SSH to a Cisco Switch - Processing "More" Responses

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Demonstrates connecting to a Cisco switch, entering privileged mode with the ena command, and running a command whose response is paged. Each page ends with --More-- and requires a SPACE character to request the next page.

Note: QuickShell allocates a PTY, which is what a network device console expects. The device presents an interactive prompt, and each command's output is read up to the next prompt.

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

// Demonstrates connecting to a Cisco switch, entering privileged mode, and running a command
// whose response is paged -- each page ends with "--More--" and requires a SPACE character to
// request the next page.

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

let port = 22;
if ssh.connect("172.16.16.100", 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.quick_shell();
if channel_num < 0 {
    println!("{}", ssh.last_error_text());
    return;
}

// IMPORTANT: Set a read timeout before receiving until a match.  ReadTimeoutMs defaults to 0,
// which means no limit -- without it, this call waits forever if the received data never
// contains a match.
ssh.set_read_timeout_ms(15000);

let case_sensitive = true;

// In unprivileged mode the switch prompt ends with ">".
if ssh.channel_receive_until_match(channel_num, ">", "utf-8", case_sensitive).is_err() {
    println!("{}", ssh.last_error_text());
    return;
}

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

println!("{}", received);

// Send "ena" to enter privileged mode.  Cisco devices expect a bare CR to terminate a command.
if ssh.channel_send_string(channel_num, "ena\r", "utf-8").is_err() {
    println!("{}", ssh.last_error_text());
    return;
}

if ssh.channel_receive_until_match(channel_num, "Password:", "utf-8", case_sensitive).is_err() {
    println!("{}", ssh.last_error_text());
    return;
}

received = ssh.get_received_text(channel_num, "utf-8").unwrap_or_default();
if !ssh.last_method_success() {
    println!("{}", ssh.last_error_text());
    return;
}

println!("{}", received);

// The enable password is separate from the login password, and likewise should come from a
// secure source rather than being hard-coded.
let enable_password = "myEnablePassword".to_string();
if ssh.channel_send_string(channel_num, &enable_password, "utf-8").is_err() {
    println!("{}", ssh.last_error_text());
    return;
}

if ssh.channel_send_string(channel_num, "\r", "utf-8").is_err() {
    println!("{}", ssh.last_error_text());
    return;
}

// In privileged mode the prompt ends with "#" instead of ">".
if ssh.channel_receive_until_match(channel_num, "#", "utf-8", case_sensitive).is_err() {
    println!("{}", ssh.last_error_text());
    return;
}

received = ssh.get_received_text(channel_num, "utf-8").unwrap_or_default();
if !ssh.last_method_success() {
    println!("{}", ssh.last_error_text());
    return;
}

println!("{}", received);

// Run a command whose output is delivered a page at a time.
if ssh.channel_send_string(channel_num, "show running-config\r", "utf-8").is_err() {
    println!("{}", ssh.last_error_text());
    return;
}

// Each read ends either at the device prompt (output complete) or at "--More--" (another page
// is waiting).  Match the full prompt rather than a bare "#", because "#" also appears inside
// configuration text and would match too early.
let sa_match = chilkat::StringArray::new();
let _ = sa_match.append("MySwitchName#");
let _ = sa_match.append("--More--");

let sb_received = chilkat::StringBuilder::new();
let mut more_coming = true;

while more_coming {
    if ssh.channel_receive_until_match_n(channel_num, &sa_match, "utf-8", case_sensitive).is_err() {
        println!("{}", ssh.last_error_text());
        return;
    }

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

    let _ = sb_received.append(&page_text);
    println!("{}", page_text);

    // If this page ended with "--More--", send a SPACE to request the next page.
    more_coming = sb_received.contains("--More--", case_sensitive);
    if more_coming {
        if ssh.channel_send_string(channel_num, " ", "utf-8").is_err() {
            println!("{}", ssh.last_error_text());
            return;
        }

    }

}

ssh.disconnect();