[Python-Dev] Alternative to os.system that takes a list of strings?

[Guido van Rossum]

> Hi.  I've found it convenient to use the function below to make system
> calls, as I sometimes the strings I need to pass as arguments confuse
> the shell used in os.system.  I was wondering whether it's worth passing
> this upstream.  The main problem with doing so is that I have no idea
> how to implement it on Windows, as I can't use the os.fork and os.wait*
> functions in that context.
> 
> Alex.

Hi Alex,

This functionality is alrady available through the os.spawn*() family
of functions.  This is supported on Unix and Windows.

BTW, what do you mean by "upstream"?

--Guido van Rossum (home page: http://www.python.org/~guido/)

> import os
> 
> def system(command, args, environ=os.environ):
> 
>     '''The 'args'  variable is  a sequence of  strings that are  to be
>     passed as the arguments to the command 'command'.'''
> 
>     # Fork off a process to be replaced by the command to be executed
>     # when 'execve' is run.
>     pid = os.fork()
>     if pid == 0:
> 
>         # This is the child process; replace it.
>         os.execvpe(command, [command,] + args, environ)
> 
>     # In the parent process; wait for the child process to finish.
>     return_pid, return_value = os.waitpid(pid, 0)
>     assert return_pid == pid
>     return return_value
> 
> if __name__ == '__main__':
> 
>     print system('/bin/cat', ['/etc/hosts.allow', '/etc/passwd'])