I am trying to execute a program with python using subprocess
The format our professor gave us was subprocess(path/executableProgram)
File: OS377.py
I am doing it as subprocess(['/home/Joseph/OS377.py']) but I am getting errors
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python3.2/subprocess.py", line 471, in call
return Popen(*popenargs, **kwargs).wait()
File "/usr/lib/python3.2/subprocess.py", line 745, in __init__
restore_signals, start_new_session)
File "/usr/lib/python3.2/subprocess.py", line 1361, in _execute_child
raise child_exception_type(errno_num, err_msg)
OSError: [Errno 8] Exec format error
I need to execute a file using this format but am unsure how to go about it
Code:
def RUN(file):
pid = os.fork() #pid is non-zero in the parent process and 0 in the child
if pid: #parent
os.waitpid(pid,0)
elif pid == 0: #child
print("path is : ")
child(file)
def child(file):
#path = os.path.abspath(file)
#print(path)
subprocess.call(os.path.abspath('OS377.py'))
subprocess.call(['python', os.path.abspath('OS377.py')].
The file you're calling, a python script, may not be marked as executable (chmod u+x file.py). Alternatively, you should probably be executing it with $ python file.py - which is calling the python interpreter and passing it the name of your script as the first argument. So you should put it as subprocess.call(['python', '/home/Joe/file.py'].
Btw, did you mean subprocess.call() instead of just subprocess()?
Related
In my program I call the command:
command_two = 'sfit4Layer0.py -bv5 -fs'
subprocess.call(command_two.split(), shell=False)
I am using PyCharm and I get the error message:
Traceback (most recent call last):
File "part2test.py", line 5, in <module>
subprocess.call(command_two.split(), shell=False) #writes the summary file
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 522, in call
return Popen(*popenargs, **kwargs).wait()
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 710, in __init__
errread, errwrite)
File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/subprocess.py", line 1335, in _execute_child
raise child_exception
OSError: [Errno 2] No such file or directory
When walking through my program, it never gets to the program I want it to sfit4Layer0.py, it is getting stuck in subprocess but I am not sure why. Changing the shell=True doesn't do anything helpful either - I don't get these error messages but it does not execute my code properly. Any suggestions would be helpful.
My bash profile:
PATH="~/bin:/usr/bin:${PATH}"
export PATH PYTHONPATH="/Users/nataliekille/Documents/sfit4/pbin/Layer0:/Users/nataliekille/Documents/sfit4/pbin/Layer1:/Users/nataliekille/Documents/sfit4/pbin/ModLib:/Users/nataliekille/Documents/sfit4/SpectralDB"
export PYTHONPATH
PATH=${PATH}:${PYTHONPATH}
export PATH
You've missed an important part of the subprocess documentation. "If passing a single string [at the command, rather than a list of strings], either shell must be True (see below) or else the string must simply name the program to be executed without specifying any arguments."
So the kernel is compaining because there is not executable with the name 'sfit4Layer0.py -bv5 -fs'. Should work if you replace the string with (for example) 'sfit4Layer0.py -bv5 -fs'.split(), or ['sfit4Layer0.py', '-bv5', '-fs'].
So, I made a command called jel, which is executable as jel. It is run in Python, and when I run jel doctor, in jel.py it gives me a error(the main file). The code looks like this: Note that all necessary modules are already imported.
elif arg == 'doctor':
subprocess.call(['cd', 'js'])
ver = subprocess.call(['node', 'version.js'])
subprocess.call(['cd', '..'])
if not ver == version:
print 'jel doctor: \033[91found that version\033[0m ' + str(version) + ' \033[91mis not the current version\033[0m'
print 'jel doctor: \033[92mrun jel update\033[0m'
sys.exit()
The js file version.js is run on node, and looks like this: All necessary packages are installed
var latest = require('latest');
latest('jel', function(err, v) {
console.log(v);
// => "0.0.3"
if (err) {
console.log('An error occurred.');
}
});
It is giving me this error when the jel.py file uses subprocess to call cs js and node version.js:
Traceback (most recent call last):
File "/bin/jel", line 90, in <module>
subprocess.call(['cd', 'js'])
File "/usr/lib/python2.7/subprocess.py", line 522, in call
return Popen(*popenargs, **kwargs).wait()
File "/usr/lib/python2.7/subprocess.py", line 710, in __init__
errread, errwrite)
File "/usr/lib/python2.7/subprocess.py", line 1327, in _execute_child
raise child_exception
OSError: [Errno 2] No such file or directory
bjskistad:~/workspace (master) $ jel doctor
Traceback (most recent call last):
File "/bin/jel", line 90, in <module>
subprocess.call(['cd', 'js'])
File "/usr/lib/python2.7/subprocess.py", line 522, in call
return Popen(*popenargs, **kwargs).wait()
File "/usr/lib/python2.7/subprocess.py", line 710, in __init__
errread, errwrite)
File "/usr/lib/python2.7/subprocess.py", line 1327, in _execute_child
raise child_exception
OSError: [Errno 2] No such file or directory
I believe it is saying the directory doesn't exist, although it does. Do I need to call something else before?
There are at least three problems with your code snippet:
cd is a shell built-in, not an executable program. If you want to invoke cd, you'll need to invoke the shell.
The cd command only affects the shell in which it runs. It will have no effect upon the python program, or any subsequent subprocesses.
The return code from subprocess.call() is not the text that the program wrote to stdout. To get that text, try subprocess.check_output().
Try this:
#UNTESTED
elif arg == 'doctor':
ver = subprocess.check_output(['cd js && node version.js'], shell=True)
if not ver == version:
As already pointed out changing the directory is only reflected in the subprocess. You should use os.chdir to change your working directory but another alternative is to specify the cwd to subprocess which avoids any need to cd or os.chdir:
version = subprocess.check_output(['node', 'version.js'], cwd="js")
You should also use != in your if and you probably want to rstrip the newline:
if version != ver.rstrip():
When I try to shell out of my Python 3.51 program to run the Popen command I get the following errors. Yet when I copy the exact string I'm passing to Popen to the Terminal command line it works fine and opens the file in Adobe Reader which is my default app for the .pdf files.
Here is the Code:
finalCall = r'open /Users/gbarnabic/Documents/1111/combined.pdf'
print(finalCall)
pid_id = subprocess.Popen(finalCall).pid
Here is the error:
open /Users/gbarnabic/Documents/1111/combined.pdf
Exception in Tkinter callback
Traceback (most recent call last):
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/tkinter/init.py", line 1549, in call
return self.func(*args)
File "pdfcomb2.py", line 212, in change_dir
self.openPDF(outFileName, pageNum)
File "pdfcomb2.py", line 426, in openPDF
subprocess.run(finalCall)
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/subprocess.py", line 696, in run
with Popen(*popenargs, **kwargs) as process:
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/subprocess.py", line 950, in init
restore_signals, start_new_session)
File "/Library/Frameworks/Python.framework/Versions/3.5/lib/python3.5/subprocess.py", line 1544, in _execute_child
raise child_exception_type(errno_num, err_msg)
FileNotFoundError: [Errno 2] No such file or directory: 'open /Users/gb/Documents/1111/combined.pdf'
Georges-MBP:filepicktest gb$ open /Users/gb/Documents/1111/combined.pdf
Georges-MBP:filepicktest gb$
With Popen you need to set shell=True to pass command as a string or split command in a list of arguments. Could be done with shlex
import shlex
import subprocess
subprocess.Popen(shlex.split('open ....'))
You could check example in documentation:
https://docs.python.org/2/library/subprocess.html#subprocess.Popen
So the error here means that Python try to run file with name open /Users/gb/Documents/1111/combined.pdf. Obviously it doesn't exist
I'm having issues with Python finding an available Executable on my Linux machine. My default PATH includes this Executable (svnlook) but when I run the python script the below function fails to find executable. Any ideas on how to fix this?
def command_output(cmd):
child = subprocess.Popen(cmd.split(), stdout=subprocess.PIPE)
output = child.communicate()[0]
return output, child.returncode
def get_author():
cmd = "svnlook author %s %s %s" % (svn_opt, svn_txn, svn_repo)
author, return_code = command_output(cmd)
return author.strip()
Error:
Traceback (most recent call last):
File "/home/user/app/csvn/data/repositories/repo/hooks/pre-commit", line 82, in <module>
author = get_author()
File "/home/user/app/csvn/data/repositories/repo/hooks/pre-commit", line 53, in get_author
author, return_code = command_output(cmd)
File "/home/user/app/csvn/data/repositories/repo/hooks/pre-commit", line 36, in command_output
child = subprocess.Popen(cmd.split(), stdout=subprocess.PIPE)
File "/home/user/app/activepython-2.7.2.5_x86_64/lib/python2.7/subprocess.py", line 679, in __init__
errread, errwrite)
File "/home/user/app/activepython-2.7.2.5_x86_64/lib/python2.7/subprocess.py", line 1228, in _execute_child
raise child_exception
OSError: [Errno 2] No such file or directory
Error: [Errno 2] No such file or directory
You probably want to provide the full path to the executable, e.g. /usr/bin/svnlook or /usr/local/bin/svnlook instead of just svnlook.
See this answer to a related question for details.
Try running it from the console. Make sure the permissions/executability is correct. Try os.system().
how can I open an java file in python?, i've search over the net and found this:
import os.path, subprocess
from subprocess import STDOUT, PIPE
def compile_java (java_file):
subprocess.check_call(['javac', java_file])
def execute_java (java_file):
cmd=['java', java_file]
proc=subprocess.Popen(cmd, stdout = PIPE, stderr = STDOUT)
input = subprocess.Popen(cmd, stdin = PIPE)
print(proc.stdout.read())
compile_java("CsMain.java")
execute_java("CsMain")
but then I got this error:
Traceback (most recent call last):
File "C:\Python33\lib\subprocess.py", line 1106, in _execute_child
startupinfo)
FileNotFoundError: [WinError 2] The system cannot find the file specified
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "C:\casestudy\opener.py", line 13, in <module>
compile_java("CsMain.java")
File "C:\casestudy\opener.py", line 5, in compile_java
subprocess.check_call(['javac', java_file])
File "C:\Python33\lib\subprocess.py", line 539, in check_call
retcode = call(*popenargs, **kwargs)
File "C:\Python33\lib\subprocess.py", line 520, in call
with Popen(*popenargs, **kwargs) as p:
File "C:\Python33\lib\subprocess.py", line 820, in __init__
restore_signals, start_new_session)
File "C:\Python33\lib\subprocess.py", line 1112, in _execute_child
raise WindowsError(*e.args)
FileNotFoundError: [WinError 2] The system cannot find the file specified
>>>
the python file and java file is in the same folder, and I am using Python 3.3.2, how can I resolve this? or do you guys have another way on doing this?, any answer is appreciated thanks!
I think it isn't recognizing the javac command. Try manually running the command and if javac isn't a recognized command, register it in your PATH variable and try again.
Or you could just try typing the full pathname to the Java directory for javac and java.
you need to add path to your java file name. like this:
compile_java("C:\\path\to\this\CsMain.java")