xinetd服务调用python脚本（无法正确执行）

Question

我读到这个：

您可以使用xinetd添加服务以启动python脚本。 标准输入和输出将通过网络在所需的端口上传输，因此您无需修改​​脚本（input / raw_input和print方法可以正常工作）。

结果，当建立到192.168.240.37:65123的TCP连接时，我正在使用自定义的xinet服务来启动script.py。 该行为不是期望/预期的。

/root/script.py

#! /usr/bin/python
my_name = raw_input("Enter your name: ")
print my_name
quit()

/etc/xinetd.d/netunique-server

service netunique
{
    disable         = no
    id              = netunique-server
    type            = unlisted
    wait            = no
    socket_type     = stream
    protocol        = tcp
    user            = root
    server          = /usr/bin/python
    server_args     = /root/script.py
    port            = 65123
    flags           = IPv4 REUSE
    bind            = 192.168.240.37
}

systemctl状态xinetd

Nov 11 21:24:00 netunique.ourhome.com xinetd[2161]: xinetd Version 2.3.15 started with libwrap loadavg labeled-ne... in.
Nov 11 21:24:00 netunique.ourhome.com xinetd[2161]: Started working: 1 available service

telnet 192.168.240.37 65123（预期的行为）

[root@netunique xinetd.d]# telnet 192.168.240.37 65123
Trying 192.168.240.37...
Connected to 192.168.240.37.
Escape character is '^]'.
Enter your name: John Smith          <-- I type name after prompt here
John Smith                           <-- Script prints entry back to screen
Connection closed by foreign host.   <-- Script does its quit()   

telnet 192.168.240.37 65123（实际行为）

[root@netunique xinetd.d]# telnet 192.168.240.37 65123
Trying 192.168.240.37...
Connected to 192.168.240.37.
Escape character is '^]'.
<blank>                              <-- no prompt as expected
John Smith                           <-- I enter some data and hit Enter
Enter your name: John Smith          <-- Hard to tell exactly what happened here
Connection closed by foreign host.   <-- Hard to tell exactly what happened here
[root@netunique xinetd.d]# 

当我说“很难说出这里到底发生了什么”时，我的意思是很难说出上面输出中的“ John Smith”是否出现在“输入您的名字：”提示后，是打印语句的结果，判断“外部主机关闭的连接”是否是quit（）语句的结果。

nc 192.168.240.37 65123（实际行为）

[root@netunique xinetd.d]# nc 192.168.240.37 65123
<blank>                              <-- no prompt as expected
John Smith                           <-- I enter some data and hit Enter
Enter your name: John Smith          <-- Hard to tell exactly what happened here
                                     <-- Nothing happened here, I hit Enter
                                     <-- I hit Enter again
Ncat: Broken pipe.                   <-- This is the end result

如您所见，netcat的行为非常相似。

Answer 1

对我来说，真正的问题显然是我缺乏套接字编程知识。 我发现此帖子在线搜索“ xinetd python no data”（ https://mail.python.org/pipermail/python-list/2007-July/423659.html ），这至少对我有所帮助。通过示例说明了套接字编程的实际工作原理。 解决方案如下，我从原始脚本中删除了raw_input并用文章中的概念替换了它。

/root/script.py（原始）

#! /usr/bin/python
my_name = raw_input("Enter your name: ")
print my_name
quit()

/root/script.py（已修改且可以正常使用）

#! /usr/bin/python
import sys
print "Enter your name:"                
sys.stdout.flush()
my_name = sys.stdin.readline().strip()
print "Your name is %s" % my_name
sys.stdout.flush()
quit()

telnet 192.168.240.37 65123（实际行为-运行）

[root@netunique ~]# telnet 192.168.240.37 65123
Trying 192.168.240.37...
Connected to 192.168.240.37.
Escape character is '^]'.
Enter your name:
Bob Smith
Your name is Bob Smith
Connection closed by foreign host.