Getting List of Running processes and applications

Solution 1:

Generally ps command does it.

If you type man ps, you will get the manual for this command, and there you can check which flag you will need. For example, ps -e will list all running processes in the system.

Another command is top which will show an active view of all running process.

Solution 2:

The following script lists all processes, and splits them in applications and other processes.

As definition for an application, I practice that the process is initiated from a .desktop file (since practically all applications are represented by a .desktop file), and that the .desktop file appears in Dash (the .desktop file has no line: NoDisplay=true).

Work to be done:

The script, as it is, derives the application's process name from the (last section of-) the command, found in the desktop file, and also from information, found in the possible symlinks it might refer to (e.g. in case of LibreOffice > process name: soffice.bin). In some cases however, an application runs from a remote script, called from the .desktop file. In those cases, the process will not be recognized as an application.

The script gives an output like:

Processes, related to applications:
  PID TTY          TIME CMD
 1933 ?        00:03:55 firefox
18091 ?        00:00:00 dia
18162 ?        00:00:01 soffice.bin
31167 ?        00:00:06 alarm-clock-app
31174 ?        00:00:09 nautilus
31301 ?        00:00:20 dropbox
31998 ?        00:01:35 idle3

Other processes:
  PID TTY          TIME CMD
    1 ?        00:00:01 init
    2 ?        00:00:00 kthreadd
    3 ?        00:00:02 ksoftirqd/0
    5 ?        00:00:00 kworker/0:0H
    7 ?        00:00:15 rcu_sched
    8 ?        00:00:08 rcuos/0

etc...

The script

#!/usr/bin/env python3

import os
import subprocess

def createlist_appcommands():
    dtfile_dir = "/usr/share/applications"
    dtfile_list = [item for item in os.listdir(dtfile_dir) if item.endswith(".desktop")]
    commands = []
    for item in dtfile_list:
        try:
            with open(dtfile_dir+"/"+item) as data:
                searchlines = data.readlines()
                command = [line for line in searchlines if line.startswith("Exec=")
                           and not "NoDisplay=true\n" in searchlines
                            ][0].replace("Exec=", "").replace("\n", "").split("/")[-1].split(" ")[0]
            commands.append(command)
        except Exception:
            pass
    return commands + [trace_symlinks(item) for item in commands if not trace_symlinks(item)== None]

def trace_symlinks(command):
    target = subprocess.Popen(["which", command], stdout=subprocess.PIPE)
    location = (target.communicate()[0].decode("utf-8")).split("\n")[0]                                                          
    check_filetype = subprocess.Popen(["file", location], stdout=subprocess.PIPE)
    filetype = (check_filetype.communicate()[0].decode("utf-8")).split("\n")[0]
    if "symbolic link" in filetype:
        return filetype.split("/")[-1].replace("' ", "")
    else:
        pass

def createlist_runningprocs():
    processesb = subprocess.Popen(["ps", "-e"], stdout=subprocess.PIPE)
    process_listb = (processesb.communicate()[0].decode("utf-8")).split("\n")
    linked_commands = [(item, item[24:]) for item in process_listb][1:]
    applist = createlist_appcommands()
    print("Processes, related to applications:\n  PID TTY"+" "*10+"TIME CMD")
    matches = []
    for item in applist:
        for i in range(0, len(linked_commands)):
            if item[:15] in linked_commands[i][1] and len(item[:15])/len(linked_commands[i][1]) > 0.5:
                matches.append(i)
    matches = sorted(matches)
    for i in range(0, len(linked_commands)):
        if i in matches:
            print(linked_commands[i][0])
    print("\nOther processes:\n  PID TTY"+" "*10+"TIME CMD")
    for i in range(0, len(linked_commands)):
        if not i in matches:
            print(linked_commands[i][0])

createlist_runningprocs()

How to use

Copy the script in an empty file, save it as processes.py, run it by the command:

python3 /path/to/processes.py

Edit: updated my answer, rewrote the script.

Improvements:

• (much) better performance

• the script now traces and recognizes applications, initiated via symlinks (which may have another process name). Although exceptions are always possible, they should be rare now.