Now, you might ask yourself: “Why would I want to create an anonymous file? What kind of weirdo needs that?” Well, my friend, let me tell you. Anonymous files are perfect for situations where you don’t want anyone else to know about them. They’re like the secret love child of your system nobody knows they exist until you decide to reveal them.

So how do we create these mysterious creatures? It’s actually pretty simple, thanks to our good friend memfd_create(). This function creates a new anonymous file in memory and returns its file descriptor. The beauty of this is that the file doesn’t have a name or any other identifying information it’s completely anonymous!

Here’s an example script for you:

#!/bin/bash

# This script creates an anonymous file in memory using the memfd_create() function.

echo "Creating anonymous file..."

# The memfd_create() function creates a new anonymous file in memory and returns its file descriptor.
# The file descriptor is stored in the variable "fd".
fd=$(memfd_create "anonymous")

echo "File descriptor is $fd"

echo "Writing to anonymous file..." >&$fd

# The above line writes the output of the "echo" command to the anonymous file using the file descriptor.
# The "&" symbol redirects the output to the file descriptor instead of the standard output.
# This allows us to write to the anonymous file without having to specify its name or location.

echo "Done writing!"

echo "Closing anonymous file..."

# The "close" command is used to close the file descriptor and release any resources associated with it.
# In this case, it closes the anonymous file that was created earlier.
close $fd

In this script, we first create an anonymous file using memfd_create(). We then print out the file descriptor so that you can see it. Next, we write some data to the file and finally close it. The file is gone forever (or until you reboot your system).

Now, I know what you’re thinking: “But wait, if this file doesn’t have a name or any other identifying information, how do I access it again?” Well, my friend, that’s the beauty of anonymous files they don’t need to be accessed! They exist solely in memory and are only accessible through their file descriptor.

It might not seem like a big deal at first, but trust me, it can come in handy when you want to keep something hidden from prying eyes (or nosy scripts). Give it a try !