See the \Magento\Shipping\Model\Shipping\LabelGenerator::createPdfPageFromImageString()
method as a real usage example:
Step 1
Getting a temporary directory writer:
Step 2
Creating a temporary directory, if it is absent.
In most of the case this step is not needed because if you write a file with the Magento 2 methods then the directory will be created automatically.
But the \Magento\Shipping\Model\Shipping\LabelGenerator::createPdfPageFromImageString()
method writes a file in non-standard way by using the imagepng
function which does not created the file path automatically.
Step 3
Write a file. This is a non-standard way:
The standard way is described in the article How to write a file programmatically.
Step 4
Deleting the temporary file: