rosshellX.py

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#!/usr/bin/env python
import sys
import os
import subprocess as sp
import fcntl

import roslib; roslib.load_manifest("rosshell")
import rospy
from std_msgs.msg import String

import time

def callbackStdIn(msg):
        global process
        
        # un/comment this to enable tostopic to publish strings...
        msg.data = msg.data.replace("\\n", "\n")
        
        process.stdin.write(msg.data)
        rospy.loginfo("stdin: " +msg.data)

if __name__ == "__main__":

        rospy.init_node('rosshellX')
        
        topicStdOut = rospy.get_param('~stdout', "/rosshellX/stdout")
        topicStdErr = rospy.get_param('~stderr', "/rosshellX/stderr")
        topicStdIn  = rospy.get_param('~stdin', "/rosshellX/stdin")
        cmd_user    = rospy.get_param('~command', "")

        #print len(cmd_user)
        
        # check if there is a command
        if len(cmd_user) == 0:
                if len(sys.argv) >= 2:
                        cmd_user = sys.argv[1]
                else:
                        rospy.logerr("no command to interprete defined, try _command:=\"command\"")
                        sys.exit()
        
        rospy.loginfo("execute command: " + cmd_user)
        rospy.loginfo("stdout on: " + topicStdOut)
        rospy.loginfo("stderr on:  " + topicStdErr)
        rospy.loginfo("stdin on:  " + topicStdIn)       
        
        # change the buffer mode of the subprocess-shell to linebufferd
        cmd_stdbuf = "stdbuf -o L" 
        cmd = cmd_stdbuf + " " + cmd_user

        process = sp.Popen(cmd.split(" "), stdout=sp.PIPE, stderr=sp.PIPE, stdin=sp.PIPE, bufsize=1)
        rospy.loginfo("started process with pid " + process.pid)        

        pubOUT = rospy.Publisher( topicStdOut, String)
        pubERR = rospy.Publisher( topicStdErr, String)
        subIN  = rospy.Subscriber(topicStdIn,  String, callbackStdIn)
        
        # putting readline of stdout and stderr into non-blocking mode
        fd_out = process.stdout.fileno()
        fl = fcntl.fcntl(fd_out, fcntl.F_GETFL)
        fcntl.fcntl(fd_out, fcntl.F_SETFL, fl | os.O_NONBLOCK)
        
        fd_err = process.stderr.fileno()
        fl = fcntl.fcntl(fd_err, fcntl.F_GETFL)
        fcntl.fcntl(fd_err, fcntl.F_SETFL, fl | os.O_NONBLOCK)
        
        
        while not rospy.is_shutdown():
                try:
                        stdout = process.stdout.readline()
                        if len(stdout) > 0:
                                pubOUT.publish(String(stdout))
                                rospy.loginfo("stdout: " +stdout)
                except Exception as e:
                        pass
                
                try:
                        stderr = process.stderr.readline()
                        if len(stderr) > 0:
                                pubERR.publish(String(stderr))
                                rospy.logerr("stderr: " +stderr)
                except Exception as e:
                        pass
                                
                time.sleep(0.001)
                
                # process is terminated
                if process.poll()!=0:
                        break
        
        #process.terminate()
        ret = process.returncode
        rospy.signal_shutdown('finish')
        sys.exit(ret)