#filesyste

Node.js provides the fs module, which allows you to interact with the file system. The module allows you to create, read , and modify files. However, the module can do a lot more than just read and write files, for example you can do the following : 

Verify Path Exist

fs.exists(path, callback)

fs.existsSync(path)

          Both function return true or false

fs.exists('grano-StreamWrites.txt', function(res) { console.log(res ? "Path is there" : "Path is not there"); });

Get File Information 

fs.stat(path, callback)

fs.statSync(path)

Both function return a Stats object (http://nodejs.org/api/fs.html#fs_class_fs_stats)

fs.stat('grano-StreamWrites.txt',function(err, res) { if(!err){ console.log('stats : ' + JSON.stringify(res, null, ' ')); res.isDirectory(); res.isBlockDevice(); res.isFIFO(); } });

List Files in Directory

fs.readdir(path, callback)

fs.readdirSync(path, callback)

var path = require('path'); function viewDir (dirPath) { console.log (' Directory Path = > ' + dirPath); fs.readdir(dirPath,function(err , res) { for (var idx in res){ var fullPath = path.join(dirPath, res[idx]); (function(fullPath) { fs.stat(fullPath,function(err, stats) { if (stats && stats.isFile()) { console.log(fullPath); } else if (stats && stats.isDirectory()){ viewDir(fullPath); } }); })(fullPath); } }); } viewDir("/Users/username/Documents/");

Delete Files

fs.unlink(path, callback)

fs.unlinkSync(path)

          Both function return true or false

fs.unlink("filename.txt", function(err) { console.log( err ? "File Deleted Failed" : "File Deleted "); });

Truncating Files

      This option is very useful for temp logs files

fs.truncate(path, len, callback)

fs.truncateSync(path, len)

          Both function return true or false

fs.truncate('file.txt', function(err) { console.log(err ? "File Was not Truncated" : "File was truncated"); });

Create Folders 

fs.mkdir(path , callback) 

fs.mkdirSync(path)

fs.mkdir("./Folder1", function(err) { if(!err){ fs.mkdir("./Folder1/Folder2",function(err) { if (!err) {console.log("Folder Created")}; }); } });

      Note: remember that the fs.mkdir is an asynchronous method so we need to wait for the call back in order to create a subfolder

Delete Folder 

fs.rmdir(path, callback)

fs.rmdirSync(path)

fs.rmdir("./Folder1/Folder2", function(err) { if(!err){ fs.rmdir("./Folder1",function(err) { if (!err) {console.log("Folder Deleted Created")}; }); } });

Renaming Files and Dir 

fs.rename (old_path,new_path, callback)

fs.renameSync (old_path, new_path)