Guided: Build a CLI Password Generator with Go

In this lab, you will create a command-line interface (CLI) password generator using Go. You'll use Go's standard library and CLI interaction to make strong and random passwords based on what the user wants.

There are three files you'll work with: main.go, password.go, and random.go. To finish this lab, you need to understand essential Go language concepts like Go syntax and structure, CLI interaction, randomness in Go, and handling errors.

Before we proceed, it's important to note that you will initially not be able to run the lab as it is. As you progress through and complete various tasks, different components of the lab will start working. Once you've successfully implemented all parts, you'll be able to run the app at any time by clicking the Run button or entering go run . in the Terminal.

Additionally, you will be able to specify certain criteria for password generation using flags in the command prompt:

• To generate a password with a specific length (e.g., 12 characters), use: go run . -l 12

• To exclude uppercase letters from the password, use: go run . -nu

• To exclude lowercase letters from the password, use: go run . -nl

• To exclude numbers from the password, use: go run . -nn

• To exclude special characters from the password, use: go run . -ns

You can combine these flags based on their preferences. For example, to generate a 10-character password excluding lowercase letters and special characters, you can use: go run . -l 10 -nl -ns

These options provide flexibility for you to create passwords tailored to their specific requirements.

First, you will need to import the necessary packages for your main program.

The fmt package, used for formatting input and output is already added in the program. You will need to add the flag package, which is essential for handling command-line arguments. This will allow you to define and parse command-line flags and is crucial for user input. Next, you will define different command-line flags that will allow users to customize their password generation process. By using the flag package, you will be able to define an integer flag for the password length and boolean flags for excluding different character types from the password.

In this step, we will delve into the Generate function in password.go. It accepts parameters like length, includeUpper, includeLower, includeNumbers, and includeSpecial to customize the generated password. The function constructs a charset string based on the included character types. It then builds the password string, ensuring each selected type is represented.

In this step, we look at the random.go file. It has two main functions: StringWithCharset and Shuffle. StringWithCharset makes a random string. It uses the length we want and the characters we give it. Shuffle changes the order of the characters in a string to make it random. These two functions help us create random strings. After finishing all tasks successfully, you can now execute your Go program to generate random passwords. This tool is valuable as it boosts security by producing robust and unpredictable passwords.

You can run the app at any time by clicking the Run button or entering go run . in the Terminal.