Node and Javascript: How to Programmatically Access and Cycle Through Files in a Folder

Question

I have a folder with this structure:

folder
  |--file1.csv
  |--file2.csv
  |--file3.csv
  |--file4.csv

Is there a way to programmatically write a script to go into a folder and open one file at a time to do something and then open the next until all files in that folder has been inspected?

One *after* the other or all at the same time? I'm asking cos file operations are asynchronous. — Aron, Mar 20 '17 at 14:36
[node fs](https://nodejs.org/api/fs.html) with [async](https://github.com/caolan/async) — Callum Linington, Mar 20 '17 at 14:37
Have a look at https://nodejs.org/api/fs.html - especially readdir and readdirSync and readfile and readfileSync — x-ray, Mar 20 '17 at 14:38

score 0 · Answer 1 · answered Mar 20 '17 at 14:55

You can use node fs.*Sync() methods which will block until the operation is done.

The readdirSync function will give you a list of files (and subdirectories, which are also files) in a directory and statSync will tell you, if it's a directory or a file.

You should be aware that your script can do nothing else while doing the blocking operations though. So do not export and use that code as a function in a bigger application.

If you want to reuse it, you should write your code in an asynchronous fashion (i.e. use callbacks and handle your state / values accordingly). Or use one of the npm modules that implement the necessary functionality ("walk" seems to be a good search keyword for your use-case).

using Sync methods can be a really bad idea because it doesnt just block the current request on the server, it blocks all the request to the server — Gurbakhshish Singh, Mar 20 '17 at 14:59

Node and Javascript: How to Programmatically Access and Cycle Through Files in a Folder

1 Answers1