forking multiple processes at a time

[SomeGei]

i have a php script that needs to execute an external php script (call this
script 2) when the user clicks a link, however I don't want the user to have
to wait until script 2 finishes executing before he sees the output of
script one... i know I can use the exec() command to do this, and use the &
to run the command in the background....

but say i want to run 100 instances of script 2 when the user clicks the
link (with different arguments)... i dont want to have all 100 processes
running at the same time... what I would like to do is run 10 or so at once,
and once those 10 are completed, run another 10...

how would i accomplish this?

[Dani CS]

Re: forking multiple processes at a time

SomeGei wrote:[color=blue]
> i have a php script that needs to execute an external php script (call this
> script 2) when the user clicks a link, however I don't want the user to have
> to wait until script 2 finishes executing before he sees the output of
> script one... i know I can use the exec() command to do this, and use the &
> to run the command in the background....
>
> but say i want to run 100 instances of script 2 when the user clicks the
> link (with different arguments)... i dont want to have all 100 processes
> running at the same time... what I would like to do is run 10 or so at once,
> and once those 10 are completed, run another 10...
>
> how would i accomplish this?[/color]

Could the last process of each batch launch the next 10 processes?

Another approach is using cron and having script 1 store in a file the
arguments for the 100 instances of script 2. cron would run a "launcher"
every minute, and this launcher would execute a copy of script 2 for
each set of arguments in the file.

[Pedro Graca]

Re: forking multiple processes at a time

SomeGei wrote:[color=blue]
> i dont want to have all 100 processes running at the same time...
> what I would like to do is run 10 or so at once,
> and once those 10 are completed, run another 10...
>
> how would i accomplish this?[/color]

Check out popen() and related functions

http://www.php.net/popen

<?php // basic code with no error-checking
for ($i=0; $i<10; ++$i) {

/* open ten processes */
for ($j=0; $j<10; ++$j) {
$pipe[$j] = popen('script2. php', 'w');
}

/* wait for them to finish */
for ($j=0; $j<10; ++$j) {
pclose($pipe[$j]);
}
}
?>
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[Chung Leong]

Re: forking multiple processes at a time


"SomeGei" <some@gei.com > wrote in message
news:qJudnUpNpr 0n50ncRVn-rQ@giganews.com ...[color=blue]
> i have a php script that needs to execute an external php script (call[/color]
this[color=blue]
> script 2) when the user clicks a link, however I don't want the user to[/color]
have[color=blue]
> to wait until script 2 finishes executing before he sees the output of
> script one... i know I can use the exec() command to do this, and use the[/color]
&[color=blue]
> to run the command in the background....
>
> but say i want to run 100 instances of script 2 when the user clicks the
> link (with different arguments)... i dont want to have all 100 processes
> running at the same time... what I would like to do is run 10 or so at[/color]
once,[color=blue]
> and once those 10 are completed, run another 10...
>
> how would i accomplish this?
>
>[/color]

Have each instance of the program spawn a copy of itself when it finishes.

[R. Rajesh Jeba Anbiah]

Re: forking multiple processes at a time

SomeGei wrote:[color=blue]
> i have a php script that needs to execute an external php script[/color]
(call this[color=blue]
> script 2) when the user clicks a link, however I don't want the user[/color]
to have[color=blue]
> to wait until script 2 finishes executing before he sees the output[/color]
of[color=blue]
> script one... i know I can use the exec() command to do this, and use[/color]
the &[color=blue]
> to run the command in the background....[/color]
<snip>

http://in.php.net/system

<quote>
Note: If you start a program using this function and want to leave it
running in the background, you have to make sure that the output of
that program is redirected to a file or some other output stream or
else PHP will hang until the execution of the program ends.
</quote>

--
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