Swift

Check Whether an SSH Exit Status Was Received

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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Swift


func chilkatTest() {
    var success: Bool = 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.

    let ssh = CkoSsh()!

    var sshPort: Int = 22
    success = ssh.connect(hostname: "ssh.example.com", port: sshPort)
    if success == false {
        print("\(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.
    var password: String? = "mySshPassword"

    success = ssh.authenticatePw(login: "mySshLogin", password: password)
    if success == false {
        print("\(ssh.lastErrorText!)")
        return
    }

    var channelNum: Int = ssh.openSessionChannel().intValue
    if channelNum < 0 {
        print("\(ssh.lastErrorText!)")
        return
    }

    success = ssh.sendReqExec(channelNum: channelNum, command: "test -f /etc/hosts")
    if success == false {
        print("\(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.channelReceive(toClose: channelNum)
    if success == false {
        print("\(ssh.lastErrorText!)")
        return
    }

    //  The server is not required to send an exit status for every channel type or command.
    if ssh.channelReceivedExitStatus(channelNum: channelNum) {
        var exitStatus: Int = ssh.getChannelExitStatus(channelNum: channelNum).intValue
        print("Exit status: \(exitStatus)")
    }
    else {
        print("The server did not provide an exit status.")
    }

    ssh.disconnect()

}