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.
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 setproctitleYou 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.
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.
A few environment variables can be used to customize the module behavior:
SPT_NOENVAvoid clobbering /proc/PID/environ.
On many platforms, setting the process title will clobber the
environ memory area. os.environ will work as
expected from within the Python process, but the content of the file
/proc/PID/environ will be overwritten. If you require this
file not to be broken you can set the SPT_NOENV environment
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_DEBUGPrint 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.
The module can be currently compiled and effectively used on the following platforms:
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.