7 functions implement hook_requirements()

Note: the procedural functions in this list are found by pattern matching, so the list may include some functions that are not actually implementations of this hook.

install_check_class_requirements in core/includes/install.inc

Checks a module or profile requirements.

install_check_requirements in core/includes/install.core.inc

Checks installation requirements and reports any errors.

install_display_requirements in core/includes/install.core.inc

Displays installation requirements.

install_verify_requirements in core/includes/install.core.inc

Verifies the requirements for installing Drupal.

requirements1_test_requirements in core/modules/system/tests/modules/requirements1_test/requirements1_test.install

Implements hook_requirements().

update_check_requirements in core/includes/update.inc

Checks update requirements and reports errors and (optionally) warnings.

update_system_schema_requirements in core/includes/update.inc

Returns whether the minimum schema requirement has been satisfied.