I've a python script that has to launch a shell command for every file in a dir:
import os
files = os.listdir(".")
for f in files:
os.execlp("myscript", "myscript", f)
This works fine for the first file, but after the "myscript" command has ended, the execution stops and does not come back to the python script.
How can I do? Do I have to fork() before calling os.execlp()?
This question is related to
python
subprocess
popen
os.execl
subprocess: The
subprocessmodule allows you to spawn new processes, connect to their input/output/error pipes, and obtain their return codes.
http://docs.python.org/library/subprocess.html
Usage:
import subprocess
process = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE)
process.wait()
print process.returncode
I use os.system
import os
os.system("pdftoppm -png {} {}".format(path2pdf, os.path.join(tmpdirname, "temp")))
You can use subprocess.Popen. There's a few ways to do it:
import subprocess
cmd = ['/run/myscript', '--arg', 'value']
p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
for line in p.stdout:
print line
p.wait()
print p.returncode
Or, if you don't care what the external program actually does:
cmd = ['/run/myscript', '--arg', 'value']
subprocess.Popen(cmd).wait()
this worked for me fine!
shell_command = "ls -l"
subprocess.call(shell_command.split())
The os.exec*() functions replace the current programm with the new one. When this programm ends so does your process. You probably want os.system().
use spawn
import os
os.spawnlp(os.P_WAIT, 'cp', 'cp', 'index.html', '/dev/null')
You can use subprocess.Popen. There's a few ways to do it:
import subprocess
cmd = ['/run/myscript', '--arg', 'value']
p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
for line in p.stdout:
print line
p.wait()
print p.returncode
Or, if you don't care what the external program actually does:
cmd = ['/run/myscript', '--arg', 'value']
subprocess.Popen(cmd).wait()
this worked for me fine!
shell_command = "ls -l"
subprocess.call(shell_command.split())
The os.exec*() functions replace the current programm with the new one. When this programm ends so does your process. You probably want os.system().
use spawn
import os
os.spawnlp(os.P_WAIT, 'cp', 'cp', 'index.html', '/dev/null')
You can use subprocess.Popen. There's a few ways to do it:
import subprocess
cmd = ['/run/myscript', '--arg', 'value']
p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
for line in p.stdout:
print line
p.wait()
print p.returncode
Or, if you don't care what the external program actually does:
cmd = ['/run/myscript', '--arg', 'value']
subprocess.Popen(cmd).wait()
The os.exec*() functions replace the current programm with the new one. When this programm ends so does your process. You probably want os.system().
You can use subprocess.Popen. There's a few ways to do it:
import subprocess
cmd = ['/run/myscript', '--arg', 'value']
p = subprocess.Popen(cmd, stdout=subprocess.PIPE)
for line in p.stdout:
print line
p.wait()
print p.returncode
Or, if you don't care what the external program actually does:
cmd = ['/run/myscript', '--arg', 'value']
subprocess.Popen(cmd).wait()
I use os.system
import os
os.system("pdftoppm -png {} {}".format(path2pdf, os.path.join(tmpdirname, "temp")))
The os.exec*() functions replace the current programm with the new one. When this programm ends so does your process. You probably want os.system().
The subprocess module has come along way since 2008. In particular check_call and check_output make simple subprocess stuff even easier. The check_* family of functions are nice it that they raise an exception if something goes wrong.
import os
import subprocess
files = os.listdir('.')
for f in files:
subprocess.check_call( [ 'myscript', f ] )
Any output generated by myscript will display as though your process produced the output (technically myscript and your python script share the same stdout). There are a couple of ways to avoid this.
check_call( [ 'myscript', f ], stdout=subprocess.PIPE )myscript produces more that 4k of output). stderr will still be shown unless you add the option stderr=subprocess.PIPE.check_output( [ 'myscript', f ] )check_output returns the stdout as a string so it isnt shown. stderr is still shown unless you add the option stderr=subprocess.STDOUT.use spawn
import os
os.spawnlp(os.P_WAIT, 'cp', 'cp', 'index.html', '/dev/null')
Source: Stackoverflow.com