Phar file stub
Tar-based phars
What makes a phar a phar and not a tar or a zip?
PHP Manual

## Head-to-head comparison of Phar, Tar and Zip

What are the good and the bad things about the three supported file formats in the phar extension? This table attempts to address that question.

Feature matrix: Phar vs. Tar vs. Zip
Feature | Phar | Tar | Zip
--- | --- | --- | ---
Standard File Format | No | Yes | Yes
Can be executed without the Phar Extension [1] | Yes | No | No
Per-file compression | Yes | No | Yes
Whole-archive compression | Yes | Yes | No
Whole-archive signature validation | Yes | Yes | No
Web-specific application support | Yes | Yes | Yes
Per-file Meta-data | Yes | Yes | Yes
Whole-Archive Meta-data | Yes | Yes | Yes
Archive creation/modification [2] | Yes | Yes | Yes
Full support for all stream wrapper functions | Yes | Yes | Yes
Can be created/modified even if phar.readonly=1 [3] | No | Yes | Yes

Tip

[1] PHP can only directly access the contents of a Phar archive without the Phar extension if it is using a stub that extracts the contents of the phar archive. The stub created by Phar::createDefaultStub() extracts the phar archive and runs its contents from a temporary directory if no phar extension is found.

Tip

[2] All write access requires phar.readonly to be disabled in php.ini or on the command-line directly.

Tip

[3] Only tar and zip archives without .phar in their filename and without an executable stub .phar/stub.php can be created if phar.readonly=1.

Phar file stub
Tar-based phars
What makes a phar a phar and not a tar or a zip?
PHP Manual