framework/console/controllers/FixtureController.php
private function getFixtureRelativeName($fullFixturePath)
    {
        $fixturesPath = FileHelper::normalizePath($this->getFixturePath());
        $fullFixturePath = FileHelper::normalizePath($fullFixturePath);

        $relativeName = substr($fullFixturePath, strlen($fixturesPath) + 1);
        $relativeDir = dirname($relativeName) === '.' ? '' : dirname($relativeName) . DIRECTORY_SEPARATOR;

        return $relativeDir . basename($fullFixturePath, 'Fixture.php');
    }
private function getFixtureRelativeName($fullFixturePath)
    {
        $fixturesPath = FileHelper::normalizePath($this->getFixturePath());
        $fullFixturePath = FileHelper::normalizePath($fullFixturePath);

        $relativeName = substr($fullFixturePath, strlen($fixturesPath) + 1);
        $relativeDir = dirname($relativeName) === '.' ? '' : dirname($relativeName) . DIRECTORY_SEPARATOR;

        return $relativeDir . basename($fullFixturePath, 'Fixture.php');
    }
Calculates fixture's name
Basically, strips [[getFixturePath()]] and `Fixture.php' suffix from fixture's full path.
@see getFixturePath()
@param string $fullFixturePath Full fixture path
@return string Relative fixture name