How can I get running process list using Python on Linux?
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7 Answers
IMO looking at the /proc filesystem is less nasty than hacking the text output of ps.
import os
pids = [pid for pid in os.listdir('/proc') if pid.isdigit()]
for pid in pids:
try:
print open(os.path.join('/proc', pid, 'cmdline'), 'rb').read().split('\0')
except IOError: # proc has already terminated
continue
11 Comments
Yanamon
You will have to surround the read() call with a try/except block as a pid returned from reading os.listdir('/proc') may no longer exist by the time you read the cmdline.
bobince
At last! Validation! Now I can stop! :-)
Good Person
-1 for /proc since its not portable and there are better interfaces available
Federico
Watch out: the command line is terminated by 0x00. Whitespaces are also replaced with the same character.
RichVel
Just use
psutil - it does all this through a nice Pythonic interface and is portable if you ever want to run on a non-Linux server. |
You could use psutil as a platform independent solution!
import psutil
psutil.pids()
[1, 2, 3, 4, 5, 6, 7, 46, 48, 50, 51, 178, 182, 222, 223, 224,
268, 1215, 1216, 1220, 1221, 1243, 1244, 1301, 1601, 2237, 2355,
2637, 2774, 3932, 4176, 4177, 4185, 4187, 4189, 4225, 4243, 4245,
4263, 4282, 4306, 4311, 4312, 4313, 4314, 4337, 4339, 4357, 4358,
4363, 4383, 4395, 4408, 4433, 4443, 4445, 4446, 5167, 5234, 5235,
5252, 5318, 5424, 5644, 6987, 7054, 7055, 7071]
8 Comments
enthus1ast
just take a look at the documentation.
amos
It's not completely platform independent -- on OSX you can run into AccessDenied errors: groups.google.com/forum/?fromgroups=#!topic/psutil/bsjpawhiWms
JSmyth
@amos kinda makes sense - you'd want to have privileges in place first before reaching out to information about processes. Thanks for the hint.
RichVel
To amplify the OSX point - you need root privileges on OSX to get process info, unlike Linux.
BartBiczBoży
And it is available as python-psutil from epel for fedora/centos/rhel family.
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The sanctioned way of creating and using child processes is through the subprocess module.
import subprocess
pl = subprocess.Popen(['ps', '-U', '0'], stdout=subprocess.PIPE).communicate()[0]
print pl
The command is broken down into a python list of arguments so that it does not need to be run in a shell (By default the subprocess.Popen does not use any kind of a shell environment it just execs it). Because of this we cant simply supply 'ps -U 0' to Popen.
Comments
You can use a third party library, such as PSI:
PSI is a Python package providing real-time access to processes and other miscellaneous system information such as architecture, boottime and filesystems. It has a pythonic API which is consistent accross all supported platforms but also exposes platform-specific details where desirable.
1 Comment
RichVel
PSI was last updated in 2009, whereas psutil was updated this month (Nov 2015) - seems like psutil is a better bet.
I would use the subprocess module to execute the command ps with appropriate options. By adding options you can modify which processes you see. Lot's of examples on subprocess on SO. This question answers how to parse the output of ps for example:)
You can, as one of the example answers showed also use the PSI module to access system information (such as the process table in this example).
Comments
from psutil import process_iter
from termcolor import colored
names = []
ids = []
x = 0
z = 0
k = 0
for proc in process_iter():
name = proc.name()
y = len(name)
if y>x:
x = y
if y<x:
k = y
id = proc.pid
names.insert(z, name)
ids.insert(z, id)
z += 1
print(colored("Process Name", 'yellow'), (x-k-5)*" ", colored("Process Id", 'magenta'))
for b in range(len(names)-1):
z = x
print(colored(names[b], 'cyan'),(x-len(names[b]))*" ",colored(ids[b], 'white'))
2 Comments
Ruli
Welcome to StackOverflow. While this code may solve the question, including an explanation of how and why this solves the problem would really help to improve the quality of your post, and probably result in more up-votes. Remember that you are answering the question for readers in the future, not just the person asking now. Please edit your answer to add explanations and give an indication of what limitations and assumptions apply.
Brandon
This code is poorly written, needlessly complex, and unpythonic. It is not a good example of how to achieve this.
import os
lst = os.popen('sudo netstat -tulpn').read()
lst = lst.split('\n')
for i in range(2,len(lst)):
print(lst[i])
