PHP Extension

Get Text Received on an SSH Channel

Demonstrates the Chilkat Ssh.GetReceivedText method, which decodes and returns all text currently accumulated in a channel's normal receive buffer. The first argument is the channel number and the second is the charset. The receive buffer is cleared after the text is returned.

Background: This is the retrieval half of the read-then-get pattern: a Channel* read or receive call fills the buffer, and this hands you the text. Because the buffer is cleared on retrieval, each call returns only what arrived since the last one. A valid channel with nothing buffered returns an empty string successfully, so an empty result is not an error. Retrieve text promptly after a channel completes, before other SSH operations can discard the completed channel record.

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PHP Extension

<?php

include("chilkat.php");

$success = false;

//  Demonstrates the Ssh.GetReceivedText method, which decodes and returns all text currently in
//  a channel's normal receive buffer.  The 1st argument is the channel number and the 2nd is the
//  charset.  The receive buffer is cleared after the text is returned.

$ssh = new CkSsh();

$sshPort = 22;
$success = $ssh->Connect('ssh.example.com',$sshPort);
if ($success == false) {
    print $ssh->lastErrorText() . "\n";
    exit;
}

//  Normally you would not hard-code the password in source.  You should instead obtain it
//  from an interactive prompt, environment variable, or a secrets vault.
$password = 'mySshPassword';

$success = $ssh->AuthenticatePw('mySshLogin',$password);
if ($success == false) {
    print $ssh->lastErrorText() . "\n";
    exit;
}

$channelNum = $ssh->OpenSessionChannel();
if ($channelNum < 0) {
    print $ssh->lastErrorText() . "\n";
    exit;
}

$success = $ssh->SendReqExec($channelNum,'cat /etc/hostname');
if ($success == false) {
    print $ssh->lastErrorText() . "\n";
    exit;
}

//  IMPORTANT: Set a read timeout.  ReadTimeoutMs defaults to 0, which means no limit -- without
//  it, this call waits forever if the server never sends channel close.
$ssh->put_ReadTimeoutMs(15000);

$success = $ssh->ChannelReceiveToClose($channelNum);
if ($success == false) {
    print $ssh->lastErrorText() . "\n";
    exit;
}

//  Retrieve the accumulated output.  A valid channel with no buffered data returns an empty
//  string successfully.
$output = $ssh->getReceivedText($channelNum,'utf-8');
if ($ssh->get_LastMethodSuccess() == false) {
    print $ssh->lastErrorText() . "\n";
    exit;
}

print $output . "\n";

$ssh->Disconnect();

?>