I need my script to execute a binary file a number of times and get some statistics about its execution time using the the "time" directive. However the following code crashes:
cmd = ["time", "./executable", "<", "input_file"]
result = subprocess.Popen(cmd, stdout = subprocess.PIPE, stderr = subprocess.PIPE)
with the following message:
File "exec_script.py", line 15, in
result = subprocess.Popen("time ./quake < small_input", stdout = subprocess.PIPE, stderr = subprocess.PIPE)
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 have been cracking my skull for hours now and can't figure this out, any help? Note that if I just run that command from the same directory, it works. But not through the script.
Related
windows 7 python 2.7
when I use popen to open a process：
from ctypes import *
dldtool = cdll.LoadLibrary(r'main.dll')
cmd = "dld_tool -c {} -r programmer.bin -f {}".format(port,file)
print cmd
with LOCK:
process = Popen(cmd, stdout=PIPE)
while process.poll() is None:
out = process.stdout.readline()
if out != '':
print out
error occurs：
process = Popen(cmd, stdout=PIPE)
File "C:\Python27\lib\subprocess.py", line 390, in __init__
errread, errwrite)
File "C:\Python27\lib\subprocess.py", line 640, in _execute_child
startupinfo)
WindowsError: [Error 2] The system cannot find the file specified
The main.dll is in the working directory. should I change the code in python or change the any config?
You should use either the shell=True parameter if you want to pass the entire command with arguments as one string:
process = Popen(cmd, stdout=PIPE, shell=True)
or shlex.split to split your command line into a list (after importing shlex):
process = Popen(shlex.split(cmd), stdout=PIPE)
Otherwise the entire command line with arguments would be treated as one file name, and the system naturally would not be able to find it.
How do I write a maven command in python? I saw this example online, but it doesn't seem to be working in Windows.
def local2(command, print_command=False):
from subprocess import Popen, PIPE
p = Popen(command, stdout=PIPE, stderr=PIPE)
if print_command: print " ".join(command)
output, errput = p.communicate()
return p.returncode, output, errput
def uploadQAJavaToNexus():
url = "example"
groupId = "example"
artifactId = "example"
repositoryId = "example"
# filePath =
version = "version"
status, stdout, stderr = local2([
"mvn",
"deploy:deploy-file",
"-Durl=" +url,
"-DrepositoryId=" +repositoryId,
"-Dversion=" + version,
"-Dfile=" + "path"
"-DartifactId=" + artifactId,
"-Dpackaging=" + "jar",
"-DgroupId" + groupId,
])
return status, stdout, stderr
UPDATE: This is the error I'm getting given below:
Traceback (most recent call last):
File "C:\PythonProject\src\Get.py", line 355, in <module>
uploadQAJavaToNexus()
File "C:\Get.py", line 250, in uploadQAJavaToNexus
"-DgroupId" + groupId,
File "C:\Get.py", line 227, in local2
p = Popen(command, stdout=PIPE, stderr=PIPE)
File "C:\Python27\lib\subprocess.py", line 710, in __init__
errread, errwrite)
File "C:\Python27\lib\subprocess.py", line 958, in _execute_child
startupinfo)
WindowsError: [Error 2] The system cannot find the file specified
I prefer to use fabric (http://www.fabfile.org/):
from fabric import local
def maven_start():
local('<cmd>')
$ fab maven_start
I'm trying to collect stderr in memory, instead of directly writing it to a file or stdout. I do this so I can generated the error log file in a certain way. I found a library called StringIO that is an in-memory 'file'. I don't think it does the trick. Here's my code:
buffer = StringIO.StringIO()
status = subprocess.call(args, stdout=log_fps["trace"], stderr=buffer)
if status and self.V_LEVEL:
sys.stderr.write(buffer.getvalue())
print "generated error"
if status:
log_fps["fail"].write("==> Error with files %s and %s\n" % (domain_file, problem_file))
log_fps["fail"].write(buffer.getvalue())
I get the following error:
Traceback (most recent call last):
File "./runit.py", line 284, in <module>
launcher.run_all_cff_domain_examples("ring")
File "./runit.py", line 259, in run_all_cff_domain_examples
result = self.run_clg(in_d["domain"], in_d["problem"], in_d["prefix"])
File "./runit.py", line 123, in run_clg
status = subprocess.call(args, stdout=log_fps["trace"], stderr=buffer)
File "/usr/lib/python2.7/subprocess.py", line 493, in call
return Popen(*popenargs, **kwargs).wait()
File "/usr/lib/python2.7/subprocess.py", line 672, in __init__
errread, errwrite) = self._get_handles(stdin, stdout, stderr)
File "/usr/lib/python2.7/subprocess.py", line 1075, in _get_handles
errwrite = stderr.fileno()
AttributeError: StringIO instance has no attribute 'fileno'
I guess this means that I can't use StringIO to collect stderr in memory. What else can I do, short of writing to a file in /tmp?
stdout = subprocess.check_output(args)
See check_output documentation for more options.
If you don't want to capture stdout, use Popen.communicate:
from subprocess import Popen, PIPE
p = Popen(args, stdout=log_fps["trace"], stderr=PIPE)
_, stderr = p.communicate()
import subprocess
p = subprocess.Popen(args, stdout=log_fps["trace"], stderr=subprocess.PIPE)
_, stderr = p.communicate()
print stderr,
I have the following (simplified) code:
with NamedTemporaryFile() as f:
f.write(zip_data)
f.flush()
subprocess.call("/usr/bin/7z x %s" % f.name)
It dies with the following error:
Traceback (most recent call last):
File "decrypt_resource.py", line 70, in <module>
unpack(sys.argv[2])
File "decrypt_resource.py", line 28, in unpack
print(subprocess.check_output(cmd))
File "/usr/lib/python2.7/subprocess.py", line 568, in check_output
process = Popen(stdout=PIPE, *popenargs, **kwargs)
File "/usr/lib/python2.7/subprocess.py", line 711, in __init__
errread, errwrite)
File "/usr/lib/python2.7/subprocess.py", line 1308, in _execute_child
raise child_exception
OSError: [Errno 2] No such file or directory
However, if I use NamedTemporaryFile(delete=False) and then print & execute the command, it works. What's wrong here?
My System is an ArchLinux with a 3.9.5-1-ARCH kernel.
You are using subprocess.call() incorrectly.
Pass in a list of arguments:
subprocess.call(["/usr/bin/7z", "x", f.name])
The argument is not handled by a shell and is not parsed out like a shell would do. This is a good thing as it prevents a security problem with untrusted command line arguments.
Your other options include using shlex.split() to do the whitespace splitting for you, or, as a last resort, telling subprocess to use a shell for your command with the shell=True flag. See the big warning on the subprocess documentation about enabling the shell.
I'm new to python and I'm trying to make a search bar that searches only 2 directories using two find commands and output the results into an ordered list [].
def search_entry(self, widget,):
s1 = subprocess.Popen(['find /home/bludiescript/tv-shows', '-type f'], shell=False, stdout=subprocess.PIPE)
s2 = subprocess.Popen(['find /media/FreeAgent\ GoFlex\ Drive/tobins-media', '-type f'], stdin=s1.stdout, shell=False, stdout=subprocess.PIPE)
s1.stdout.close()
self.contents = "\n".join(self.list)
s2.communicate(self.contents)
My search bar:
self.search = gtk.Entry()
self.search.connect("activate", self.search_entry,)
self.box1.pack_start(self.search, True, True, 0)
self.search.show()
errormsg:
File "/usr/lib/python2.7/subprocess.py", line 679, in __init__
errread, errwrite)
File "/usr/lib/python2.7/subprocess.py", line 1228, in _execute_child
raise child_exception
OSError: [Errno 2] No such file or directory
Separate all the arguments in the args list:
s1 = subprocess.Popen(['find','/home/bludiescript/tv-shows', '-type','f'], shell=False, stdout=subprocess.PIPE)
s2 = subprocess.Popen(['find','/media/FreeAgent\ GoFlex\ Drive/tobins-media', '-type', 'f'], stdin=s1.stdout, shell=False, stdout=subprocess.PIPE)
OUTPUT on MINE
>>> import subprocess
>>> s1 = subprocess.Popen(['find /home/bludiescript/tv-shows', '-type f'], shell=False, stdout=subprocess.PIPE)
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python2.7/subprocess.py", line 672, in __init__
errread, errwrite)
File "/usr/lib/python2.7/subprocess.py", line 1201, in _execute_child
raise child_exception
OSError: [Errno 2] No such file or directory
>>> s1 = subprocess.Popen(['find','/home/bludiescript/tv-shows', '-type','f'], shell=False, stdout=subprocess.PIPE)
>>> find: `/home/bludiescript/tv-shows': No such file or directory
The first is your original code and it raises the python exception. The second runs correctly but "find" complains because I do not have a "bludiescript/tv-shows" directory on my system.
Did you mean find on line 2? it looks like it is erroring on finding the file "fine"