passthru

(PHP 4, PHP 5, PHP 7, PHP 8)

passthruEsegue un programma esterno e mostra l'output non elaborato

Descrizione

passthru(string $command, int &$return_var = ?): void

La funzione passthru() è simile alla funzione exec() in quanto esegue un command. Questa funzione deve essere usata al posto di exec() o di system() quando l'output del comando Unix consiste in dati binari che devono essere restituiti direttamente al browser. Un suo uso frequente consiste nell'eseguire, ad esempio, le utility pbmplus che possono restituire un flusso diretto all'immagine. Impostando il Content-type a image/gif e successivamente chiamando un programma pbmplus per generare una gif, si possono creare degli script PHP che generano direttamente delle immagini.

Elenco dei parametri

command

Il comando che verrà eseguito.

return_var

Se viene specificato il parametro return_var, lo stato ritornato dal comando Unix verrà posto lì.

Valori restituiti

Nessun valore viene restituito.

Note

Avviso

Se si permette di passare a questa funzione i dati provenineti dagli input utente, si dovrebbe utilizzare la funzione escapeshellarg() oppure escapeshellcmd() in modo da essere sicuri che gli utenti non possano compromettere il sistema eseguendo comandi arbitrari.

Nota:

Se si avvia un programma con questa funzione e si vuole lasciarlo in esecuzione in background, ci si deve accertare che l'output del programma venga redirezionato verso un file o qualche altro stream di output, altrimenti PHP si fermerà finché l'esecuzione del programma sarà terminata.

Vedere anche:

add a note add a note

User Contributed Notes 23 notes

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17
puppy at cyberpuppy dot org
19 years ago
Regarding swbrown's comment...you need to use an output buffer if you don't want the data displayed.

For example:
ob_start();
passthru("<i>command</i>");
$var = ob_get_contents();
ob_end_clean(); //Use this instead of ob_flush()

This gets all the output from the command, and exits without sending any data to stdout.
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11
igor at bboy dot ru
19 years ago
If you are using passthru() to download files (for dynamically generated content or something outside webserver root) using similar code:

header("Content-Type: application/octet-stream");
header("Content-Disposition: attachment; filename=\"myfile.zip\"");
header("Content-Length: 11111");
passthru("cat myfile.zip",$err);

and your download goes fine, but subsequent downloads / link clicks are screwed up, with headers and binary data being all over the website, try putting

exit();

after the passthrough. This will exit the script after the download is done and will not interfere with any future actions.
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7
jo at durchholz dot org
17 years ago
Note to Paul Giblock: the command *is* run through the shell.
You can verify this on any Linux system with

<?php
passthru
('echo $PATH');
?>

You'll get the content of the PATH environment variable, not the string $PATH.
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2
divinity76+spam at gmail dot com
2 years ago
if you have problems with passthru("docker-compose ...bash") losing interactive shell size information, try using proc_open instead, for some reason docker-compose bash knows the size of the outer terminal when i use use proc_open, but loses that information when i use passthru,

eg i replaced
<?php
passthru
("docker-compose -f docker-compose.yml bash",$ret);
?>
with
<?php
$empty1
=array();
$empty2=array();
$proc=proc_open("docker-compose -f docker-compose.yml bash",$empty1,$empty2 );
$ret = proc_close($proc);
?>

and suddenly docker-compose bash knew my terminal size :)
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3
sarel dot w at envent dot co dot za
19 years ago
Zak Estrada
14-Dec-2004 11:21
Remember to use the full path (IE '/usr/local/bin/foo' instead of 'foo') when using passthru, otherwise you'll get an exit code of 127 (command not found).

Remember, you'll also get this error if your file does not have executable permission.
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3
myselfasunder at gmail dot com dot dfvuks
14 years ago
PHP's program-execution commands fail miserably when it comes to STDERR, and the proc_open() command doesn't work all that consistently in non-blocking mode under Windows.

This command, although useful, is no different. To form a mechanism that will see/capture both STDOUT and STDERR output, pipe the command to the 'tee' command (which can be found for Windows), and wrap the whole thing in output buffering.

Dustin Oprea
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2
Zak Estrada
20 years ago
Remember to use the full path (IE '/usr/local/bin/foo' instead of 'foo') when using passthru, otherwise you'll get an exit code of 127 (command not found).
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1
mail at dtrasbo dot dk
2 years ago
To capture the output of a command in a string without using output buffer functions, use shell_exec()
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1
Chroot
16 years ago
If you have chrooted apache and php, you will also want to put /bin/sh into the chrooted environment. Otherwise, the exec() or passthru() will not function properly, and will produce error code 127, file not found.
up
0
tox at novasonica dot com
5 years ago
I was trying to implement a system that allows running arbitrary CLI commands with parameters, but I kept running into the issues with user prompts from the command as they would let execution hang. The solution is simple: just use passthru() as it outputs everything and correctly handles user prompts out of the box.
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0
stuartc1 at NOSPAM dot hotmail dot com
19 years ago
Thought it might beuseful to note the passthru seems to supress error messages whilst being run in Dos on Windows (test on NT).

To show FULL raw output including errors, use system().
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0
swbrown at ucsd dot edu
21 years ago
passthru() seems absolutely determined to buffer output no matter what you do, even with ob_implicit_flush().  The solution seems to be to use popen() instead.
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0
kpierre at fit dot edu
22 years ago
The documention does not mention that passthru() will only display standard output and not standard error.

If you are running a script you can pipe the STDERR to STDOUT by doing

exec 2>&1

Eg. the script below will actually print something with the passthru() function...

#!/bin/sh
exec 2>&1
ulimit -t 60
cat nosuchfile.txt
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-1
nuker at list dot ru
18 years ago
I wrote function, that gets proxy server value from the Internet Explorer (from
registry). It was tested in Windows XP Pro

(Sorry for my English)

<?php
function getProxyFromIE()
{
       
exec("reg query \"HKEY_CURRENT_USER\Software\Microsoft".
       
"\Windows\CurrentVersion\Internet Settings\" /v ProxyEnable",
       
$proxyenable,$proxyenable_status);

       
exec("reg query \"HKEY_CURRENT_USER\Software\Microsoft".
       
"\Windows\CurrentVersion\Internet Settings\" /v ProxyServer",
       
$proxyserver);

        if(
$proxyenable_status!=0)
        return
false; #Can't access the registry! Very very bad...
       
else
        {
       
$enabled=substr($proxyenable[4],-1,1);
        if(
$enabled==0)
        return
false;
        else
        {
       
$proxy=ereg_replace("^[ \t]{1,10}ProxyServer\tREG_SZ[ \t]{1,20}","",
       
$proxyserver[4]);

        if(
ereg("[\=\;]",$proxy))
        {
            
$proxy=explode(";",$proxy);
             foreach(
$proxy as $i => $v)
             {
                   if(
ereg("http",$v))
                   {
                  
$proxy=str_replace("http=","",$v);
                   break;
                   }
             }
             if(@!
ereg("^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\:".
            
"[0-9]{1,5}$",$proxy))
             return
false;
             else
             return
$proxy;
        }
        else
        return
$proxy;
        }

        }
}
?>
Note, that this function returns FALSE if proxy is disabled in Internet
Explorer. This function returns ONLY HTTP proxy server.

Usage:
<?php
$proxy
=getProxyFromIE();
if(!
$proxy)
echo
"Can't get proxy!";
else
echo
$proxy;
?>
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-1
Stuart Eve
19 years ago
I dunno if anyone else might find this useful, but when I was trying to use the passthru() command on Suse9.3 I was having no success with the command:

$command = 'gdal_translate blahahahaha';

passthru($command);

It only worked once I put:

$command = '/usr/bin/local/gdal_translate blalalala';

passthru($command);
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-4
Paul Giblock
17 years ago
Stuart:

The pasthru function does not execute the program through the shell.  What this mean, among other things, is that your PATH variable is never set.  Therefore, you have to use full paths on everything.

I believe system() will run your program underneith a shell.  This allow the program to run in a 'normal' environment.

-Paul
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-4
vijayramanan at rediffmail dot com
19 years ago
I had an issue when i used exec

I think we were echoing information on the test.php script.
for eg: when we tried

exec(php test.php,$array,$error);

the return was 127 and the code was failing.

checking the note on this page gave us a hint to use passthru instead.
The only thing to note is that you need to provide the fuull path.

now our command became

passthru(/bin/php /pathtotest/test.php,$array,$error);

this works.

yipeee!!!!!
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-3
sidney at jigsaw dot nl
23 years ago
PJ's ulimit example is nice; however, if you include multiple commands in the script after the ulimit command, each gets its own, seperate 60 second time slot!<br>

Furthermore, these sixty seconds are *CPU* time. Most programs hang for other reasons than CPU hogging (for example, waiting for a database connection) so for most purposes the number 60 is rather too high.<br>

Try "ulimit -t 1" first, which will give you about 10^9 cycles on modern hardware -- quite enough to get a lot of work done!
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-3
PJ at piggei dot com
23 years ago
About the problem of zombies, you may call a bash script like this:

--------------------------
#! /bin/bash
ulimit -t 60

<your command here>
--------------------------
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-9
me at yourMomsPussy dot cum
8 years ago
`command` // back ticks drop you out of PHP mode into shell
exec('command', $output); // exec will allow you to capture the return of a command as reference
shell_exec('command'); // will return the output to a variable
system(); //as seen above.
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-6
php @ richud dot com
20 years ago
Regarding kpierre's post, be mindful that if you shell script errors, you will find the error output from it in the base error_log file (not virtualhost error_log) in apache.
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-8
andreas dot hochsteger at oeamtc dot at
23 years ago
If you sometimes get no output from passthru() use system() instead. This solved this problem for me (php 4.0.5 on Tru64 Unix compiled with gcc).
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-8
jcr at marvel-databadge dot com
21 years ago
With apache 2.x on RH9 passthru() writes 1 byte at a time. Apache 2.x buffers and chunk encodes the output for you - but the chunked encoding devides the output in chunks of 1 byte each...thus several bytes of overhead per byte. I guess that buffering behaviour is by design - but caused problems for me with IE adobe acrobot 5 plugin. The plugin doesn't like like it if you send it a stream of 1 byte chunks - it tells you your file is not a pdf or gives a blank screen. Using output buffering (ob_start / ob_endflush) gives reasonable size chunks and the plugin works OK.
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