file_add_form_submit in core/modules/file/file.pages.inc
Submit handler for the add file form.
file_add_upload_step_scheme in core/modules/file/file.pages.inc
Generate form fields for the third step in the add file wizard.
file_field_settings_form in core/modules/file/file.field.inc
Implements hook_field_settings_form().
file_get_stream_wrappers in core/includes/file.inc
Provides Backdrop stream wrapper registry.
file_is_writeable in core/modules/file/file.module
Check if a file entity is considered writeable or not.
file_manage_form in core/modules/file/file.pages.inc
Page callback: Form constructor for the file manage form.
filter_editor_file_upload_settings_form in core/modules/filter/filter.admin.inc
Subform constructor to configure the text editor's file upload settings.
filter_editor_image_upload_settings_form in core/modules/filter/filter.admin.inc
Subform constructor to configure the text editor's image upload settings.
image_field_settings_form in core/modules/image/image.field.inc
Implements hook_field_settings_form().
image_style_flush in core/modules/image/image.module
Flush cached media for a style.
stream_wrappers.inc in core/includes/stream_wrappers.inc
Backdrop stream wrapper interface.
system_file_system_settings in core/modules/system/system.admin.inc
Form builder; Configure the site file handling.