React Native

File Existence Check

See more FTP Examples

Testing to see if a file exists on the FTP server. The GetSizeByName method is a convenient way to check if a file exists. It will return -1 if the file does not exist, otherwise it returns the size of the file in bytes. React Native

import { Ftp2 } from '@chilkat/react-native'

async function chilkatExample() {
  // This example requires the Chilkat API to have been previously unlocked.
  // See Global Unlock Sample for sample code.

  const ftp = new Ftp2();

  ftp.hostname = 'ftp.example.com';
  ftp.username = 'username';
  ftp.password = 'password';

  // Connect and login to the FTP server.
  try {
    await ftp.connectAsync();
  } catch {
    console.log(ftp.lastErrorText);
    return;
  }

  // Set the current remote directory to where the file is located:
  try {
    await ftp.changeRemoteDirAsync('something');
  } catch {
    console.log(ftp.lastErrorText);
    return;
  }

  // Test to see if the file exists by getting the file size by name. 
  // If a -1 is returned, the file does not exist.
  const fileSize = await ftp.getSizeByNameAsync('test123.txt');
  if (fileSize < 0) {
    console.log('file does not exist');
  } else {
    console.log(`file exists and is ${fileSize} bytes in size`);
  }

  await ftp.disconnectAsync();
}