passgen/README.md

# passgen

## Table of Contents

- [Introduction](#introduction)
- [Building](#building)
- [Usage](#usage)
- [Options](#options)
- [Examples](#examples)

## Introduction

**passgen** is a password generation tool that allows you to create secure and
customizable passwords. It generates passwords based on user-specified
criteria, including password length and character types (lowercase letters,
uppercase letters, digits, and special characters). You can also use
**passgen** without any options to generate a random password with default
settings.

## Building

This tool is provided as source code and can be built using `make`. By just
typing make in the terminal within the code's directory:

```bash
make
```

You should now have an executable named `passgen`. You can copy it to a location
in your PATH for easy access.

## Usage

To use passgen, open your terminal and execute the program with the desired
options.

```bash
./passgen [OPTIONS]
```

## Options

**passgen** provides the following command-line options:

- `-L`, `--length`:
  - Specify the length of the generated password. Default is 24 characters.
  - Valid range: 5 to 4096 characters.

- `-l`, `--lower-case`:
  - Enable lowercase letters in the password.

- `-u`, `--upper-case`:
  - Enable uppercase letters in the password.

- `-d`, `--digits`:
  - Enable digits in the password.

- `-s`, `--special`:
  - Enable special characters in the password.

- `-h`, `--help`:
  - Display the help message and exit.

- `-v`, `--version`:
  - Display the program version and exit.

## Examples

1. Generate a default password:

    ```bash
    ./passgen
    ```

    This will generate a 24-character password with a mix of lowercase letters,
    uppercase letters, digits, and special characters.

2. Generate a password with specific options:

    ```bash
    ./passgen -L 12 -lud
    ```

    This will generate a 12-character password with only lowercase letters,
    uppercase letters, digits, and no special characters.

3. Display help message:

    ```bash
    passgen -h
    ```

    This will display the usage and available options.

4. Display version:

    ```bash
    passgen -v
    ```
    
    This will display the version of Passgen.