React Native

Get a Remote File's Size (32-bit)

Demonstrates the Chilkat SFtp.GetFileSize32 method, which returns a remote file's size in bytes as a 32-bit integer. The arguments are the remote path (or handle), whether symbolic links are followed, and whether the first argument is a handle.

Background: A 32-bit signed integer tops out near 2 GB, so this is fine for ordinary files but will misreport or fail for larger ones. When a file might exceed that, use GetFileSizeStr, which returns the size as a decimal string and cannot overflow. The two boolean arguments are shared by all the attribute getters: the first follows symbolic links to their target, and the second says whether you passed a path or an open handle.

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

async function chilkatExample() {
  // Demonstrates the SFtp.GetFileSize32 method, which returns a remote file's size in bytes as a
  // 32-bit integer.  The 1st argument is the remote path (or handle), the 2nd selects whether
  // symbolic links are followed, and the 3rd indicates whether the 1st argument is a handle.

  const sftp = new SFtp();

  // Connect, authenticate, and initialize the SFTP subsystem.
  const port = 22;
  try {
    await sftp.connectAsync('sftp.example.com', port);
  } catch {
    console.log(sftp.lastErrorText);
    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.
  const password = 'mySshPassword';

  try {
    await sftp.authenticatePwAsync('mySshLogin', password);
  } catch {
    console.log(sftp.lastErrorText);
    return;
  }

  try {
    await sftp.initializeSftpAsync();
  } catch {
    console.log(sftp.lastErrorText);
    return;
  }

  // The 2nd argument (bFollowLinks) selects whether a symbolic link is followed to its target.
  // The 3rd argument (bIsHandle) is false here because the 1st argument is a path, not an
  // open handle.
  const bFollowLinks = true;
  const bIsHandle = false;

  const fileSize = await sftp.getFileSize32Async('subdir/report.pdf', bFollowLinks, bIsHandle);
  if (fileSize < 0) {
    console.log(sftp.lastErrorText);
    return;
  }

  console.log(`File size: ${fileSize} bytes`);

  // Note: For files that may exceed 2 GB, use GetFileSizeStr (returns a decimal string) instead,
  // because the value can overflow a 32-bit integer.

  sftp.disconnect();
}