Feature: Modify `/proc/<pid>/cmdline` only

[dlucredativ]

setproctitle.setproctitle modifies /proc/<pid>/cmdline as well as /proc/<pid>/status. I would like to modify what is seen via ps but retain what e.g. systemctl status shows.

This is what one gets without setproctitle:

user@demo:~$ cat /usr/local/bin/proctitle-demo 
#!/usr/bin/python3

#import setproctitle
import sys

from time import sleep

#setproctitle.setproctitle(' '.join(sys.argv))

while True:
    sleep(1)
user@demo:~$ systemctl status proctitle-demo
● proctitle-demo.service - proctitle-demo
   Loaded: loaded (/etc/systemd/system/proctitle-demo.service; static; vendor preset: enabled)
   Active: active (running) since Fri 2022-11-25 15:30:38 CET; 1min 12s ago
 Main PID: 20802 (proctitle-demo)
    Tasks: 1 (limit: 1149)
   Memory: 2.8M
   CGroup: /system.slice/proctitle-demo.service
           └─20802 /usr/bin/python3 /usr/local/bin/proctitle-demo
user@demo:~$ ps aux | grep 20802 | grep -v grep
63158    20802  0.0  0.8  23040  8544 ?        Ss   15:30   0:00 /usr/bin/python3 /usr/local/bin/proctitle-demo

This is what one gets with setproctitle:

user@demo:~$ sudo vim /usr/local/bin/proctitle-demo
user@demo:~$ cat /usr/local/bin/proctitle-demo 
#!/usr/bin/python3

import setproctitle
import sys

from time import sleep

setproctitle.setproctitle(' '.join(sys.argv))

while True:
    sleep(1)
user@demo:~$ sudo systemctl restart proctitle-demo
user@demo:~$ systemctl status proctitle-demo
● proctitle-demo.service - proctitle-demo
   Loaded: loaded (/etc/systemd/system/proctitle-demo.service; static; vendor preset: enabled)
   Active: active (running) since Fri 2022-11-25 15:32:39 CET; 2s ago
 Main PID: 20879 (/usr/local/bin/)
    Tasks: 1 (limit: 1149)
   Memory: 2.8M
   CGroup: /system.slice/proctitle-demo.service
           └─20879 /usr/local/bin/proctitle-demo
user@demo:~$ ps aux | grep 20879 | grep -v grep
63158    20879  0.0  0.8  25104  8608 ?        Ss   15:32   0:00 /usr/local/bin/proctitle-demo
user@demo:~$ 

The ps output as well as the CGroup tree has been modified as desired, but the Main PID line is unaesthetic.

[dvarrazzo]

I don't personally see a reason to introduce this feature. Would you like to sponsor it, or to propose a merge request?

[dlucredativ]

I might try a merge request some day.