ssh2_exec: wait end of a process to run next

Question

I am running a command using ssh2_exec, but looks like it runs the $stream2 before the end of $stream1 process. How do I run $stream2 only after the end of $stream1?

<?php
$connection = ssh2_connect('shell.example.com', 22);
ssh2_auth_password($connection, 'username', 'password');

$stream1= ssh2_exec($connection, 'command to run');

$stream2 = ssh2_exec($connection, 'command to run 2');

?>

score 3 · Answer 1 · answered Jul 01 '14 at 01:41

Problem Solved:

@Barmar proposed me to look at php.net/manual/en/function.ssh2-exec.php#59324

I solved the problem by:

<?php
$connection = ssh2_connect('shell.example.com', 22);
ssh2_auth_password($connection, 'username', 'password');

$stream1= ssh2_exec($connection, 'command to run');

stream_set_blocking($stream1, true);

// The command may not finish properly if the stream is not read to end
$output = stream_get_contents($stream1);

$stream2 = ssh2_exec($connection, 'command to run 2');

?>

score 2 · Answer 2 · answered Jul 05 '14 at 20:46

the fact that blocking isn't enabled by default is stupid. this is why i like SSH by phpseclib so much better. stuff just works as expected with phpseclib. eg.

<?php
include('Net/SSH2.php');

$ssh = new Net_SSH2('shell.example.com', 22);
$ssh->login('username', 'password');

$output = $ssh->exec('command to run');
$ssh->exec('command to run 2');
?>

Barmar · Answer 3 · 2014-07-01T00:51:35.090

1

Read everything from the first stream. When it finishes, you know the command is done.

$stream1= ssh2_exec($connection, 'command to run');
stream_get_contents($stream1); // Wait for command to finish
fclose($stream1);

$stream2 = ssh2_exec($connection, 'command to run 2');

edited Jul 01 '14 at 00:51

answered Jul 01 '14 at 00:15

Barmar

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Now it is giving me an error on the $stream2 line. PHP Warning: ssh2_exec(): Unable to request a channel from remote host in XXX.php on line 28 – user3780518 Jul 01 '14 at 00:29
And when I remove the line with stream_get_contents, I get no error. – user3780518 Jul 01 '14 at 00:43
Sorry, I'm not familiar enough with the ssh2 extension to know why that's happening or how to resolve it. – Barmar Jul 01 '14 at 00:45
Try it with the `fclose` I just added. I got the idea from here: http://www.php.net/manual/en/function.ssh2-exec.php#53691 – Barmar Jul 01 '14 at 00:51
If that doesn't work, you may have to resort to the more complicated solution here: http://www.php.net/manual/en/function.ssh2-exec.php#59324 – Barmar Jul 01 '14 at 00:52
Thanks! It worked. I have added the solution in the top of the page. – user3780518 Jul 01 '14 at 01:20
You should post it as an answer. – Barmar Jul 01 '14 at 01:21

ssh2_exec: wait end of a process to run next

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