cuniq

cuniq (from column-uniq) is a simple, blazing-fast command-line utility for counting the occurrences of unique values in a specific CSV column.

It's a specialized replacement for common shell pipelines like cut | sort | uniq -c. cuniq is often much faster, finds the column by its header name (not its index), and is built in Rust for performance and memory safety.

🚀 Features

• Fast: Written in Rust, it processes files much faster than many scripted equivalents.
• Header-Aware: You specify the column by its name (e.g., user_id), not its position (e.g., f-2). This makes your scripts more robust to changes in the CSV structure.
• Simple: Follows the GNU utility philosophy. It does one thing and does it well.
• Flexible: Output to standard out (stdout) or to a new file.

⚙️ Usage

The basic command structure is:

cuniq --column <COLUMN_NAME> --input <INPUT_FILE> [OPTIONS]

Examples

Let's say you have a file named access_logs.csv:

timestamp,ip_address,http_method,status_code,user_agent
2025-10-28,192.168.1.1,GET,200,"Mozilla..."
2025-10-28,10.0.0.5,GET,200,"Chrome..."
2025-10-28,192.168.1.1,POST,404,"Mozilla..."
2025-10-28,10.0.0.8,GET,200,"Chrome..."
2025-10-28,10.0.0.5,POST,201,"Chrome..."
2025-10-28,192.168.1.1,GET,200,"Mozilla..."

---

1. Count values and print to terminal

To count the occurrences of each status_code:

$ cuniq --column status_code --input access_logs.csv

status_code,count
200,4
404,1
201,1

---

2. Count values and save to a new file

To count the occurrences of each ip_address and save the result:

$ cuniq -c ip_address -i access_logs.csv -o ip_counts.csv

The new file ip_counts.csv will contain:

ip_address,count
192.168.1.1,3
10.0.0.5,2
10.0.0.8,1

---

CLI Options

Usage: cuniq --column <COLUMN_NAME> --input <FILE_PATH> [OPTIONS]

Options:
  -c, --column <COLUMN_NAME>
          Column name to count (case-sensitive)
  -i, --input <FILE_PATH>
          Path to the input CSV file
  -o, --output <OUTPUT_PATH>
          Path to output file (optional). If not provided, results are printed to stdout
  -h, --help
          Print help
  -V, --version
          Print version

📜 License

This project is licensed under the MIT License.