Getting Started with C# Scripting: A Practical Guide to Automation and Lightweight Development

What is C# Scripting?

C# scripting is a lightweight way to write and run C# code without needing to create a full project in Visual Studio. It’s useful for automation, prototyping, interactive development, and even embedding logic in other environments like Unity or web tools.

How to Get Started (Quick CLI Setup)

  1. Install .NET SDK (if not installed)
    https://dotnet.microsoft.com/en-us/download

  2. Install dotnet-script
    dotnet tool install -g dotnet-script

  3. Create a C# Script File

    // hello.csx
Console.WriteLine("Hello from C# Script!");

  4. Run It
    dotnet script hello.csx
    You’ll see:

    Hello from C# Script!

What Can You Do with C# Scripting?

  • Try snippets quickly

    var now = DateTime.Now.ToString("h:mm:ss tt");
Console.WriteLine($"The time is {now}");

  • Reference packages

    #r "nuget: Newtonsoft.Json, 13.0.3"

using Newtonsoft.Json;

var obj = new { name = "John", age = 30 };
Console.WriteLine(JsonConvert.SerializeObject(obj));

  • Automate tasks
    Script small jobs like:

    • Processing CSV files
    • Web scraping
    • Sending emails
    • File system automation

Use Case: Renaming and Organizing Files in a Folder

Imagine you receive dozens of image or document files daily (e.g., invoices, receipts, etc.), and you want a script that:

  • Renames each file using a timestamp format
  • Moves it to a dated subfolder like ./organized/2025-06-24/

C# Script: organize_files.csx

Create a new file named organize_files.csx in your project folder.

#r "System.IO"

using System;
using System.IO;

// Input directory
var inputDir = "./incoming";

// Output directory base
var outputBaseDir = "./organized";

// Create today's dated folder
var todayFolder = Path.Combine(outputBaseDir, DateTime.Now.ToString("yyyy-MM-dd"));
Directory.CreateDirectory(todayFolder);

Console.WriteLine($"Organizing files from {inputDir} to {todayFolder}...");

// Process each file
foreach (var file in Directory.GetFiles(inputDir))
{
    var ext = Path.GetExtension(file);
    var newFileName = $"file-{DateTime.Now:yyyyMMdd-HHmmssfff}{ext}";
    var destination = Path.Combine(todayFolder, newFileName);

    File.Move(file, destination);
    Console.WriteLine($"Moved: {file} ➜ {destination}");
}

Folder Setup

Before running the script, create these folders:

/incoming      --> Drop your raw files here
/organized     --> The script will auto-create subfolders like /2025-06-24

Running the Script

Run the script using the dotnet-script CLI:

dotnet script organize_files.csx

You should see the log output for each file processed and moved.

What the Script Does

  • Scans all files in /incoming
  • Creates a folder named after today’s date
  • Renames each file using a precise timestamp (e.g., file-20250624-145500123.jpg)
  • Moves the file into the appropriate organized/YYYY-MM-DD folder

Customization Ideas

You can extend the script to:

  • Rename files by prefix (e.g., invoice-..., receipt-...)
  • Only process certain file types (e.g., .pdf, .jpg)
  • Send a daily summary email
  • Schedule this script using Windows Task Scheduler or cron

Benefits of C# Scripting

  • No project files or boilerplate
  • Works cross-platform (Windows, macOS, Linux)
  • Ideal for automation, prototyping, and DevOps tasks
  • Easy to maintain and version-control like any other code

Conclusion

Without the burden of a complete project setup, C# scripting is a strong yet portable tool for handling repetitive file operations, automating tasks, and testing concepts.

The wider potential of scripting in your everyday workflow can be unlocked by beginning with a straightforward use case, such as file organisation. The options increase from this point on: data transformations, report generation, scheduled jobs, and even API integration.

C# scripting is, therefore, a great place to start if you want to increase productivity, decrease manual labour, or simply discover a new way to use C#.

Next Steps:

Want to automate more?

  • Turn this into a scheduled job
  • Add logging to a .txt file
  • Trigger a webhook or send an email after organizing