Perl

Get Received SSH Text into a StringBuilder

Demonstrates the Chilkat Ssh.GetReceivedSb method, which decodes a channel's receive buffer and appends the text to a StringBuilder. The arguments are the channel number, the charset, and the StringBuilder. The receive buffer is cleared afterward.

Background: Because this appends rather than replaces, it is the natural choice for accumulating output across repeated reads — call it in a loop and the StringBuilder grows into the complete transcript. It also avoids creating a new string on every retrieval, which matters when a command produces a large amount of text.

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Perl

use chilkat();

$success = 0;

#  Demonstrates the Ssh.GetReceivedSb method, which decodes the channel's receive buffer and
#  appends the text to a StringBuilder.  The 1st argument is the channel number, the 2nd is the
#  charset, and the 3rd is the StringBuilder.  The receive buffer is cleared afterward.

$ssh = chilkat::CkSsh->new();

$sshPort = 22;
$success = $ssh->Connect("ssh.example.com",$sshPort);
if ($success == 0) {
    print $ssh->lastErrorText() . "\r\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 == 0) {
    print $ssh->lastErrorText() . "\r\n";
    exit;
}

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

$success = $ssh->SendReqExec($channelNum,"ls -l /tmp");
if ($success == 0) {
    print $ssh->lastErrorText() . "\r\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 == 0) {
    print $ssh->lastErrorText() . "\r\n";
    exit;
}

#  Append the received text to a StringBuilder.  Existing content is preserved.
$sb = chilkat::CkStringBuilder->new();
$success = $ssh->GetReceivedSb($channelNum,"utf-8",$sb);
if ($success == 0) {
    print $ssh->lastErrorText() . "\r\n";
    exit;
}

print "Characters received: " . $sb->get_Length() . "\r\n";
$output = $sb->getAsString();
print $output . "\r\n";

$ssh->Disconnect();