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Date: Thu, 28 May 2009 17:21:43 +0400
Lines: 49
Subject: Re: [PHP-DEV] shell_exec, environment, and multithreading servers
From: dmda@yandex.ru ("jvlad")

>> Recently I faced with one funny problem in PHP. Seems there is no way to 
>> run
>> a sub-process using exec() (or backticks), and pass there specially
>> crafted environment without affecting all running threads. As soon as I
>> update the environment, all other threads see the change. It's
>> multithreading nature to be running under the same process and share the
>> process environment, no problems so far, but there should be a way to run
>> sub-process with appropriate set of environment variables without 
>> affecting
>> all the threads.
>>
>> Looks like for Win32 target, there is a popenex() function that is called 
>> by
>> shell_exec and this function has env parameter. I think it makes sense to
>> pass $_ENV in this argument. Certainly, $_ENV should be converted into 
>> array
>> of pointers.
>> Not sure if there is any way under unix other than using execXX() instead
>> of popen() to get the same behaviour.
>>
>> Thoughts?
>>
>> -jv

>Does resource proc_open ( string $cmd , array $descriptorspec , array
>&$pipes [, string $cwd [, array $env [, array $other_options ]]] ) for
>the bill here?

That's correct, but what to do with existing code that I need to use?
I don't want to replace all constructs like $a = `$mycmd $cmdline`; with
many lines required for popenex(). I would not like this way even if only 
one symbol
should be changed in the 3rd party code.

Why not to enhance semantic of exec() and backticks functions? Why not to
run child process with copy of $_ENV[] instead of current process 
envrironment?
With multithreading servers  you can't change current process's enviroment
without affecting all the threads, but you can easily and safely change 
$_ENV[].

-jv