backdrop_requirements_url in core/includes/install.inc
Returns a URL for proceeding to the next page after a requirements problem.
ckeditor_requirements in core/modules/ckeditor/ckeditor.install
Implements hook_requirements().
image_requirements in core/modules/image/image.install
Implements hook_requirements() to check the PHP GD Library.
install_verify_requirements in core/includes/install.core.inc
Verifies the requirements for installing Backdrop.
system_requirements in core/modules/system/system.install
Implements hook_requirements().
theme_status_report in core/modules/system/system.theme.inc
Returns HTML for the status report.
unicode_requirements in core/includes/unicode.inc
Returns Unicode library status and errors.
UpdateScriptFunctionalTest::testRequirements in core/modules/system/tests/system.test
Tests that requirements warnings and errors are correctly displayed.
update_check_requirements in core/update.php
Checks update requirements and reports errors and (optionally) warnings.
update_init in core/modules/update/update.module
Implements hook_init().
update_script_test_requirements in core/modules/simpletest/tests/update_script_test.install
Implements hook_requirements().
_update_requirement_check in core/modules/update/update.install
Fills in the requirements array.