PHP: popen - Manual

Описание

resource popen ( string command, string mode )

Открывает поток к процессу, выполняемую при помощи форкинга (forking) комманды, заданной в command.

Возвращает файловый указатель, идентичный возвращаемому функцией fopen(), за исключением того, что он односторонний (может быть использован только для чтения или записи) и должен быть закрыт при помощи pclose(). Этот указатель может быть использован с fgets(), fgetss() и fwrite().

В случае возникновения ошибки, возвращает FALSE.

Замечание: Если вы ищите двустороннюю связь, используйте proc_open().

Пример 1. Пример использования функции popen()

<?php $handle = popen("/bin/ls", "r"); ?>

Если комманда для выполнения не может быть найдена, будет возвращён действующий ресурс. Это может выглядить странно, но имеет смысл; это даёт вам возможность получить доступ к любому сообщению об ошибке, которое вернёт оболочка:


<?php



error_reporting(E_ALL);







/* Добавляем перенаправление чтобы прочитать stderr. */



$handle = popen('/path/to/spooge 2>&1', 'r');



echo "'$handle'; " . gettype($handle) . "\n";



$read = fread($handle, 2096);



echo $read;



pclose($handle);



?>

Замечание: В случае работы в безопасном режиме, вы можете запускать что-либо только в пределах safe_mode_exec_dir. В настоящее время, использование .. в пути запрещено

Внимание

В случае работы в безопасном режиме, все слова, следующие за начальной командой, рассматриваются как единый аргумент. То есть echo y | echo x будет работать как echo "y | echo x".

См. также описание функций pclose(), fopen() и proc_open().

add a note User Contributed Notes
popen

PGP Dude
07-May-2005 01:52


I should say, my host uses a modified form of safe mode, so I don't know if that might have caused a problem with "popen" as opposed to "proc_open".  The warning below does NOT appear on the proc_open page:



quote:

With safe mode enabled, all words following the initial command string are treated as a single argument. Thus, echo y | echo x becomes echo "y | echo x".

PGP Dude
06-May-2005 03:30


LinixDude010's srcipt did not work for me.  Seems wrong to read and write with popen, according to the manual.



The script produced pgp text, but there was something wrong with the text and I could not decode it.



This replacement script, using proc_open, which can read and write, DOES work:



<?php

function pgp_encrypt($keyring_location, $public_key_id, $plain_text) {

  $encrypted_text='';

  $key_id = EscapeShellArg($public_key_id);

  putenv("PGPPATH=$keyring_location");



  // encrypt the message

  $descriptorspec = array(

    0 => array("pipe", "r"),  // stdin

    1 => array("pipe", "w"),  // stdout

    2 => array("pipe", "w")   // stderr ?? instead of a file

  );

  $process = proc_open("pgpe -r $key_id -af", $descriptorspec, $pipes);

  if (is_resource($process)) {

    fwrite($pipes[0], $plain_text);

    fclose($pipes[0]);

    while($s= fgets($pipes[1], 1024)) {

          // read from the pipe

          $encrypted_text .= $s;

    }

    fclose($pipes[1]);

    // optional:

    while($s= fgets($pipes[2], 1024)) {

      $encrypted_text.= "\n<p>Error: $s</p>\n";

    }

    fclose($pipes[2]);

  }

  return $encrypted_text;

}



$message = pgp_encrypt("/home/username/.pgp", "to@domain.com", "dummy text to be encrypted");

print nl2br($message);



?>

shaun at nospam dot phplabs dot com
27-Feb-2005 08:52


Note that there appears to be a limit to the amount of data that fread() will return from a handle opened with popen(). A call to fread() may not return as much as you ask for.



For example, suppose I have a file "myfile.txt" which is more than 10KB in size. The following code works as expected:



<?php

$fp = fopen('myfile.txt', 'r');

$data = fread($fp, 10240);

echo strlen($data);

?>



The output is '10240.' However, popen() behaves differently:



<?php

$fp = popen('/bin/cat myfile.txt', 'r');

$data = fread($fp, 10240);

echo strlen($data);

?>



On my system, this code prints out '8192' instead of the expected '10240.'

webmaster at elcurriculum dot com
09-Dec-2004 03:05


This function send an email in html format.



function SendEmail($to,$asunto,$html,$from) {

    $fd = popen("/usr/sbin/sendmail -t", "w");

    fputs($fd, "Content-type: text/html\r\n");

    fputs($fd, "To: $to\r\n");

    fputs($fd, "From: TRYKE <" . $from . ">\r\n");

    fputs($fd, "Subject: $asunto\r\n");

    fputs($fd, "X-Mailer: PHP3\r\n\r\n");

    fputs($fd, $html);

    pclose($fd);

}



Examples:

SendEmail("tryke@hot.com","My Subject","<h1>Hi,<br>How are you?</h1>","miemail@midomain.com");



More:

http://tryke.blogcindario.com

kalvinb602 at hotmail dot com
06-Jul-2004 06:42


If you're having trouble with the server (Apache) hanging when issuing system commands consider the following bug report:



http://bugs.php.net/bug.php?id=22526



basically, if you're using sessions issue a 



session_write_close();



command before you execute your system command to keep the server from hanging.



This may also correct the problem when using other system command executing functions like exec.



Ben

Michel Machado
06-Mar-2004 08:53


Yet another workaround for not having bidirectional pipes in php.



$Cmd =

"bc 2>&1 << END\n" .

"100+221\n" .

"1+3*3\n" .

"quit\n" .

"END\n";



$fp = popen($Cmd, 'r');

$read = fread($fp, 1024);

echo $read;

pclose($fp);

http://vmlinuz.nl/about/contact/
11-Nov-2002 11:58


From the popen linux programmers manual:

<quote>The  command  argument  is  a pointer to a null-terminated string containing a shell command line.  This  command  is passed  to  /bin/sh  using the -c flag.</quote>



Since php uses this popen function, you need to be sure /bin/sh exists. This file may not exist in chroot()ed environments.

ajv-php at erkle dot org
08-Aug-2002 02:02


I noticed that some of the examples above seem to advocate passing unencrypted data to gpg via the pipe shell escape, in the absence of a bi-directional popen (on some OSes).



The approach I've taken is similar to:



  $prefix = 'example';

  $command = '/usr/local/bin/gpg --encrypt --armor --no-tty --batch --no-secmem-warning --recipient "joe.soap@example.com"';

  $tmpfile = tempnam('/tmp', $prefix);

  $pipe = popen("$command 2>&1 >$tmpfile", 'w');

  if (!$pipe) {

    unlink($tmpfile);

  } else {

    fwrite($pipe, $plaintxt, strlen($plaintxt));

    pclose($pipe);

    $fd = fopen($tmpfile, "rb");

    $output = fread($fd, filesize($tmpfile));

    fclose($fd);

    unlink($tmpfile);

  }

  return $output;



This means that unencrypted information is not passed via a (potentially readable) shell command, and only encrypted information gets stored on disc.

12-Jul-2002 05:33


Here is a workaround for not having bidirectional pipes in php.



If you have bidirectional pipe support, don't bother with this.



The trick here is to send the input on the command line to the target application.  In particular I wanted to use openssl without using temp files or named pipes.  This solution should also be thread/process safe.



This does work on Linux (RedHat 7).



function filterThroughCmd($input, $commandLine) {

  $pipe = popen("echo \"$input\"|$commandLine" , 'r');

  if (!$pipe) {

    print "pipe failed.";

    return "";

  }

  $output = '';

  while(!feof($pipe)) {

    $output .= fread($pipe, 1024);

  }

  pclose($pipe);

  return $output;

}



# example:

print filterThroughCmd("hello", "cat");

# Piping to cat has the effect of echoing your input.

cyberlot at cyberlot dot net
30-Jun-2002 04:29


The below code works for both way processing ;) Have fun folks



<?

    system("mkfifo pipeout");

   $pipe = popen("./nwserver -module Chapter1E > pipeout","w");

   $pipeout = fopen("pipeout", "r");

   while ($s = fgets($pipeout,1024)) {

    echo $s;

   }



?>

linuxdude010 at yahoo dot com
24-May-2002 02:49


I had all kinds of trouble encrypting a message with PGP, but I finanlly got it to work.  The trick was to 'chmod o+r pubring.pkr' so that the apache server could read the public keys!!!  Then, this function worked fine:



<?PHP

function pgp_encrypt($keyring_location, $public_key_id, $plain_text) {



        $key_id = EscapeShellArg($public_key_id);

        putenv("PGPPATH=$keyring_location");



        // encrypt the message

        $pipe = popen("pgpe -r $key_id -af", "r");               

        fwrite($pipe, $plain_text);

        $encrypted_text = '';

        while($s = fgets($pipe, 1024)) {

                // read from the pipe

                $encrypted_text .= $s;

        }

        pclose($pipe);



        return $encrypted_text;

}



$message = pgp_encrypt("/home/username/.pgp", "to@domain.com", "dummy text to be encrypted");

print nl2br($message);



?>

nricciardi at mindspring dot com
08-Mar-2002 07:38


ive tried using popen using bidirectional pipes without working for obvious reasons, but i managed to create a simple script that managed to take care of the problem.  This example is for gpg encryption.



<?

   $message = "this is the text to encrypt with gpg";

   $sendto = 'Dummy Key <another@fake.email>';



   system("mkfifo pipein");

   system("mkfifo pipeout");

   system("gpg --encrypt -a -r '$sendto' > pipeout < pipein &");

   $fo = fopen("pipeout", "r");

   $fi = fopen("pipein", "w");

   fwrite($fi, $message, strlen($message));

   fclose($fi);

   while (!feof($fo)) {

      $buf .= fread($fo, 1024);

   }

   echo $buf;

   unlink("pipein");

   unlink("pipeout");

?>



If anyone has a better way of doing this I would love to see it.

kevin at pricetrak dot com
29-Jun-2001 02:26


Just a quick note about your environment. None of the apache specific environment variables are available to the called program.

trevor at verite dot com
16-Feb-2001 03:42


Just make sure that you check the user information being passed into the command (if any) before it executes.

bevmo at gmx dot de
01-Dec-2000 01:27


Try this if you want to use sendmail...


$mailer = popen ("/usr/sbin/sendmail -t -i","w");


fwrite ($mailer,"Subject: 


From: 


To: 




*insert text*


");


pclose ($mailer);

stevet at linuxfan dot com
13-Nov-2000 10:17


In PHP3, I could do:




$query = "echo hello world | mycmd"


$fp = ($query, "r");




Under PHP4, this just produces "hello world | mycmd" as the output - the pipe is not executed.




Instead, use:




$query = "hello world";


$cmd = "mycmd";


$fp = popen($cmd, "w+");


fwrite($fp, $query);

lexzeus at mifinca dot com
08-Nov-2000 12:53


Try this (if you're familiar with vi editor) :




<?php


$f=popen("vi newfile.txt","w");


sleep(1);


fputs($f,"i");  // insert




sleep(1);


fputs($f,"Hello world\r"); // write the text to vi Editor




sleep(1);


fputs($f,chr(27));  // cancel action




sleep(1);


fputs($f,":wq\r");  // write and quit




pclose($f); // back to php




exit;


?>





heh heh heh,




LexZEUS

matthew at leftcoast dot com
04-Oct-2000 09:16


Note that your OS must support bi-direction pipes for popen to be bi-directional.  




FreeBSD and BSDI are known to support bi-pipes.  




Not sure about Linux.

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