Q1. How do you get file statistics in Node.js?
Use fs.stat(), fs.lstat() (for symbolic links), or fs.fstat() (with file descriptor). Example:
fs.stat('file.txt', (err, stats) => { if (err) throw err; console.log(stats); });Q2. What information does the Stats object provide?
The Stats object provides: .size (file size in bytes), .atime (last access time), .mtime (last modification time), .ctime (creation/change time), .birthtime (birth time), .mode (permissions), .uid/.gid (owner/group IDs). Also methods like .isFile(), .isDirectory(), .isSymbolicLink(), .isSocket(), etc.
Q3. How do you check if a path is a file or directory?
After getting stats, use .isFile() and .isDirectory(). Example:
fs.stat('path', (err, stats) => { if (stats.isFile()) console.log('File'); else if (stats.isDirectory()) console.log('Directory'); });Q4. How do you get file permissions?
File permissions are in stats.mode. You can extract them using bitmasks. Example:
const mode = stats.mode & 0o777;fs.access('file', fs.constants.R_OK, (err) => { console.log(err ? 'not readable' : 'readable') });Q5. What's the difference between stat, lstat, and fstat?
fs.stat() follows symbolic links - it returns stats of the target. fs.lstat() works on the symbolic link itself, not its target. fs.fstat() takes a file descriptor (from fs.open()) and returns stats for that open file. Choose based on whether you need info about the link or the target.