syntax error near unexpected token while use subprocess

Question

This design makes me cry,code below,please help

def runbatch(CMD,HOST):
    print CMD
    print HOST
    for host in HOST:
        env.host_string=host
        print CMD
        print env.host_string
        print "Execute command : \"%s\" at Host : %s" %(CMD,host)
        print "-------------------------------------------------"
        p=subprocess.Popen("run('ls')",shell=True,
            stderr=subprocess.PIPE,
            stdin=subprocess.PIPE)
        output = p.communicate()
        print output

error shows

(None, "/bin/sh: -c: line 0: syntax error near unexpected token 'ls''\\n/bin/sh: -c: line 0: run('ls')'\\n")

Answer 1

subprocess.Popen() runs a bash command on your local machine . What fabric has to offer is a way to enter a command on local machine which got sent to and run on a remote machine . To this end, you need a fabfile.py (for now, you need to name it precisely fabfile.py ) where you store the fabric fabric.api.run() command, which actually is a Python command and not a bash command. The argument of fabric.api.run() is a bash command that runs on the remote machine . Eg of a fabfile.py

from fabric.api import run
from fabric.api import env
def runcommand():
    run(env.my_command)

Using this example, you could activate this remote call by using command line fab --set my_command=some_bash_command -H remote_host_ip runcommand . This string is the string you should pass to subprocess.Popen() in your script. Eg let's call your script stackoverflow.py that takes in a command line argument the bash function to be executed on the remote machine

import subprocess
import sys

p=subprocess.Popen("fab --set my_command="+sys.argv[1]+" -H localhost runcommand",shell=True,
                    stderr=subprocess.PIPE,
                    stdin=subprocess.PIPE)
output = p.communicate()
print output

Sample run:

Chip chip@ 12:10:58@ ~: python stackoverflow.py ls
[localhost] Executing task 'runcommand'
[localhost] run: ls
[localhost] out: AllArms.py             fines
[localhost] out: Applications               github
[localhost] out: Box Sync               grades_assgn1
[localhost] out: DFExperiment               heuristic.py
[localhost] out: Desktop                    honour-project-in-thompson-sampling
[localhost] out: Documents              jags_bin
[localhost] out: Downloads              latemath
[localhost] out: Dropbox                    launchall.sh
[localhost] out: FIT3080                    launcher
[localhost] out: GaussianExperiments            launchucb.sh
[localhost] out: GoogleDrive                minuteSep5
[localhost] out: HierarchicalStan.py            minutes22aug
[localhost] out: IMG_6169.JPG               model1.pkl
[localhost] out: Library                    mydata
[localhost] out: Monarch                    notes15Aug2016
[localhost] out: Movies                 notesSep12
[localhost] out: Music                  old-honour
[localhost] out: PTSTuneBeta                oracle.R
[localhost] out: Pictures               paper
[localhost] out: Public                 parallelExperiments
[localhost] out: Samsung                    people_to_mark_first
[localhost] out: WindowFrame.class          rezaPhone
[localhost] out: WindowFrame.java           spike.py
[localhost] out: a.out                  stackoverflow.class
[localhost] out: aaai.tar.gz                stackoverflow.cpp
[localhost] out: all_experiments                stackoverflow.java
[localhost] out: api4.csv               stackoverflow.py
[localhost] out: atlas                  test
[localhost] out: boostlib               test.py
[localhost] out: codes_and_data.tar.gz          test.txt
[localhost] out: eclipse                    test1.html
[localhost] out: emo                    test2.html
[localhost] out: experimentlist             testlib.py
[localhost] out: fabfile.py             testlib.pyc
[localhost] out: fabfile.pyc                uselib.py
[localhost] out: file1                  uselib.pyc
[localhost] out: file2
[localhost] out: 


Done.
Disconnecting from localhost... done.
(None, "[localhost] Login password for 'hiennguyen': \n")

IMPORTANT NOTE : When calling fab this way, you might have to:

1. Enable ssh access to your remote machine . In this case, the remote machine is just localhost

2. Sometimes, the remote host requires you to enter password and you will not be prompted to enter password (this is the case on my machine). If you wait for awhile and see nothing, you might want to enter the password then hit ENTER.