Console Helper

Writing one-off scripts or vendor binaries for a package is often problematic:

  • You need to parse arguments manually.
  • You need to send output to the console in a meaningful fashion:
    • Using STDOUT for meaningful, expected output
    • Using STDERR for error messages
    • Ensuring any line breaks are converted to PHP_EOL
    • Optionally, using console colors to provide context, which means:
      • Detecting whether or not the console supports colors in the first place
      • Providing appropriate escape sequences to produce color

Zend\Stdlib\ConsoleHelper helps to address the second major bullet point and all beneath it in a minimal fashion.

Usage

Typical usage is to instantiate a ConsoleHelper, and call one of its methods:

use Zend\Stdlib\ConsoleHelper;

$helper = new ConsoleHelper();
$helper->writeLine('This is output');

You can optionally pass a PHP stream resource to the constructor, which will be used to determine whether or not color support is available:

$helper = new ConsoleHelper($stream);

By default, it assumes STDOUT, and tests against that.

Available methods

ConsoleHelper provides the following methods.

colorize

  • colorize(string $string) : string

colorize() accepts a formatted string, and will then apply ANSI color sequences to them, if color support is detected.

The following sequences are currently supported:

  • <info>...</info> will apply a green color sequence around the provided text.
  • <error>...</error> will apply a red color sequence around the provided text.

You may mix multiple sequences within the same stream.

write

  • write(string $string, bool $colorize = true, resource $stream = STDOUT) : void

Emits the provided $string to the provided $stream (which defaults to STDOUT if not provided). Any EOL sequences are convered to PHP_EOL. If $colorize is true, the string is first passed to colorize() as well.

writeline

  • writeLine(string $string, bool $colorize = true, resource $stream = STDOUT) : void

Same as write(), except it also appends a PHP_EOL sequence to the $string.

writeErrorMessage

  • writeErrorMessage(string $message)

Wraps $message in an <error></error> sequence, and passes it to writeLine(), using STDERR as the $stream.

Example

Below is an example class that accepts an argument list, and determines how and what to emit.

namespace Foo;

use Zend\Stdlib\ConsoleHelper;

class HelloWorld
{
    private $helper;

    public function __construct(ConsoleHelper $helper = null)
    {
        $this->helper = $helper ?: new ConsoleHelper();
    }

    public function __invoke(array $args)
    {
        if (! count($args)) {
            $this->helper->writeErrorMessage('Missing arguments!');
            return;
        }

        if (count($args) > 1) {
            $this->helper->writeErrorMessage('Too many arguments!');
            return;
        }

        $target = array_shift($args);

        $this->helper->writeLine(sprintf(
            '<info>Hello</info> %s',
            $target
        ));
    }
}

When to upgrade

ConsoleHelper is deliberately simple, and assumes that your primary need for console tooling is for output considerations.

If you need to parse complex argument strings, we recommend using zend-console/zf-console or symfony/console, as these packages provide those capabilities, as well as far more colorization and console feature detection facilities.

Found a mistake or want to contribute to the documentation? Edit this page on GitHub!