paramiko 登录linux主机后执行tail后返回数据不完整解决方法。

 def get_sql_log(host,port,user,password,key_words,out_put_filename):
     commond='cd crm-app/;./tailall.sh | grep %s'%key_words
     s = paramiko.SSHClient()
     s.set_missing_host_key_policy(paramiko.AutoAddPolicy())
     s.connect(host,port,user,password)
     transport=s.get_transport()
     channel = transport.open_session()
     channel.get_pty()
     channel.exec_command(commond)
     print 'command %s'%commond
    # print '%s' % (str(host))
     f=open(out_put_filename,'a+')

    # f.write(str(dir(s)))
     while 1:
         if channel.exit_status_ready():
             break
         try:
             rl,wl,xl=select.select([channel],[],[],1)
             #print rl
             if len(rl)>0:
                 recv=channel.recv(65536)
                 print recv
                 #print recv
                 #f.seek(2)
                 f.write(str(recv))
                 f.flush()

         except KeyboardInterrupt:
             print("Caught control-C")
　　　　　　　　 channel.send("\x03")#发送 ctrl+c
               channel.close()
               s.close()              exit(0)

之前没有加入   channel.get_pty() ，这个一直返回的信息不完整。

官方文档这样描述：
get_pty(*args, **kwds)

Request a pseudo-terminal from the server. This is usually used right after creating a client channel, to ask the server to provide some basic terminal semantics for a shell invoked with invoke_shell. It isn’t necessary (or desirable) to call this method if you’re going to exectue a single command with exec_command.