Rust

SSH Exec (Execute Command Line)

Demonstrates running a single command on an SSH server with an exec request and retrieving its output. The example connects, authenticates, opens a session channel, sends the command, reads until the server closes the channel, and then checks the exit status.

Background: exec is the workhorse of SSH automation: it runs one command and the server closes the channel when the command exits, which is a definitive end-of-output signal. No PTY is involved, so the shell runs non-interactively — no prompt, no echoed input, no ANSI escape codes — giving clean, parseable output. Remember that an accepted exec request only means the request was accepted; the command's own success is reported through the channel exit status. Command syntax depends on the remote shell, which is the user's default shell on Linux/UNIX and usually CMD.EXE on Windows SSH servers.

Chilkat Rust Downloads

Download Chilkat for Rust

Rust


// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// Demonstrates running a single command on an SSH server with an exec request and retrieving
// its output.  An exec request runs one command and the server closes the channel when it
// finishes -- no PTY and no shell prompt are involved, so the output is clean and parseable.

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

// The hostname may be a hostname or an IP address.
let hostname = "ssh.example.com".to_string();
let port = 22;
if ssh.connect(&hostname, 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;
}

// Open a session channel.  Several session channels may be open at once on one connection.
let channel_num = ssh.open_session_channel();
if channel_num < 0 {
    println!("{}", ssh.last_error_text());
    return;
}

// The command syntax depends on the remote system's shell.  On Linux/UNIX it is typically the
// user's default shell; on Windows SSH servers it is usually CMD.EXE.
//   Linux/UNIX:  "ls -l /tmp"        or  "cd /etc; ls -la"
//   Windows:     "dir"               or  "\"cd \\temp&&dir\""
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);

// Read the output until the server sends channel close, which happens when the command exits.
if ssh.channel_receive_to_close(channel_num).is_err() {
    println!("{}", ssh.last_error_text());
    return;
}

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

println!("{}", cmd_output);

// An accepted exec request does not mean the command succeeded.  Check the exit status.
if ssh.channel_received_exit_status(channel_num) {
    println!("Exit status: {}", ssh.get_channel_exit_status(channel_num));
}

ssh.disconnect();