xinetd 服务调用 python 脚本（无法正确执行）

我读到了这个：

您可以使用 xinetd 添加启动 python 脚本的服务。标准输入和输出将通过网络在所需端口上传输，因此您不需要修改脚本（input/raw_input 和 print 方法可以正常工作）。

因此，当建立到 192.168.240.37:65123 的 TCP 连接时，我使用自定义 xinet 服务来启动 script.py。该行为不符合期望/预期。

/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“很难确切地说出这里发生了什么”时，我的意思是很难判断上面的输出中“输入你的名字：”提示后出现的“John Smith”是否是 print 语句的结果，并且很难判断“连接被外部主机关闭”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

正如你所看到的，我在 netcat 中得到了非常相似的行为。

对我来说真正的问题显然是我缺乏套接字编程知识。我在网上搜索“xinetd python no data”时发现了这篇文章（https://mail.python.org/pipermail/python-list/2007-July/423659.html）这至少帮助我让我的东西工作起来，并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 并将其替换为帖子中的概念。

/root/script.py（原始）

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

/root/script.py （修改并工作）

#! /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 - 工作）

[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.