class RemoteExecutor:
""" Execute a command to the remote host through ssh session. This function
also starts three threads that handle the input, error and output streams.
Then the other functions can be used for conversating with the process.
remexecutor.exec('ls -al') # prints remote home directory contents
"""
def __init__(self, remotehost):
""" Initialize the connection."""
self.__connection = remotehost.connection
self.__env = remotehost.env
self.__session = self.__connection.openSession()
self.__instr = None
self.__errstr = None
self.__inputreader = None
self.__errortreader = None
self.__outputwriter = None
def exec(self,command):
if not self.__connection.isAuthenticationComplete():
print "Connection not established"
return
if self.__session == None:
self.__session = self.__connection.openSession()
sess = self.__session
if type(command) is type([]): # if command is a list make it a string
command = " ".join(command)
# make environment variables to string and assemble command
environment = " ".join(["=".join(i) for i in self.__env])
command = "export " + environment + " && " + command
sess.execCommand(command) # execute command
self.__outputwriter = DataOutputStream(sess.getStdin())
# start a new thread for the input stream of the process and set the
# Reader
self.__instr = StreamGobbler(sess.getStdout())
self.__inputreader = Reader(BufferedReader(InputStreamReader(self.__instr)))
# start a new thread for error stream of the process and set the
# Reader
self.__errstr = StreamGobbler(sess.getStderr())
self.__errorreader = Reader(BufferedReader(InputStreamReader(self.__errstr)))
def input(self):
""" Function for reading the output of a process.
Wrapper for Reader readString function.
"""
if self.__inputreader is None:
print "Error __inputstreamer__ is None"
return
return self.__inputreader.readString()
def error(self):
""" Function for reading the error of a process.
Wrapper for Reader readString function.
"""
if self.__errorreader is None:
print "Error __errorstreamer__ is None"
return
return self.__errorreader.readString()
def write(self, bytes = None):
""" Function to read from system in and write to the process
input (or the proc output)
"""
writer = self.__outputwriter
if bytes is None:
bytes = raw_input()
#for i in bytes[:]:
# print ord(i)
writer.writeBytes(bytes+"\n")
writer.flush()
def getEnv(self, var):
env = self.__env
for i in env:
if var in i:
return i[1]
def setEnv(self, var, value):
env = self.__env
curvar = None
for i in range(len(env)):
if var in env[i]:
curvar = env[i][1]
del env[i]
break
self.__env.append((var,value))
def close(self):
self.__instr.close()
self.__errstr.close()
self.__session.close()
self.__instr = None
self.__errstr = None
self.__session = None
