Optimizing images for WordPress with the jpegoptim

jpegoptim.php

<?php

add_filter( 'wp_image_editors', function( $editors ) {
	if ( ! class_exists( '_WP_Image_Editor_GD' ) ) {
		class _WP_Image_Editor_GD extends WP_Image_Editor_GD {
			protected function _save( $image, $filename = null, $mime_type = null ) {
				$saved = parent::_save( $image, $filename, $mime_type );
				if ( ! empty( $saved["mime-type"] ) && 'image/jpeg' == $saved["mime-type"] ) {
					jpegoptim( $saved['path'] );
				}
				return $saved;
			}
		};
	}
	if ( ! class_exists( '_WP_Image_Editor_Imagick' ) ) {
		class _WP_Image_Editor_Imagick extends WP_Image_Editor_Imagick {
			protected function _save( $image, $filename = null, $mime_type = null ) {
				$saved = parent::_save( $image, $filename, $mime_type );
				if ( ! empty( $saved["mime-type"] ) && 'image/jpeg' == $saved["mime-type"] ) {
					jpegoptim( $saved['path'] );
				}
				return $saved;
			}
		};
	}
	return array(
		'_WP_Image_Editor_GD',
		'_WP_Image_Editor_Imagick',
	);
}, 10 );

function jpegoptim( $path, $quality = 60 ) {
	if ( ! is_executable( '/usr/bin/jpegoptim' ) ) {
		trigger_error( '`/usr/bin/jpegoptim` is not executable, please install it.' );
		return;
	}
	if ( is_file( $path ) ) {
		$cmd    = '/usr/bin/jpegoptim -m%d --strip-all %s 2>&1';
		$result = exec( sprintf( $cmd, intval( $quality ), escapeshellarg( $path ) ), $output, $status );
		if ( $status ) {
			trigger_error( $result );
		}
	}
}