python - 如何使用带标准输入的 wall 命令将消息广播到 python 中的所有 bash 终端？

Question

我想向我的 raspbian 上的所有 bash 终端广播消息。

我知道有 wall 命令来执行该步骤，我可以使用 os.system python 模块来执行命令。

但是，运行命令“wall text.txt”需要 sudo 权限。有什么方法可以将 wall 命令与 python 的标准输入一起使用吗？

Answer 1

确实需要 super 用户才能使用输入文件运行 wall，man 说:

NAME
     wall - write a message to users

SYNOPSIS
     wall [file]

DESCRIPTION
     Wall displays the contents of file or, by default, its standard input, on the terminals of all currently logged in users.

     Only the super-user can write on the terminals of users who have chosen to deny messages or are using a program which automatically denies messages.

     Reading from a file is refused when the invoker is not superuser and the program is suid or sgid.

但是你可以这样做:

$ echo hello hello >text.txt
$ python                    
Python 2.7.1 (r271:86832, Mar 18 2011, 09:09:48) 
[GCC 4.5.0 20100604 [gcc-4_5-branch revision 160292]] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>> os.system('cat text.txt | wall')

Broadcast Message from mak@vader                                             
        (/dev/pts/14) at 10:31 ...                                             

hello hello                                                                    


Broadcast Message from mak@vader                                            
        (/dev/pts/14) at 10:31 ...                                             

hello hello                                                                    

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