PHP

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

use Chilkat2\Ssh;

// 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 Ssh();

$sshPort = 22;
try {
    $ssh->Connect('ssh.example.com', $sshPort);

    // 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';

    $ssh->AuthenticatePw('mySshLogin', $password);
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

$channelNum = $ssh->OpenSessionChannel();
if ($channelNum < 0) {
    echo $ssh->LastErrorText, "\n";
    exit;
}

try {
    $ssh->SendReqExec($channelNum, 'cat /etc/hostname');

    // 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->ReadTimeoutMs = 15000;

    $ssh->ChannelReceiveToClose($channelNum);

    // Retrieve the accumulated output.  A valid channel with no buffered data returns an empty
    // string successfully.
    $output = $ssh->GetReceivedText($channelNum, 'utf-8');
} catch (\Chilkat2\Exception $e) {
    echo $e->getMessage(), "\n";
    exit;
}

echo $output, "\n";

$ssh->Disconnect();