Rust

Check Whether the Last SFTP Read Failed

Demonstrates the Chilkat SFtp.LastReadFailed method, which returns whether the most recent read for a handle failed. The only argument is the handle. A normal end-of-file is not a failure.

Background: A chunked read loop needs to tell three outcomes apart: more data, a clean end-of-file, and an actual error such as a dropped connection or a revoked handle. LastReadFailed isolates the error case — it is false on a normal EOF read (which succeeds with zero bytes) and true for an empty, malformed, or already-closed handle — so the loop can stop cleanly on EOF but bail out with an error message on a genuine failure.

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Rust


// Demonstrates the SFtp.LastReadFailed method, which returns whether the most recent read for a
// handle failed.  The only argument is the handle.  A normal end-of-file is NOT a failure.

let sftp = chilkat::SFtp::new();

// Connect, authenticate, and initialize the SFTP subsystem.
let port = 22;
if sftp.connect("sftp.example.com", port).is_err() {
    println!("{}", sftp.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 sftp.authenticate_pw("mySshLogin", &password).is_err() {
    println!("{}", sftp.last_error_text());
    return;
}

if sftp.initialize_sftp().is_err() {
    println!("{}", sftp.last_error_text());
    return;
}

let Ok(handle) = sftp.open_file("subdir/data.txt", "readOnly", "openExisting") else {
    println!("{}", sftp.last_error_text());
    return;
};

let mut reading = true;
let chunk_size = 4096;
let bd = chilkat::BinData::new();
while reading {
    let _ = sftp.read_file_bd(&handle, chunk_size, &bd).is_ok();

    // Distinguish an actual read failure from a normal EOF.  On EOF the read succeeds, returns
    // zero bytes, and LastReadFailed is false.
    if sftp.last_read_failed(&handle) {
        println!("Read failed: {}", sftp.last_error_text());
        return;
    }

    reading = !sftp.eof(&handle);
}

if sftp.close_handle(&handle).is_err() {
    println!("{}", sftp.last_error_text());
    return;
}

println!("Read {} bytes with no read failures.", bd.num_bytes());

sftp.disconnect();