Objective-C

Send an SSH IGNORE Message

Demonstrates the Chilkat Ssh.SendIgnore method, which sends an SSH IGNORE message. It takes no arguments. The server does not reply, but a successful send helps confirm the connection is still writable. No channel is required.

Background: The SSH IGNORE message is discarded by the peer by design; its usefulness is as a lightweight keep-alive or liveness probe. Because it exercises the actual write path, a successful SendIgnore is stronger evidence than CheckConnection that the link is still usable, without side effects on any channel.

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Objective-C

#import <CkoSsh.h>
#import <NSString.h>

BOOL success = NO;

//  Demonstrates the Ssh.SendIgnore method, which sends an SSH IGNORE message.  It takes no
//  arguments.  The server does not reply, but a successful send helps confirm the connection is
//  still writable.  No channel is required.

CkoSsh *ssh = [[CkoSsh alloc] init];

//  Connect to the SSH server.  Port 22 is the usual SSH port.
int sshPort = 22;
success = [ssh Connect: @"ssh.example.com" port: [NSNumber numberWithInt: sshPort]];
if (success == NO) {
    NSLog(@"%@",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.
NSString *password = @"mySshPassword";

success = [ssh AuthenticatePw: @"mySshLogin" password: password];
if (success == NO) {
    NSLog(@"%@",ssh.LastErrorText);
    return;
}

//  Send an IGNORE message to verify the connection is still writable.
success = [ssh SendIgnore];
if (success == NO) {
    NSLog(@"%@",ssh.LastErrorText);
    return;
}

NSLog(@"%@",@"IGNORE message sent.");

[ssh Disconnect];