Get the Exit Status of a Remote SSH Command

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Demonstrates the Chilkat Ssh.GetChannelExitStatus method, which returns the remote process exit status for a channel. The only argument is the channel number. Call it only after ChannelReceivedExitStatus returns true.

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

BOOL success = NO;

//  Demonstrates the Ssh.GetChannelExitStatus method, which returns the remote process exit
//  status for a channel.  The only argument is the channel number.  Call it only after
//  ChannelReceivedExitStatus returns true.

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

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;
}

int channelNum = [[ssh OpenSessionChannel] intValue];
if (channelNum < 0) {
    NSLog(@"%@",ssh.LastErrorText);
    return;
}

success = [ssh SendReqExec: [NSNumber numberWithInt: channelNum] command: @"grep -q root /etc/passwd"];
if (success == NO) {
    NSLog(@"%@",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 = [NSNumber numberWithInt:15000];

success = [ssh ChannelReceiveToClose: [NSNumber numberWithInt: channelNum]];
if (success == NO) {
    NSLog(@"%@",ssh.LastErrorText);
    return;
}

//  Retrieve the exit status immediately, before calling unrelated SSH methods or releasing the
//  channel, because the completed channel record can be discarded.
if ([ssh ChannelReceivedExitStatus: [NSNumber numberWithInt: channelNum]]) {
    int exitStatus = [[ssh GetChannelExitStatus: [NSNumber numberWithInt: channelNum]] intValue];
    NSLog(@"%@%d",@"Exit status: ",exitStatus);

    //  By convention, 0 means the remote command succeeded.
    if (exitStatus == 0) {
        NSLog(@"%@",@"The remote command succeeded.");
    }
    else {
        NSLog(@"%@",@"The remote command reported a failure.");
    }

}

[ssh Disconnect];