposed by some operating systems as the file
/proc/PID/task/TID/comm, which is used by certain tools such as htop.
Environment variables
A few environment variables can be used to customize the module behavior:
SPT_NOENV-
Avoid clobbering
/proc/PID/environ.On many platforms, setting the process title will clobber the
environmemory area.os.environwill work as expected from within the Python process, but the content of the file/proc/PID/environwill be overwritten. If you require this file not to be broken you can set theSPT_NOENVenvironment variable to any non-empty value: in this case the maximum length for the title will be limited to the length of the command line. SPT_DEBUG-
Print debug information on
stderr.If the module doesn't work as expected you can set this variable to a non-empty value to generate information useful for debugging. Note that the most useful information is printed when the module is imported, not when the functions are called.
Module status
The module can be currently compiled and effectively used on the following platforms:
- GNU/Linux
- BSD
- MacOS X
- Windows
Note that on Windows there is no way to change the process string:
what the module does is to create a Named Object whose value can be read
using a tool such as Process Explorer (contribution of a more useful tool
to be used together with setproctitle would be well accepted).
The module can probably work on HP-UX, but I haven't found any to test with. It is unlikely that it can work on Solaris instead.
