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How I can execute commands using subprocess function

I want to execute the commands in a python script :
Open cmd as administrator
cd C:\elastic_stack\logstash-7.6.2
.\bin\logstash -f C:/Users/Asus/Desktop/flask_project_part2/project/logstash_file.conf
This what I'm trying to do but it doesn't execute the last config file :
import os, subprocess
from subprocess import *
os.chdir("C:\\Users")
cmd = subprocess.Popen(["runas", "/noprofile", "/user:Administrator", "|", "cd", "C:/elastic_stack/logstash-7.6.2"], shell=True)
cmd.subprocess.run(["./bin/logstash", "-f", "C:/Users/Asus/Desktop/flask_project_part2/project/logstash_file.conf"], shell=True)

You have a combination of forward and backward slashes, but I am assuming that you have installed ELK on a windows machine:
Unfortunately I do not have access to a windows machine, so I didn't get a chance to test the code. But mainly it should be like this:
import os
import subprocess
# desired path
target_dir = os.path.join("C:",os.sep,"elastic_stack",os.sep,"logstash-7.6.2")
# small check
if os.path.isdir(target_dir):
os.chdir(target_dir)
else:
print(" pathname does not refer to an existing directory")
# current working directory
print(os.getcwd())
# start logstash directly os.system will return the return code of the command if it's 0 means OK
os.system(".\\bin\\logstash -f C:\\Users\\Asus\\Desktop\\flask_project_part2\\project\\logstash_file.conf")
# if you need the output after you started logstash it will work ONLY in Python3
process = subprocess.run([".\\bin\\logstash", "-f", "C:\\Users\\Asus\\Desktop\\flask_project_part2\\project\\logstash_file.conf"], stdout=subprocess.PIPE, stderr=subprocess.PIPE)
output = process.stdout
errors = process.stderr
PS:
You can os.sep when constructing absolute or relative paths because in this way the separator is system agnostic.
shell argument default is set to False and it means there is no system shell started up, and if shell=True means system shell will first spin up.

How can I use an executable jar file with a mainClass in python? [duplicate]

I have been looking for an answer for how to execute a java jar file through python and after looking at:
Execute .jar from Python
How can I get my python (version 2.5) script to run a jar file inside a folder instead of from command line?
How to run Python egg files directly without installing them?
I tried to do the following (both my jar and python file are in the same directory):
import os
if __name__ == "__main__":
os.system("java -jar Blender.jar")
and
import subprocess
subprocess.call(['(path)Blender.jar'])
Neither have worked. So, I was thinking that I should use Jython instead, but I think there must a be an easier way to execute jar files through python.
Do you have any idea what I may do wrong? Or, is there any other site that I study more about my problem?

I would use subprocess this way:
import subprocess
subprocess.call(['java', '-jar', 'Blender.jar'])
But, if you have a properly configured /proc/sys/fs/binfmt_misc/jar you should be able to run the jar directly, as you wrote.
So, which is exactly the error you are getting?
Please post somewhere all the output you are getting from the failed execution.

This always works for me:
from subprocess import *
def jarWrapper(*args):
process = Popen(['java', '-jar']+list(args), stdout=PIPE, stderr=PIPE)
ret = []
while process.poll() is None:
line = process.stdout.readline()
if line != '' and line.endswith('\n'):
ret.append(line[:-1])
stdout, stderr = process.communicate()
ret += stdout.split('\n')
if stderr != '':
ret += stderr.split('\n')
ret.remove('')
return ret
args = ['myJarFile.jar', 'arg1', 'arg2', 'argN'] # Any number of args to be passed to the jar file
result = jarWrapper(*args)
print result

I used the following way to execute tika jar to extract the content of a word document. It worked and I got the output also. The command I'm trying to run is "java -jar tika-app-1.24.1.jar -t 42250_EN_Upload.docx"
from subprocess import PIPE, Popen
process = Popen(['java', '-jar', 'tika-app-1.24.1.jar', '-t', '42250_EN_Upload.docx'], stdout=PIPE, stderr=PIPE)
result = process.communicate()
print(result[0].decode('utf-8'))
Here I got result as tuple, hence "result[0]". Also the string was in binary format (b-string). To convert it into normal string we need to decode with 'utf-8'.

With args: concrete example using Closure Compiler (https://developers.google.com/closure/) from python
import os
import re
src = test.js
os.execlp("java", 'blablabla', "-jar", './closure_compiler.jar', '--js', src, '--js_output_file', '{}'.format(re.sub('.js$', '.comp.js', src)))
(also see here When using os.execlp, why `python` needs `python` as argv[0])

How about using os.system() like:
os.system('java -jar blabla...')
os.system(command)
Execute the command (a string) in a subshell. This is implemented by calling the Standard C function system(), and has the same limitations. Changes to sys.stdin, etc. are not reflected in the environment of the executed command.

How can I run a os command without getting output to terminal?

When using subprocess or os libraries, executing the command returns the result in terminal. I want to be able to assign the output to a variable without getting any output returned to the terminal.
pid = subprocess.call(['pidof', process])
pid = os.system('pidof ' + process)
I only want to assign the variable pid, not return text to terminal. I was using the 'commands' library earlier, however it is not supported by python3.

You can try check_output.
import subprocess
output = subprocess.check_output("COMMAND_TO_EXECUTE", shell=True)

Have you tried redirect the command output to DEVNULL?
FNULL = open(os.devnull, 'w')
retcode = subprocess.call(['pidof', process], stdout=FNULL, stderr=subprocess.STDOUT)

python copy file in local network (linux -> linux) and output

I'm trying to write a script to copy files in my RaspberryPi, from my Desktop PC.
Here is my code: (a part)
print "start the copy"
path_pi = '//192.168.2.2:22/home/pi/Stock/'
file_pc = path_file + "/" + file
print "the file to copy is: ", file_pc
shutil.copy2(file_pc, path_pi + file_pi)
Actually I have this error: (in french)
IOError: [Errno 2] Aucun fichier ou dossier de ce type: '//192.168.2.2:22/home/pi/Stock/exemple.txt'
So, how could I proceed? Must I connect the 2 machines before trying to copy?
I have tryed with:
path_pi = r'//192.168.2.2:22/home/pi/Stock'
But the problem is the same. (And file_pc is a variable)
Thanks
Edit:
Ok, I found this:
command = 'scp', file_pc, file_pi
p = subprocess.Popen(command, stdout=subprocess.PIPE)
But no way to have the output... (work with Shell=False)

shutil.copy2() works with local files. 192.168.2.2:22 suggests that you want to copy files over ssh. You could mount the remote directory (RaspberryPi) onto a local directory on your desktop machine (sshfs) so that shutil.copy2() would work.
If you want to see the output of a command then don't set stdout=PIPE (note: if you set stdout=PIPE then you should read from p.stdout otherwise the process may block forever):
from subprocess import check_call
check_call(['scp', file_pc, file_pi])
scp will print to whatever places your parent Python script prints.
To get the output as a string:
from subprocess import check_output
output = check_output(['scp', file_pc, file_pi])
Though It looks like scp doesn't print anything by default if the output is redirected.
You could use pexpect to make scp think that it runs in a terminal:
import pipes
import re
import pexpect # $ pip install pexpect
def progress(locals):
# extract percents
print(int(re.search(br'(\d+)%[^%]*$', locals['child'].after).group(1)))
command = "scp %s %s" % tuple(map(pipes.quote, [file_pc, file_pi]))
status = pexpect.run(command, events={r'\d+%': progress}, withexitstatus=1)[1]
print("Exit status %d" % status)

Do you have SSH enabled? Something like this could help you:
import os
os.system("scp FILE USER#SERVER:PATH")

Run shell command with input redirections from python 2.4?

What I'd like to achieve is the launch of the following shell command:
mysql -h hostAddress -u userName -p userPassword
databaseName < fileName
From within a python 2.4 script with something not unlike:
cmd = ["mysql", "-h", ip, "-u", mysqlUser, dbName, "<", file]
subprocess.call(cmd)
This pukes due to the use of the redirect symbol (I believe) - mysql doesn't receive the input file.
I've also tried:
subprocess.call(cmd, stdin=subprocess.PIPE)
no go there ether
Can someone specify the syntax to make a shell call such that I can feed in a file redirection ?
Thanks in advance.

You have to feed the file into mysql stdin by yourself. This should do it.
import subprocess
...
filename = ...
cmd = ["mysql", "-h", ip, "-u", mysqlUser, dbName]
f = open(filename)
subprocess.call(cmd, stdin=f)

The symbol < has this meaning (i. e. reading a file to stdin) only in shell. In Python you should use either of the following:
1) Read file contents in your process and push it to stdin of the child process:
fd = open(filename, 'rb')
try:
subprocess.call(cmd, stdin=fd)
finally:
fd.close()
2) Read file contents via shell (as you mentioned), but redirect stdin of your process accordingly:
# In file myprocess.py
subprocess.call(cmd, stdin=subprocess.PIPE)
# In shell command line
$ python myprocess.py < filename

As Andrey correctly noticed, the < redirection operator is interpreted by shell. Hence another possible solution:
import os
os.system("mysql -h " + ip + " -u " + mysqlUser + " " + dbName)
It works because os.system passes its argument to the shell.
Note that I assumed that all used variables come from a trusted source, otherwise you need to validate them in order to prevent arbitrary code execution. Also those variables should not contain whitespace (default IFS value) or shell special characters.