shell.py

import paramiko
import time
import re

class ShellHandler:

    def __init__(self, host, user, psw):
        self.ssh = paramiko.SSHClient()
        self.ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
        self.ssh.connect(host, username=user, password=psw, port=22)

        channel = self.ssh.invoke_shell()
        self.stdin = channel.makefile('wb')
        self.stdout = channel.makefile('r')

    def __del__(self):
        self.ssh.close()

    def send_file(self, file_name, source_dir, dest_dir):
        sftp = self.ssh.open_sftp()
        source = source_dir + file_name
        dest = dest_dir + file_name

        sftp.put(source, dest)

    def get_file(self, file_name, source_dir, dest_dir):
        sftp=self.ssh.open_sftp()

        source = source_dir + file_name
        dest = dest_dir + file_name

        sftp.get(source, dest)

    def get_latest_file(self, source_dir, dest_dir):
        sftp=self.ssh.open_sftp()
        latest = 0
        latestfile = None

        sftp.chdir(source_dir)

        for fileattr in sftp.listdir_attr():
            if fileattr.st_mtime > latest:
                latest = fileattr.st_mtime
                latestfile = fileattr.filename

        if latestfile is not None:
            sftp.get(latestfile, dest_dir + latestfile)

    def execute(self, cmd):
        """

        :param cmd: the command to be executed on the remote computer
        :examples:  execute('ls')
                    execute('finger')
                    execute('cd folder_name')
        """
        cmd = cmd.strip('\n')
        self.stdin.write(cmd + '\n')
        finish = 'end of stdOUT buffer. finished with exit status'
        echo_cmd = 'echo {} $?'.format(finish)
        self.stdin.write(echo_cmd + '\n')
        shin = self.stdin
        self.stdin.flush()

        shout = []
        sherr = []
        exit_status = 0
        for line in self.stdout:
            if str(line).startswith(cmd) or str(line).startswith(echo_cmd):
                # up for now filled with shell junk from stdin
                shout = []
            elif str(line).startswith(finish):
                # our finish command ends with the exit status
                exit_status = True
                if exit_status:
                    # stderr is combined with stdout.
                    # thus, swap sherr with shout in a case of failure.
                    sherr = shout
                    shout = []
                break
            else:
                # get rid of 'coloring and formatting' special characters
                shout.append(re.compile(r'(\x9B|\x1B\[)[0-?]*[ -/]*[@-~]').sub('', line).
                             replace('\b', '').replace('\r', ''))

        # first and last lines of shout/sherr contain a prompt
        if shout and echo_cmd in shout[-1]:
            shout.pop()
        if shout and cmd in shout[0]:
            shout.pop(0)
        if sherr and echo_cmd in sherr[-1]:
            sherr.pop()
        if sherr and cmd in sherr[0]:
            sherr.pop(0)

        return shin, shout, sherr