CLI
, (*1)
CLI is a small library to wrap all the needed informations to build a command line tool. The idea to build this came while reading the ponylang documentation realising that other languages use a similar approach for the entry point of the app, so I decided to have something similar for PHP., (*2)
The said approach is to have a main function as the starting point of execution of your code. This function has a the environment it runs in passed as argument so there's no need for global variables. However since not everything can be passed down as argument (it would complicate the interface), ambient authority can be exercised (as in regular PHP script)., (*3)
Important: to correctly use this library you must validate your code with vimeo/psalm, (*4)
Installation
composer require innmind/cli
Usage
To start a new CLI tool you need this boilerplate code:, (*5)
# cli.php
<?php
declare(strict_types = 1);
require 'path/to/composer/autoload.php';
use Innmind\CLI\{
Main,
Environment,
};
use Innmind\OperatingSystem\OperatingSystem;
new class extends Main {
protected function main(Environment $env, OperatingSystem $os): Environment
{
//your code here
return $env;
}
};
This will directly call the main function. The $env variable gives you access to the 3 standard streams (stdin, stdout, stderr), the list of arguments passed in the cli, all the environment variables, the working directory, if the terminal is interactive and a method to specify the exit code., (*6)
Note: Calling $env->exit(1) will not exit directly your program, you must call return $env->exit(1); in order to make the main function to stop., (*7)
Commands
Using directly the main function is enough when building simple tools, but you often want to provide multiple commands in the same tool (associated with arguments/options validation). This library provides a way to do that. Here's an example:, (*8)
use Innmind\CLI\{
Commands,
Command,
Command\Arguments,
Command\Options,
Console,
};
function main(Environment $env, OperatingSystem $os): void
{
$run = Commands::of(
new class implements Command {
public function __invoke(Console $console): Console
{
//your code here
}
public function usage(): string
{
return 'foo';
}
}
);
return $run($env);
};
In your terminal you would call this command like this php cli.php foo. But since here a single command is defined you could simply call php cli.php. Of course you can define as many commands as you wish., (*9)
Here the command is an anonymous class to simplify the example, but it can be a normal class implementing Command. Since the command simply needs to implement an interface, you have full control of the dependencies you can inject into it. Meaning your commands instances can comme from a dependency injection container. The other advantage since the interface is simple is that you can easily unit test your commands., (*10)
The Command interface requires you to implement 2 methods: __invoke and usage. The first one is the one that will be called if it's the desired command to be called. usage is the place where you define the structure of your command, by that I mean the name of the command, the list of its arguments/options, its short description and full description., (*11)
To define all properties of your command it would ressemble to this:, (*12)
{command name} {optional list of arguments/options}
{short description on a single line}
{full description that can span multiple lines}
Command name and short description are displayed when you run the help command (that will list all available commands). The list of arguments/options and full description are displayed only when you call the command with the extra --help option (or you misused the command)., (*13)
To define arguments you have access to 3 patterns:, (*14)
-
foo with this you ask for a required argument that will be accessed like so $console->arguments()->get('foo')
-
[bar] with this you ask for an optional argument, you must verify its presence via $console->arguments()->contains('bar') before accessing it. Optional arguments can't be followed by required ones
-
...baz with this you ask that all extra arguments will be regrouped as a list with the name baz, it will provide a Sequence<string> of any length. You can only have one argument of this type and must be the last one, you access via $console->arguments()->pack()
To define options you have access to 2 patterns:, (*15)
-
-f|--foo this defines a flag that can be called by -f or --foo, if you don't want a short name simply define --foo
-
-f|--foo= this defines an option that requires a value, if you don't want a short name simply define --foo=. It can be called via -f=value, -f value or --foo=value
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