Function getSystemEncoding

packages/core/src/utils/systemEncoding.ts:53–108

()

 * @returns The system encoding as a string, or null if detection fails.
 */
export function getSystemEncoding(): string | null {
  // Windows
  if (os.platform() === 'win32') {
    try {
      const output = execSync('chcp', { encoding: 'utf8' });
      const match = output.match(/:\s*(\d+)/);
      if (match) {
        const codePage = parseInt(match[1], 10);
        if (!isNaN(codePage)) {
          return windowsCodePageToEncoding(codePage);
        }
      }
      // Only warn if we can't parse the output format, not if windowsCodePageToEncoding fails
      throw new Error(
        `Unable to parse Windows code page from 'chcp' output "${output.trim()}". `,
      );
    } catch (error) {
      console.warn(
        `Failed to get Windows code page using 'chcp' command: ${error instanceof Error ? error.message : String(error)}. ` +
          `Will attempt to detect encoding from command output instead.`,
      );
    }
    return null;
  }

  // Unix-like
  // Use environment variables LC_ALL, LC_CTYPE, and LANG to determine the
  // system encoding. However, these environment variables might not always
  // be set or accurate. Handle cases where none of these variables are set.
  const env = process.env;
  let locale = env['LC_ALL'] || env['LC_CTYPE'] || env['LANG'] || '';

  // Fallback to querying the system directly when environment variables are missing
  if (!locale) {
    try {
      locale = execSync('locale charmap', { encoding: 'utf8' })
        .toString()
        .trim();
    } catch (_e) {
      console.warn('Failed to get locale charmap.');
      return null;
    }
  }

  const match = locale.match(/\.(.+)/); // e.g., "en_US.UTF-8"
  if (match && match[1]) {
    return match[1].toLowerCase();
  }

  // Handle cases where locale charmap returns just the encoding name (e.g., "UTF-8")
  if (locale && !locale.includes('.')) {
    return locale.toLowerCase();
  }

  return null;
}

/**