Coder Legion - Recent posts tagged files

How to Configure Nginx as a Proxy Server?

Fri, 01 May 2026 11:10:59 +0000

Hello, I'm Ganesh. I'm building git-lrc, an AI code reviewer that runs on every commit. It is free, unlimited, and source-available on Github. Star Us to help devs discover the project. Do give it a try and share your feedback for improving the product.

In previous article we could able to server simple html page.

Now lets see how to use nginx as a proxy server.

Setting Up a Simple Proxy Server

One of the frequent uses of nginx is setting it up as a proxy server, which means a server that receives requests, passes them to the proxied servers, retrieves responses from them, and sends them to the clients.

We will configure a basic proxy server, which serves requests on behalf of another server running in port 8080.

Here is example of how to configure it.

# This is a comment in the Main Context
worker_processes 1; 

events { 
    # This is a simple directive inside the 'events' context
    worker_connections 1024; 
}

http { 
    # We are now inside the 'http' context

    server { 
        location / {
            proxy_pass http://localhost:8080; # Proxies traffic to the backend on 8080

        }
    }
}

This will be a simple server that listens on the port 8080.

Add Static Files For Existing Proxy Server

let's assume we have a static files in /var/www/html directory and we want to server another application running on port 8080.

so, we can configure both these in nginx it self.

# This is a comment in the Main Context
worker_processes 1; 

events { 
    # This is a simple directive inside the 'events' context
    worker_connections 1024; 
}

http { 
    # We are now inside the 'http' context

    server { 
        location / {
            proxy_pass http://localhost:8080; # Proxies traffic to the backend on 8080

        }

        location /static/ {
            root /var/www/html; # Serves static files from /var/www/html
        }
    }
}

This way we will be able to serve both static files and other server running in port 8080.

Conclusion

We could able to setup simple proxy server and serve both static files and other server running on different port.

Any feedback or contributors are welcome! It’s online, source-available, and ready for anyone to use.
⭐ Star it on GitHub: https://github.com/HexmosTech/git-lrc

How Files Are Stored, Deleted, and Copied Inside Your Computer

Thu, 16 Apr 2026 00:35:04 +0000

How Files Are Stored, Deleted, and Copied Inside Your Computer

Have you ever noticed something interesting?

Deleting a file happens instantly.
Copying a file takes time.
Moving a file is sometimes instant and sometimes slow.

Why does this happen?

If you're new to operating systems and storage internals, this article explains everything in simple terms using real-world analogies, while also giving you a deeper technical understanding of what’s happening behind the scenes.

By the end, you’ll understand:

How files are stored on disk
Why delete is fast
Why copy takes time
Whether files are really deleted
How HDD and SSD behave differently

How Files Are Actually Stored on Disk

Your computer does not store files the way you see them in folders.

Internally, storage is divided into:

Data Blocks (or clusters) – These contain the actual bytes of your file.
Metadata – Information about the file:
- File name
- File size
- Location of data blocks
- Permissions
- Created/modified timestamps

A file system (like NTFS, ext4, FAT32) manages this structure.

Example File Systems

Windows → NTFS
Linux → ext4
USB drives → FAT32

Each filesystem maintains:

A directory entry (file name)
A metadata record (inode in Linux, MFT entry in NTFS)
Pointers to the actual disk blocks

You can think of it like a database that tracks where your file data lives on disk.

Real-Life Analogy: A Library

Imagine this:

The library catalog = filesystem metadata
The books on shelves = actual file data
The shelf location number = pointer to disk blocks

When you open a file:

The system checks the catalog.
It finds the shelf location.
It retrieves the book (data blocks).

Now let’s see what happens during delete and copy.

Why Deleting a File Is Instant

When you delete a file, the system usually does not erase the data immediately.

Instead, it:

Removes the file name from the directory.
Marks its data blocks as “free”.
Updates metadata records.

That’s it.

The actual bytes are still physically on disk — but the system marks that space as available for reuse.

Since this is mainly a metadata update, it happens very fast.

Important Insight

Deleting is like removing the book’s entry from the library catalog.

The book is still on the shelf — but nobody knows it exists anymore.

This is why:

File recovery tools can restore deleted files.
Secure deletion requires special tools.

Do Files Actually Get Deleted?

Short answer: Not immediately.

They are:

Marked as free space
Eventually overwritten by new data

On SSDs:

The operating system sends a TRIM command
The SSD later clears unused blocks internally

Deletion is logical first, physical later.

Why Copying a File Takes Time

Copying is completely different.

When copying:

The system reads every block from the source file.
Loads it into memory (RAM).
Writes those blocks to a new location.
Creates new metadata for the copied file.

This process depends on:

Disk speed
File size
HDD vs SSD
CPU and memory performance

Since the entire file’s data must be read and written, copying takes time.

Example

Copying a 10GB file means:

Reading 10GB
Writing 10GB

That’s 20GB of total I/O operations.

That’s real physical work being done.

Why Moving Files Is Sometimes Instant

This depends on where you move the file.

Case 1: Same Drive (Same Filesystem)

Move = metadata update only.

The system just:

Updates the directory entry
Keeps data blocks unchanged

This is very fast.

Case 2: Different Drive

Move becomes:

Copy the file
Delete the original

So it takes time.

That’s why:

Moving inside C: is instant
Moving from C: to D: takes time

HDD vs SSD Behavior

HDD (Hard Disk Drive)

Mechanical spinning disk
Moving read/write head
Slower seek time
Sequential reads are faster

Copying large files can be slower because of mechanical movement.

SSD (Solid State Drive)

No moving parts
Much faster random access
Uses flash memory cells
Uses TRIM and garbage collection

Deletion marks blocks unused first. The physical erase happens later internally.

What Happens in the OS Layer

At the system-call level (Linux example):

delete → unlink()
copy → multiple read() and write() calls
move (same filesystem) → rename()

Example:

strace rm file.txt

You'll see something like:

unlink("file.txt")

That's simply removing the reference to the file.

Copying involves many read() and write() operations, which take time.

Why Deleting Many Files Can Be Slow

Deleting one file is fast.

Deleting thousands of small files can take time because:

Each file has metadata.
Directory entries must be updated.
Journaling systems must commit changes.

Even metadata operations add up when repeated many times.

Secure Deletion

Normal delete:

Marks space as free

Secure delete:

Overwrites data blocks
Ensures recovery is impossible

On SSDs:

Use drive-level secure erase
Or enable full-disk encryption

Key Takeaways

Delete is fast because it removes metadata, not actual data.
Copy is slow because it transfers real bytes.
Move is fast only within the same filesystem.
Deleted files remain until overwritten.
SSDs and HDDs behave differently.
Secure deletion requires special handling.

What to explore next

File operations look simple from the UI, but under the surface the OS is managing metadata, block allocation, caching, journaling, and hardware coordination.

If this interested you, here are some rabbit holes worth going down:

strace on Linux — run strace rm file.txt or strace cp src dst to see the actual system calls involved
Filesystem internals — look into how ext4 journaling works, or how ZFS and Btrfs use copy-on-write to make snapshots nearly free
Flash Translation Layer — how SSDs remap logical blocks to physical NAND pages, and why TRIM exists
Data recovery tools — tools like testdisk and photorec exploit the fact that "deleted" data is still on disk

The next time a file deletes instantly, you'll know — it wasn't magic. It was just a metadata update.

Introducing SWFT - Simple Web-based File Transfer! ????✨

Mon, 17 Mar 2025 21:39:51 +0000

In today's digital age, file sharing has become an integral part of our daily routines. Whether it's sharing documents for work, sending photos to friends and family, or collaborating on projects, having a reliable and user-friendly file sharing solution is crucial. That's where SWFT - Simple Web-based File Transfer - shines, and the best part? It's open source!

The SWFT Advantage

SWFT is a lightweight and intuitive web-based file sharing service that simplifies the process of sharing files with others. With its impressive set of features, it's poised to become your go-to file sharing solution. Let's take a closer look at what sets SWFT apart:

Seamless File Uploads and Shareable Links

SWFT makes uploading files a breeze. Whether it's a single document or a collection of photos, you can quickly and easily upload your files to the platform. Once uploaded, SWFT generates shareable links that you can send to your recipients. It's a straightforward process that eliminates the need for complex setups or software installations.

Customizable Links for Personalized Sharing

One of SWFT's standout features is its ability to customize shareable links. Instead of sharing long and cryptic URLs, you can assign user-defined names to your links. This personal touch makes sharing files more professional and accessible.

Time-Limited File Sharing

Privacy and security are paramount when sharing files online. SWFT allows you to set a specified time period for file retention. After this duration, your files are automatically deleted. This feature ensures that your shared files have a limited lifespan, adding an extra layer of security and privacy to your file sharing.

Support for Command-Line Users

SWFT caters to all types of users, including those who prefer command-line tools like curl or wget. This versatility means that tech-savvy individuals can seamlessly integrate SWFT into their workflow. Here's an example command using curl to upload a file and customize your shareable link:

curl -X POST -F "file=@path/to/your/file" -F "link=my-custom-link" -F "time=1800" https://share.nnisarg.in/upload

Simply replace path/to/your/file with the actual path to your file, my-custom-link with your preferred link name and 1800 with the desired time period in seconds. This command allows you to harness the power of SWFT directly from the command line, making file sharing a breeze for tech-savvy users.

How to Get Started with SWFT

Getting started with SWFT is as easy as 1-2-3:

Visit the SWFT website.
Upload your files and customize your shareable link and delete time if desired.
Share the link with your intended recipients.

It's that simple! SWFT streamlines the file sharing process, making it accessible to users of all levels of tech proficiency.

Get Involved on GitHub

Ready to get involved with SWFT? Visit our GitHub repository at SWFT on GitHub. Here, you can:

Fork the project: Create your own copy of SWFT and start making changes.
Report issues: If you encounter a bug or have a feature request, let us know by creating an issue on GitHub.
Contribute code: If you're a developer, you can contribute directly to the project by submitting pull requests.
Join the community: Connect with other SWFT users and developers to share ideas and collaborate.

Join the SWFT Community Today

Whether you're a casual user or a seasoned developer, SWFT welcomes you to join our open source community. Together, we can create a file sharing solution that meets the needs of users worldwide. Visit our GitHub repository, explore the code, and start sharing files effortlessly with SWFT today! Your files, your way, with SWFT!