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How to capture bash command output using python script

How to capture bash command output using python script.
For eg:
running below in linux :
[root#xxxxxx oracle]# echo sumit
sumit
[root#xxxxxx oracle]#
How can i re print only the above output using python script ? like running python test.py shoud give 'sumit' as output. i tried below:
test.py :
import sys
sys.stdout.flush()
out = sys.stdin.readline()
print(out)
Above prints only the input i type but not the already displayed output

With subprocess, you can run commands and check their return code, stdout and stderr outputs. Would that help?
For example:
import subprocess as proc
byte_output = proc.check_output(["ls", "-1", "."])
str_output = str(byte_output, "utf-8")
print(str_output)
# prints my local folders dev\ngit

Running a C executable inside a python program

I have written a C code where I have converted one file format to another file format. To run my C code, I have taken one command line argument : filestem.
I executed that code using : ./executable_file filestem > outputfile
Where I have got my desired output inside outputfile
Now I want to take that executable and run within a python code.
I am trying like :
import subprocess
import sys
filestem = sys.argv[1];
subprocess.run(['/home/dev/executable_file', filestem , 'outputfile'])
But it is unable to create the outputfile. I think some thing should be added to solve the > issue. But unable to figure out. Please help.

subprocess.run has optional stdout argument, you might give it file handle, so in your case something like
import subprocess
import sys
filestem = sys.argv[1]
with open('outputfile','wb') as f:
subprocess.run(['/home/dev/executable_file', filestem],stdout=f)
should work. I do not have ability to test it so please run it and write if it does work as intended

You have several options:
NOTE - Tested in CentOS 7, using Python 2.7
1. Try pexpect:
"""Usage: executable_file argument ("ex. stack.py -lh")"""
import pexpect
filestem = sys.argv[1]
# Using ls -lh >> outputfile as an example
cmd = "ls {0} >> outputfile".format(filestem)
command_output, exitstatus = pexpect.run("/usr/bin/bash -c '{0}'".format(cmd), withexitstatus=True)
if exitstatus == 0:
print(command_output)
else:
print("Houston, we've had a problem.")
2. Run subprocess with shell=true (Not recommended):
"""Usage: executable_file argument ("ex. stack.py -lh")"""
import sys
import subprocess
filestem = sys.argv[1]
# Using ls -lh >> outputfile as an example
cmd = "ls {0} >> outputfile".format(filestem)
result = subprocess.check_output(shlex.split(cmd), shell=True) # or subprocess.call(cmd, shell=True)
print(result)
It works, but python.org frowns upon this, due to the chance of a shell injection: see "Security Considerations" in the subprocess documentation.
3. If you must use subprocess, run each command separately and take the SDTOUT of the previous command and pipe it into the STDIN of the next command:
p = subprocess.Popen(cmd, stdin=PIPE, stdout=PIPE)
stdout_data, stderr_data = p.communicate()
p = subprocess.Popen(cmd, stdin=stdout_data, stdout=PIPE)
etc...
Good luck with your code!

Run a command with subprocess that has arguments as with & in Windows

I am trying to run through subprocess a command line command that receives as arguments files. However, these files might have characters like "&" and those can be interpreted as CMD commands if they are not between quotes (").
It usually worked and I had the command passed broken in a list.
Example:
from subprocess import run
file = r'broken&difficult.txt'
command = ['convert', file]
run(command)
However it will return an stdErr:
StdErr: 'diffcult.txt' is not recognized as an internal or external command, operable program or batch file
The returncode is 1.
I have tried to change the file name variable to:
file =r'"broken&difficult.txt"'
The result is that it is not able to find any file. With a returncode of 0

You need to use the CMD escape character - the carrot ^ - before the ampersand.
Try:
import subprocess
file = 'broken^&difficult.txt'
command = ['convert', file]
subprocess.run(command, shell=True)
Example of how this works:
import subprocess
# create a file
with open('broken&difficult.txt', 'w') as fp:
fp.write('hello\nworld')
# use `more` to have OS read contents
subprocess.run(['more', 'broken^&difficult.txt'], shell=True)
# prints:
hello
world
# returns:
CompletedProcess(args=['more', 'broken^&difficult.txt'], returncode=0)

Running PowerShell Script from Python

I'm trying to run a Powershell Script ( check below )
First remark, my Powershell script, when running with Powershell works fine, giving the expected result ( closing all open folders ) , but I have to call this from a Python script, therefore I tried using subprocess.Popen, but I'm having the error :
"io.UnsupportedOperation: fileno"
Tried several different things already, but the solutions suggested aren't working.
I'm trying to call the following Powershell Script :
$shell = New-Object -ComObject Shell.Application
$shell.Windows() | Format-Table LocationName, LocationURL
$window = $shell.Windows()
$window | ForEach-Object { $_.Quit() }
The idea is to close all the open folders, and directly running with Powershell works as expected.
Then I tried to call this script from Python :
p = subprocess.Popen(['powershell.exe', 'C:\\Users\\(correct subfolders)\\TEST.ps1'])
or
p = subprocess.Popen(['C:\\Windows\\System32\\WindowsPowerShell\\v1.0\\powershell.exe', 'C:\\Users\\(correct subfolders)\\TEST.ps1'])
and they don't return errors, a cmd window opens, but nothing happens.
Then I tried the following :
p = subprocess.Popen(['powershell.exe', 'C:\\Users\\(correct subfolders)\\TEST.ps1'], stdout=sys.stdout)
But I have the following error ( check below )
File "<pyshell#15>", line 1, in <module>
p = subprocess.Popen(['powershell.exe', 'C:\\Users\\FernanP\\Desktop\\TEST.ps1'], stdout=sys.stdout)
File "C:\Users\FernanP\AppData\Local\Programs\Python\Python36-32\lib\subprocess.py", line 667, in __init__
errread, errwrite) = self._get_handles(stdin, stdout, stderr)
File "C:\Users\FernanP\AppData\Local\Programs\Python\Python36-32\lib\subprocess.py", line 922, in _get_handles
c2pwrite = msvcrt.get_osfhandle(stdout.fileno())
io.UnsupportedOperation: fileno
I looked into similar Questions here, and people said about the Pillow version, but I'm currently using 6.1.0, so it should not be a problem.
Therefore, either an equivalent to the powershell script directly in Python would be enough, or a way to deal with this issue.
Hope I informed sufficiently.
KR

Here I have created my own function to run any powershell script with its parameters
import subprocess # IMPORT FOR SUB PROCESS . RUN METHOD
POWERSHELL_PATH = "powershell.exe" # POWERSHELL EXE PATH
ps_script_path = "C:\\PowershellScripts\\FTP_UPLOAD.PS1" # YOUR POWERSHELL FILE PATH
class Utility: # SHARED CLASS TO USE IN OUR PROJECT
#staticmethod # STATIC METHOD DEFINITION
def run_ftp_upload_powershell_script(script_path, *params): # SCRIPT PATH = POWERSHELL SCRIPT PATH, PARAM = POWERSHELL SCRIPT PARAMETERS ( IF ANY )
commandline_options = [POWERSHELL_PATH, '-ExecutionPolicy', 'Unrestricted', script_path] # ADD POWERSHELL EXE AND EXECUTION POLICY TO COMMAND VARIABLE
for param in params: # LOOP FOR EACH PARAMETER FROM ARRAY
commandline_options.append("'" + param + "'") # APPEND YOUR FOR POWERSHELL SCRIPT
process_result = subprocess.run(commandline_options, stdout = subprocess.PIPE, stderr = subprocess.PIPE, universal_newlines = True) # CALL PROCESS
print(process_result.returncode) # PRINT RETURN CODE OF PROCESS 0 = SUCCESS, NON-ZERO = FAIL
print(process_result.stdout) # PRINT STANDARD OUTPUT FROM POWERSHELL
print(process_result.stderr) # PRINT STANDARD ERROR FROM POWERSHELL ( IF ANY OTHERWISE ITS NULL|NONE )
if process_result.returncode == 0: # COMPARING RESULT
Message = "Success !"
else:
Message = "Error Occurred !"
return Message # RETURN MESSAGE

You can use subprocess.run and need PIPE and shell. The following code worked for me:
import subprocess
result = subprocess.run([r'C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe', r'C:\Users\(correct subfolders)\TEST.ps1'], stdout=subprocess.PIPE, stderr=subprocess.STDOUT, shell=True)
print(result)
Printing the result can give you the return value like if the command was successfully executed. If you want to extract the result value, you can do,
print(result.stdout.decode('utf-8'))

getting subprocess result in variable

I am executing python script using subprocess.call() in pytho script. The script which gets executed using subproecss is a server process which send result back to calling client.
result = subprocess.call('python -m module/coref_resolution/src/coref/corenlp &', shell = True)
Is there any way to receive result from corenlp.py into result variable?

import shlex
cmd = shlex.split('your command')
output = subprocess.Popen( cmd, stdout = subprocess.PIPE).communicate()[0]