Creating a temporary file

JavaScript:
Creating a temporary file

How to:

In JavaScript, most temporary file operations lean on external libraries. Here’s a quick example using the tmp library, which you can install with npm install tmp.

const tmp = require('tmp');

// Create a temporary file
tmp.file((err, path, fd, cleanupCallback) => {
  if (err) throw err;

  console.log(`File path: ${path}`);
  // Do things with the file...

  // When you're done, clean it up
  cleanupCallback();
});

Sample output might look like:

File path: /tmp/tmp-9Xp2nVn6hB5W.tmp

Deep Dive

Creating temporary files has a long history in computing, dating back to times when system memory was limited, and intermediate data needed a place to live. In Node.js, the fs module could be used to create temporary files, but it lacks built-in tmp file generation tools.

Using libraries like tmp or tempfile is quite common. They create unique file names, reducing the risk of name clashes and usually handle cleanup themselves. fs.mkdtemp can also be useful for creating a temporary directory for placing multiple tmp files.

Regarding the internals, these libraries typically use the OS’s native mechanisms to create these files securely, often putting them in a system-defined temp directory. On Unix-like systems, this is usually /tmp, while Windows uses something more complex under LocalAppData.

When dealing with temporary files, remember that while they’re “temporary,” improper handling can lead to security vulnerabilities or leftover files cluttering the system.

JavaScript:Creating a temporary file

How to:

Deep Dive

See Also

JavaScript:
Creating a temporary file