Rust

Receive an SSH Channel Until Close

Demonstrates the Chilkat Ssh.ChannelReceiveToClose method, which receives data on a channel until the server sends and Chilkat processes channel CLOSE. The only argument is the channel number. EOF alone does not complete this method.

Important: Set the ReadTimeoutMs property before calling this method. It defaults to 0, meaning no limit, so without it the call waits forever if the server never sends channel close.

Background: This is the simplest and most reliable way to collect the complete output of a one-shot exec command, because the server closes the channel when the command finishes. It is not appropriate for an interactive shell, which never closes on its own — use the poll-based methods there instead. Both stdout and stderr are processed, merged or kept separate according to StderrToStdout.

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Rust


// Demonstrates the Ssh.ChannelReceiveToClose method, which receives data on a channel until the
// server sends channel CLOSE.  The only argument is the channel number.  EOF alone does not
// complete this method.

let ssh = chilkat::Ssh::new();

let ssh_port = 22;
if ssh.connect("ssh.example.com", ssh_port).is_err() {
    println!("{}", ssh.last_error_text());
    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.
let password = "mySshPassword".to_string();

if ssh.authenticate_pw("mySshLogin", &password).is_err() {
    println!("{}", ssh.last_error_text());
    return;
}

let channel_num = ssh.open_session_channel();
if channel_num < 0 {
    println!("{}", ssh.last_error_text());
    return;
}

if ssh.send_req_exec(channel_num, "ls -l /tmp").is_err() {
    println!("{}", ssh.last_error_text());
    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.set_read_timeout_ms(15000);

// Receive everything the command produces, up to and including channel close.
if ssh.channel_receive_to_close(channel_num).is_err() {
    println!("{}", ssh.last_error_text());
    return;
}

let Ok(output) = ssh.get_received_text(channel_num, "utf-8") else {
    println!("{}", ssh.last_error_text());
    return;
};

println!("{}", output);

ssh.disconnect();