# 🗓️ Expiration check

**Expiration-check** is a command-line tool designed to verify the expiration dates of domains and TLS certificates.

For domain verification, it implements the [RDAP protocol](https://about.rdap.org/) whenever possible. If RDAP is unavailable, it falls back on the WHOIS protocol.

## 📗 How to install the project

Pre-compiled versions are available in the [Releases](https://gitnet.fr/deblan/expiration-check/releases). Multiple operating systems are supported, including Linux, Windows, and macOS. For Debian users, a package is also provided.

If you want to compile the project from source, you will need at least the GO compiler version 1.22. Clone the project and run the make command. The compiled output will be located in the `build` directory.

```
$ git clone https://gitnet.fr/deblan/expiration-check
$ make
```

## 🧪 How to use the project

### Commands

- `certificates`, `certificate`, `cert`, `certs`, `c`: Checks the expiration dates of TLS certificates.
- `domains`, `domain`, `d`: Checks the expiration dates of domain names.
- `help`, `h`: Displays a list of all commands or detailed help for a specific command.

### Global Options

- `--help`, `-h`: Shows the help message, providing information about the usage and available commands.

Use the `--format` or `-f` option to specify the output format. Available formats are table, csv, tsv, html, json, and markdown. The default format is table.

### Examples

Check certificate expirations:

```
expiration-check certificate --domain example.com
```

Check domain expirations:

```
expiration-check domain --domain example.com
```

Check certificates for multiple domains with default table format:

```
expiration-check certificate --domain example.com --domain example.org
```

Check certificates and output results in JSON format:

```
expiration-check certificate --domain example.com --format json
```

Get help for a specific command:

```
expiration-check help certificate
```