Ensuring that our command-line tools perform well is an important requirement, especially when designing tools that process a large amount of information, like data analysis tools. But designing tools that perform well isn’t an easy task. Performance is often a subjective concept: it varies from person to person and also according to the context. We’ll define performance as the speed of execution, or how fast our program can handle its workload.

Go provides tools that help us measure and analyze a program’s performance. It has integrated tools for testing, benchmarking, profiling, and tracing.

The CSV format

To explore those tools, we’ll build a CLI application that executes statistical operations on a CSV file. The CSV format consists of tabular data separated by commas. This format is commonly used to store numeric data for statistical and data analysis.

Here’s an example of a CSV file:

IP Address,Timestamp,Response Time,Bytes
192.168.0.199,1520698621,236,3475
192.168.0.88,1520698776,220,3200
192.168.0.199,1520699033,226,3200
192.168.0.100,1520699142,218,3475
192.168.0.199,1520699379,238,3822

We’ll build an initial version of ...

Introduction

First Command-Line Program in Go

Interacting with Users

Working with Files in Go

Navigating the File System

Improving the Performance of CLI Tools

Controlling Processes

Using the Cobra CLI Framework

Talking to REST API

Developing Interactive Terminal Tools

Persisting Data in a SQL Database

Distributing Tool

Appendix

Introduction to colStats

The CSV format