I have an application which does this: So Python program can start multiple long-lived processes on demand. If I stop main Python program and start again, it knows that sub-program-1.py should be started, because there is a record about status in DB that tells it. So simply it works fine when there is only on…
Tag: subprocess
Why are PATH args to subprocess.run() not portable between Linux and MacOS?
I’m having difficulty with portability between Linux and MacOS with the subprocess.run() method. On Linux, a command like below works just fine as long as someCommand is in my PATH (set in ~/.bashrc). However, on MacOS, the same command does not run, even though someCommand is in my PATH. Instead, I get…
How do I pause other processes when user input / confirmation is required Subprocess Python
If I have a script (process run.py) that will run 3 subprocesses A.py, B.py, C.py (3 scripts called at same time through process run.py). The operation is fine. However say in b.py i have a line such as (pref) How can i get subprocess of A.py and c.py to wait/pause for 5seconds, in order for user to enter y o…
Subprocess – Too many open Files in subprocess
On my system(using python3.6.9) I got the Too many open Files Error. I got the error while executing a subprocess in python. Traceback: I tried to look it up but permanently setting the ulimit didn’t work. I even build a function, that sets the ulimit before executing a subprocess. Answer I didn’t…
Python’s subprocess.Popen() causes strange indentation of output
I have some lines of code that gather NMEA sentences from the gpsmon gpsd command line utility (spawned as a child process) and gathers some internal GPS location data from an external radio. I don’t want the user to see the gpsmon output in the terminal when they run the code, so I redirect it /dev/nul…
Python Subprocess ping -h Returns Exit Status 2
I want to capture ping -h output using Python, it results in exit status 2. I am working on a Linux host. This is the output The command seems to execute normally on the shell. What is the cause of this error? How can I fix it? Answer Following Barmar solution It is a normal behavior for ping, but the
Is there any way to know the command-line options available for a separate program from Python?
I am relatively new to the python’s subprocess and os modules. So, I was able to do the process execution like running bc, cat commands with python and putting the data in stdin and taking the result from stdout. Now I want to first know that a process like cat accepts what flags through python code (If…
subprocess.check_output is too slow on script python but not in interactive python shell
My question is about subprocess. I’m using subprocess to call an external program, I’ve used the check_output() method in which I pass args as list. what I’ve noticed is that when using check_output() from the interactive shell it takes 3 minutes (which is the correct time for executing the …
Why is subprocess ignoring PATH, and how can I change this?
I need to change which program is called by a Python application. Unfortunately I cannot change the Python code. I can only change the calling environment (in particular, PATH). But unfortunately Python’s subprocess module seems to ignore PATH (at least under certain circumstances). How can I force Python to …
Why does the command and its arguments have to be in a list for subprocess.Popen?
I tried doing Which gives me Following Python subprocess.Popen with var/args I did Which did work. Why is that? Why do I have to split my command and its arguments? What’s the rationale behind this design? Python version: Answer That’s how all process invocations work on UNIX. Under the hood, runn…