Check Whether an SSH Exit Status Was Received

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Demonstrates the Chilkat Ssh.ChannelReceivedExitStatus method, which reports whether the server supplied an exit-status value for a channel. The only argument is the channel number. When it returns true, call GetChannelExitStatus to read the value.

Background: Always test this before reading the exit status, because the server is not required to send one for every channel type or command — treating a missing status as "0" would silently turn a failure into a success. Exit status is independent of EOF and CLOSE: it can arrive after EOF and either before or together with CLOSE.

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bool success = false;

//  Demonstrates the Ssh.ChannelReceivedExitStatus method, which reports whether the server
//  supplied an exit-status value for a channel.  The only argument is the channel number.  When
//  it returns true, call GetChannelExitStatus to read the value.

Chilkat.Ssh ssh = new Chilkat.Ssh();

int sshPort = 22;
success = ssh.Connect("ssh.example.com",sshPort);
if (success == false) {
    Debug.WriteLine(ssh.LastErrorText);
    return;
}

//  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.
string password = "mySshPassword";

success = ssh.AuthenticatePw("mySshLogin",password);
if (success == false) {
    Debug.WriteLine(ssh.LastErrorText);
    return;
}

int channelNum = ssh.OpenSessionChannel();
if (channelNum < 0) {
    Debug.WriteLine(ssh.LastErrorText);
    return;
}

success = ssh.SendReqExec(channelNum,"test -f /etc/hosts");
if (success == false) {
    Debug.WriteLine(ssh.LastErrorText);
    return;
}

//  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;

success = ssh.ChannelReceiveToClose(channelNum);
if (success == false) {
    Debug.WriteLine(ssh.LastErrorText);
    return;
}

//  The server is not required to send an exit status for every channel type or command.
if (ssh.ChannelReceivedExitStatus(channelNum)) {
    int exitStatus = ssh.GetChannelExitStatus(channelNum);
    Debug.WriteLine("Exit status: " + Convert.ToString(exitStatus));
}
else {
    Debug.WriteLine("The server did not provide an exit status.");
}

ssh.Disconnect();