how to get output of proc_open()

Question

I've tried to get output from proc_open method in php, but, when I print it, I got empty.

$descriptorspec = array(
    0 => array("pipe", "r"),
    1 => array("pipe", "w"),
    2 => array("file", "files/temp/error-output.txt", "a")
);

$process = proc_open("time ./a  a.out", $descriptorspec, $pipes, $cwd);

as long as I know, I can get the output with stream_get_contents()

echo stream_get_contents($pipes[1]);
fclose($pipes[1]);

But I can't do that.. any suggestion?

Thx before...

Haha, your code actually made me understand how proc_open works. — Yoshiyahu, May 03 '12 at 19:24

score 13 · Accepted Answer · answered May 16 '11 at 11:34

Your code more or less works for me. time prints its output to stderr so if you're looking for that output, look in your file files/temp/error-output.txt. The stdout pipe $pipes[1] will only contain the output of the program ./a.

My repro:

[edan@edan tmp]$ cat proc.php 

<?php

$cwd='/tmp';
$descriptorspec = array(
    0 => array("pipe", "r"),
    1 => array("pipe", "w"),
    2 => array("file", "/tmp/error-output.txt", "a") );

$process = proc_open("time ./a a.out", $descriptorspec, $pipes, $cwd);

echo stream_get_contents($pipes[1]);
fclose($pipes[1]);

?>

[edan@edan tmp]$ php proc.php 

a.out here.

[edan@edan tmp]$ cat /tmp/error-output.txt

real    0m0.001s
user    0m0.000s
sys     0m0.002s

Thx for your help... I don't check my stderr... finally, I checked it, and found the output... thanks.. — Bobby Stenly, May 16 '11 at 13:18

score 12 · Answer 2 · edited Dec 19 '16 at 06:12

12

this is another example with proc_open(). I am using Win32 ping.exe command in this example. CMIIW

set_time_limit(1800);
ob_implicit_flush(true);

$exe_command = 'C:\\Windows\\System32\\ping.exe -t google.com';

$descriptorspec = array(
    0 => array("pipe", "r"),  // stdin
    1 => array("pipe", "w"),  // stdout -> we use this
    2 => array("pipe", "w")   // stderr 
);

$process = proc_open($exe_command, $descriptorspec, $pipes);

if (is_resource($process))
{

    while( ! feof($pipes[1]))
    {
        $return_message = fgets($pipes[1], 1024);
        if (strlen($return_message) == 0) break;

        echo $return_message.'<br />';
        ob_flush();
        flush();
    }
}

Hope this helps =)

edited Dec 19 '16 at 06:12

LF00

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answered Mar 25 '13 at 04:44

Didit Dwianto

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Why do you need ob_flush and flush in this? – nidhimj22 Feb 24 '16 at 14:37
1

To summarize: "flush() may not be able to override the buffering scheme of your web server and it has no effect on any client-side buffering in the browser. It also doesn't affect PHP's userspace output buffering mechanism. This means you will have to call both ob_flush() and flush() to flush the ob output buffers if you are using those. " Source: http://www.php.net/manual/en/function.flush.php – Didit Dwianto Dec 22 '16 at 08:19

how to get output of proc_open()

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