/**
* Returns incremental process output (even if empty string) or false if the process has finished
* successfully and all output was already returned.
*
* @throws Symfony_Process_Exception_ProcessFailedException If the process did not exit successfully.
*
* @internal
*
* @return string|false
*/
public function getIncrementalOutput()
{
if (!$this->ran) {
$this->ran = true;
try {
$this->process->start();
} catch (Symfony_Process_Exception_ExceptionInterface $e) {
throw new Symfony_Process_Exception_ProcessFailedException($this->process);
}
}
if ($this->process->isRunning()) {
$output = $this->process->getIncrementalOutput();
$this->process->clearOutput();
if (strlen($output) < Symfony_Process_Pipes_PipesInterface::CHUNK_SIZE) {
// Don't hog the processor while waiting for incremental process output.
usleep(100000);
}
// The stream will be read again because we're returning a string.
return (string) $output;
} else {
if (!$this->process->isSuccessful()) {
throw new Symfony_Process_Exception_ProcessFailedException($this->process);
}
$output = $this->process->getIncrementalOutput();
$this->process->clearOutput();
// The process has finished and is successful. This part will probably get run twice,
// first time we'll return final output, second time we'll return 'false' and break the loop.
return strlen($output) ? $output : false;
}
}
