#!/usr/bin/python
import os
import shutil
import commands
import time
import copy
name = 'test'
echo name
I have a simple python scripts like the above. When I attempt to execute it I get a syntax error when trying to output the name variable.
You cannot use UNIX commands in your Python script as if they were Python code, echo name is causing a syntax error because echo is not a built-in statement or function in Python. Instead, use print name.
To run UNIX commands you will need to create a subprocess that runs the command. The simplest way to do this is using os.system(), but the subprocess module is preferable.
you can also use subprocess module.
import subprocess
proc = subprocess.Popen(['echo', name],
stdin = subprocess.PIPE,
stdout = subprocess.PIPE,
stderr = subprocess.PIPE
)
(out, err) = proc.communicate()
print out
Read: http://www.doughellmann.com/PyMOTW/subprocess/
Related
I am trying to learn to code using python on my own but I ran into a problem.
I am using python's subprocess module to execute a .bat file, but the process seems to get stuck at the bat file. The python code currently looks like this:
import getpass
username = getpass.getuser()
from subprocess import Popen
p = Popen("hidefolder.bat", cwd=r"C:\Users\%s\Desktop" % username)
stdout, stderr = p.communicate()
import sys
sys.exit()
And the .bat file looks like this:
if exist "C:\Users\%username%\Desktop\HiddenFolder\" (
attrib -s -h "HiddenFolder"
rename "HiddenFolder" "Projects"
exit
)
if exist "C:\Users\%username%\Desktop\Projects\" (
rename "Projects" "HiddenFolder"
attrib +s +h "HiddenFolder"
exit
)
if not exist "C:\Users\%username%\Desktop\HiddenFolder\" (
mkdir "C:\Users\%username%\Desktop\HiddenFolder\"
)
exit
Is there a way to kill the child process even if the python script is waiting for the child process to be terminated before continuing? Or is the problem in the child process to start with?
Thank you in advance.
You need to use subprocess.PIPE for stdout and stderr, or else they can't be fetched through Popen.communicate, and is the reason why your process is stuck.
from subprocess import Popen, PIPE
import getpass
username = getpass.getuser()
p = Popen("hidefolder.bat", cwd=r"C:\Users\%s\Desktop" % username, stdout=PIPE, stderr=PIPE)
stdout, stderr = p.communicate()
import sys
sys.exit()
I am a new programmer but i could solve my problem writting below code.
import subprocess
subprocess.call([r'ProcurementSoftwareRun.bat'])
print ('Software run successful')
My bat file was like:
#ECHO OFF
cmd /c start "" "C:\Program Files (x86)\UserName\ERPModule\PROCUREMENT.exe
exit
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$', '.comp.js', src)))
(also see here When using os.execlp, why `python` needs `python` as argv[0])
How about using os.system() like:
os.system('java -jar blabla...')
os.system(command)
Execute the command (a string) in a subshell. This is implemented by calling the Standard C function system(), and has the same limitations. Changes to sys.stdin, etc. are not reflected in the environment of the executed command.
I have a python script that calls a shell scrips, that in turn calls a .exe called iv4_console. I need to print the stdout of iv4_console for debugging purposes. I used this:
Python:
import sys
import subprocess
var="rW015005000000"
proc = subprocess.Popen(["c.sh", var], shell=True, stdout=subprocess.PIPE)
output = ''
for line in iter(proc.stdout.readline, ""):
print line
output += line
Shell:
start_dir=$PWD
release=$1
echo Release inside shell: $release
echo Directory: $start_dir
cd $start_dir
cd ../../iv_system4/ports/visualC12/Debug
echo Debug dir: $PWD
./iv4_console.exe ../embedded/LUA/analysis/verbose-udp-toxml.lua ../../../../../logs/$release/VASP_DUN722_20160307_Krk_Krk_113048_092_1_$release.dvl &>../../../../FCW/ObjectDetectionTest/VASP_DUN722_20160307_Krk_Krk_113048_092_1_$release.xml
./iv4_console.exe ../embedded/LUA/analysis/verbose-udp-toxml.lua ../../../../../logs/$release/VASP_FL140_20170104_C60_Checkout_afterIC_162557_001_$release.dvl &>../../../../FCW/ObjectDetectionTest/VASP_FL140_20170104_C60_Checkout_afterIC_162557_001_$release.xml
exit
But this didn't work, it prints nothing. What do you think?
See my comment, best approach (i.m.o) would be to just use python only.
However, in answer of your question, try:
import sys
import subprocess
var="rW015005000000"
proc = subprocess.Popen(["/bin/bash", "/full/path/to/c.sh"], stdout=subprocess.PIPE)
# Best to always avoid shell=True because of security vulnerabilities.
proc.wait() # To make sure the shell script does not continue running indefinitely in the background
output, errors = proc.communicate()
print(output.decode())
# Since subprocess.communicate() returns a bytes-string, you can use .decode() to print the actual output as a string.
You can use
import subprocess
subprocess.call(['./c.sh'])
to call the shell script in python file
or
import subprocess
import shlex
subprocess.call(shlex.split('./c.sh var'))
I am new to python and working on trying to make a script which checks if a specified host as for example sensu-client exist. I use a deployment software called NSO and run it by: nso status and it shows me this information:
nagios-client host nagios-client down
test host test down
Is there any possibility to make a script to check if for example nagios-Client exist with a script ?
In shell I do it by:
nso status | awk '{ print $1 }'
In this case I would suggest using subprocess' check_output function. The documentation is here. check_output can return, as a string the shell output of a command. So you would have something like this:
import subprocess
foo=subprocess.check_output(['nso', 'status', '|', 'awk', '\'{ print $1 }\''], shell=True)
#Thanks bereal for shell=True
print foo
Of course, if your only targeting linux, you could use the much easier sh module. It allows you to import programs as if they were libraries.
you can use subprocess to run this command and parse the output
import subprocess
command = ['nso', 'status', '|', 'awk', '\'{ print $1 }\'']
p1 = subprocess.Popen(command, stdout=subprocess.PIPE)
You don't have to run awk, since you're already in Python:
import subprocess
proc = subprocess.Popen(['nso', 'status'], stdout=subprocess.PIPE)
# get stdout as a EOL-separated string, ignore stderr for now
out, _ = proc.communicate()
# parse the output, line.split()[0] is awk's $1
items = [line.split()[0] for line in out.split('\n')]
I'm trying to get a few filenames by executing this command in os.popen :
ls /etc/tor/statistiekjes/ |egrep dns
But when I run my script I get :
<open file 'ls /etc/tor/statistiekjes/ |egrep dns', mode 'r' at 0xb7786860>
egrep: write error: Broken pipe
Code :
lscmd = "ls /etc/tor/statistiekjes/ |egrep "+FILE
print lscmd
inputList=os.popen(lscmd,'r')
File is an argument past to the script to grep on
For this particular problem, you could use native Python calls:
import os
import re
for name in (name for name in os.listdir('/etc/tor/statistiekjes/')
if re.search(FILE,name)):
print(repr(name))
However, you are probably looking for a more general solution to calling external programs. In that case, use subprocess instead of os.popen, since os.popen is deprecated:
import subprocess
import shlex
proc1 = subprocess.Popen(shlex.split('ls /etc/tor/statistiekjes/'),
stdout=subprocess.PIPE)
proc2 = subprocess.Popen(shlex.split('egrep {pat}'.format(pat=FILE)),
stdin=proc1.stdout,
stdout=subprocess.PIPE,stderr=subprocess.PIPE)
proc1.stdout.close() # Allow proc1 to receive a SIGPIPE if proc2 exits.
out,err=proc2.communicate()
print(out)
See "Replacing shell pipeline".
PS. subprocess.Popen has a shell=True parameter which could also be used. However, it is best to avoid using shell=True if possible. It is a security risk.
You can use subprocess.Popen, with shell=True flags:
from subprocess import Popen, PIPE
lscmd = "ls /etc/tor/statistiekjes/ |egrep "+FILE
inputList = Popen(lscmd, shell=True, stdout=PIPE).communicate()[0]
print inputList
Enjoy.