(Perl) Multiple SendReqExec on Same Connection

Shows how to execute a series of commands on an SSH server and retrieve each command's output (using SendReqExec). Each call to SendReqExec requires its own logical channel. This is not a separate SSH connection -- it's simply a new session channel on the existing SSH connection.

Chilkat Perl Downloads Perl Module for Windows, MacOS, Linux, Alpine Linux, Solaris

use chilkat();

# This example assumes the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

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

# Hostname may be an IP address or domain:
$hostname = "172.16.16.46";
$port = 22;

$success = $ssh->Connect($hostname,$port);
if ($success == 0) {
    print $ssh->lastErrorText() . "\r\n";
    exit;
}

# If receiving output from a command stalls for more than 5 seconds, then stop waiting.
$ssh->put_IdleTimeoutMs(5000);

# Authenticate using login/password:
$success = $ssh->AuthenticatePw("myLogin","myPassword");
if ($success == 0) {
    print $ssh->lastErrorText() . "\r\n";
    exit;
}

# Open a session channel.  (It is possible to have multiple
# session channels open simultaneously.)
$channelNum = $ssh->OpenSessionChannel();
if ($channelNum < 0) {
    print $ssh->lastErrorText() . "\r\n";
    exit;
}

# Request a directory listing on the remote server:
# If your server is Linux/UNIX, change the string from "dir" to "ls"
# Note: Some SSH servers require a CRLF instead of a bare-LF
$cmd = "ls -al\n";
$success = $ssh->SendReqExec($channelNum,$cmd);
if ($success == 0) {
    print $ssh->lastErrorText() . "\r\n";
    exit;
}

# Read whatever output may already be available on the
# SSH connection.  ChannelReadAndPoll returns the number of bytes
# that are available in the channel's internal buffer that
# are ready to be "picked up" by calling GetReceivedText
# or GetReceivedData.
# A return value of -1 indicates failure.
# A return value of -2 indicates a failure via timeout.

# The ChannelReadAndPoll method waits
# for data to arrive on the connection usingi the IdleTimeoutMs
# property setting.  Once the first data arrives, it continues
# reading but instead uses the pollTimeoutMs passed in the 2nd argument:
# A return value of -2 indicates a timeout where no data is received.
$pollTimeoutMs = 2000;
$n = $ssh->ChannelReadAndPoll($channelNum,$pollTimeoutMs);
if ($n < 0) {
    print $ssh->lastErrorText() . "\r\n";
    exit;
}

# Close the channel:
$success = $ssh->ChannelSendClose($channelNum);
if ($success == 0) {
    print $ssh->lastErrorText() . "\r\n";
    exit;
}

# Perhaps we did not receive all of the commands output.
# To make sure,  call ChannelReceiveToClose to accumulate any remaining
# output until the server's corresponding "channel close" is received.
$success = $ssh->ChannelReceiveToClose($channelNum);
if ($success == 0) {
    print $ssh->lastErrorText() . "\r\n";
    exit;
}

# Get the accumulated output of the command:

$cmdOutput = $ssh->getReceivedText($channelNum,"ansi");
if ($ssh->get_LastMethodSuccess() == 0) {
    print $ssh->lastErrorText() . "\r\n";
    exit;
}

# Display the remote shell's command output:
print $cmdOutput . "\r\n";
print "----" . "\r\n";

# -----------------------------------------------------------------
# Now for the 2nd SendReqExe (on the same connection,
# but on a separate logical channel).
# -----------------------------------------------------------------

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

$cmd = "nslookup chilkatsoft.com\n";
$success = $ssh->SendReqExec($channelNum,$cmd);
if ($success == 0) {
    print $ssh->lastErrorText() . "\r\n";
    exit;
}

$pollTimeoutMs = 2000;
$n = $ssh->ChannelReadAndPoll($channelNum,$pollTimeoutMs);
if ($n < 0) {
    print $ssh->lastErrorText() . "\r\n";
    exit;
}

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

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

$cmdOutput = $ssh->getReceivedText($channelNum,"ansi");
if ($ssh->get_LastMethodSuccess() == 0) {
    print $ssh->lastErrorText() . "\r\n";
    exit;
}

print $cmdOutput . "\r\n";