Develop Reference

Python script for Network Packet Capture in Nifi

I am new to the nifi platform.
I am trying to use a python script to capture network packet which works on VScode and want to implement same script using NiFi but unable to do so.
This python code I used:
import os, subprocess
from subprocess import PIPE
from datetime import datetime
n = 10
filename = str(datetime.now()).replace(" ","")
b = subprocess.run(f'sudo tcpdump udp -e -i wlp6s0 -nn -vvv -c {n} -w {filename}.raw',shell=True)
c = '"X%02x"'
a = subprocess.run(f"sudo hexdump -v -e '1/1 {c}' {filename}.raw| sed -e 's/\s\+//g' -e 's/X/\\x/g' ", shell=True , stdout=PIPE, stderr=PIPE)
output_file = open (f'{filename}.txt', 'w')
output_file.write(str(a.stdout))
# print("*************************File Created*************************")
output_file.close()
I am using Execute Script Processor for implementing the python script. But it doesn't seem to be working. For executing the "sudo command" I have set to use no password so that no input is needed while executing the script.
Thank you!

Since you're just calling shell commands, you might consider ExecuteStreamCommand instead. You can still run the top-level Python script to call the subprocesses, but since you're not working with flowfile attributes you might be better served being able to call "real" Python. In ExecuteScript the engine is actually Jython and it doesn't let you import native (CPython) modules such as scikit, you can only import pure Python modules (Python scripts that don't themselves import native modules)

Execute Commands in Kali-Linux's Terminal through Python

I want to execute commands in the terminal through a python scripts.
i want to create a script which takes data from a .txt file adds that in a list and then one by one execute them in the terminal.
what i am looking for is a process to execute commands in the terminal in Kali Linux, I couldn't find anything online.
like in windows we use import subprocess or import os
Thank you.
example command is like
python3 app.py

Try this:
import subprocess
command = "python3 app.py"
subprocess.call(command, shell=True)

You can use the os.system function. It returns the return value of the command run.
E.g.,
status = os.system('echo hello')

Open new gnome-terminal and run command

I'm trying to write a script that opens a new terminal then runs a separate python script from that terminal.
I've tried:
os.system("gnome-terminal 'python f.py'")
and
p = Popen("/usr/bin/gnome-terminal", stdin=PIPE)
p.communicate("python f.py")
but both methods only open a new terminal and do not run f.py. How would I go about opening the terminal AND running a separate script?
Edit:
I would like to open a new terminal window because f.py is a simply server that is running serve_forever(). I'd like the original terminal window to stay "free" to run other commands.

Like most terminals, gnome terminal needs options to execute commands:
gnome-terminal [-e, --command=STRING] [-x, --execute]
You probably need to add -x option:
x, --execute
Execute the remainder of the command line inside the terminal.
so:
os.system("gnome-terminal -x python f.py")
That would not run your process in the background unless you add & to your command line BTW.
The communicate attempt would need a newline for your input but should work too, but complex processes like terminals don't "like" being redirected. It seems like using an interactive tool backwards.
And again, that would block until termination. What could work would be to use p.stdin.write("python f.py\n") to give control to the python script. But in that case it's unlikely to work.
So it seems that you don't even need python do to what you want. You just need to run
python f.py &
in a shell.

As of GNOME Terminal 3.24.2 Using VTE version 0.48.4 +GNUTLS -PCRE2
Option “-x” is deprecated and might be removed in a later version of gnome-terminal.
Use “-- ” to terminate the options and put the command line to execute after it.
Thus the preferred syntax appears to be
gnome-terminal -- echo hello
rather than
gnome-terminal -x echo hello

Here is a complete example of how you would call a executable python file with subprocess.call Using argparse to properly parse the input.
the target process will print your given input.
Your python file to be called:
import argparse
parser = argparse.ArgumentParser()
parser.add_argument("--file", help="Just A test", dest='myfile')
args = parser.parse_args()
print args.myfile
Your calling python file:
from subprocess import call
#call(["python","/users/dev/python/sandboxArgParse.py", "--file", "abcd.txt"])
call(["gnome-terminal", "-e", "python /users/dev/python/sandboxArgParse.py --file abcd.txt"])
Just for information:
You probably don't need python calling another python script to run a terminal window with a process, but could do as follows:
gnome-terminal -e "python /yourfile.py -f yourTestfile.txt"

The following code will open a new terminal and execute the process:
process = subprocess.Popen(
"sudo gnome-terminal -x python f.py",
stdout=subprocess.PIPE,
stderr=None,
shell=True
)

I am running a uWS server with this.In my case Popen didn't help(Even though it run the executable, still it couldn't communicate with a client -: socket connection is broken).This is working.Also now they recommends to use "--" instead of "-e".
subprocess.call(['gnome-terminal', "--", "python3", "server_deployment.py"])
#server_deployment.py
def run():
execution_cmd = "./my_executable arg1 arg2 dll_1 dll_2"
os.system(execution_cmd)
run()

Python script ending in SSHing the terminal into a remote server

I am writing a python script which I want to end by SSHing the terminal into a remote machine. I'd read about sub processes, but I don't think these would be appropriate. I would like the user then to interact with the terminal, as if they had typed ssh user#server.path into the terminal.
I am only conserned with it running under Ubuntu.
Thank you

>>> import os
>>> os.execlp('ssh', 'ssh', 'user#server')
or
import subprocess
proc = subprocess.Popen(['ssh', 'user#server'])
result = proc.wait()
print result

how to invoke sshfs within python script?

I want to mount a remote directory using sshfs. sshfs working fine from terminal.
But how to invoke it from within python script?
I tried something like this - but didn't work at all.
import os
cmd = "/usr/bin/sshfs giis#giis.co.in:/home/giis /mnt"
os.system(cmd)

first, you should make sure your sshfs command works fine using the shell. Then, go to here to see many examples of using subprocess module of Python to call your sshfs commmand

import subprocess
mount_command = f'sshfs {host_username}#{host_ip}:{host_data_directory} {local_data_directory}'
subprocess.call(mount_command, shell=True)
# Do your stuff with mounted folder
unmount_command = f'fusermount -u {local_data_directory}'
subprocess.call(unmount_command, shell=True)