Function headFile

src/filesystem/lib.ts:337–372

(filePath: string, numLines: number)

// New function to get the first N lines of a file
export async function headFile(filePath: string, numLines: number): Promise<string> {
  const fileHandle = await fs.open(filePath, 'r');
  try {
    const lines: string[] = [];
    let buffer = '';
    let bytesRead = 0;
    const chunk = Buffer.alloc(1024); // 1KB buffer
    
    // Read chunks and count lines until we have enough or reach EOF
    while (lines.length < numLines) {
      const result = await fileHandle.read(chunk, 0, chunk.length, bytesRead);
      if (result.bytesRead === 0) break; // End of file
      bytesRead += result.bytesRead;
      buffer += chunk.slice(0, result.bytesRead).toString('utf-8');
      
      const newLineIndex = buffer.lastIndexOf('\n');
      if (newLineIndex !== -1) {
        const completeLines = buffer.slice(0, newLineIndex).split('\n');
        buffer = buffer.slice(newLineIndex + 1);
        for (const line of completeLines) {
          lines.push(line);
          if (lines.length >= numLines) break;
        }
      }
    }
    
    // If there is leftover content and we still need lines, add it
    if (buffer.length > 0 && lines.length < numLines) {
      lines.push(buffer);
    }
    
    return lines.join('\n');
  } finally {
    await fileHandle.close();
  }
}

export async function searchFilesWithValidation(
  rootPath: string,