drupal_tempnam in includes/drupal.inc

Creates a file with a unique filename in the specified directory.

file_unmanaged_save_data in includes/file.inc

Saves a file to the specified destination without invoking file API.

image_gd_save in modules/system/image.gd.inc

GD helper to write an image resource to a destination file.

installer_manager_local_transfers_allowed in modules/installer/installer.manager.inc

Determines if file transfers will be performed locally.

LocaleExportFunctionalTest::testExportTranslation in modules/locale/tests/locale.test

Test exportation of translations.

LocaleImportFunctionalTest::importPoFile in modules/locale/tests/locale.test

Helper function: import a standalone .po file in a given language.

LocalePluralFormatTest::importPoFile in modules/locale/tests/locale.test

Imports a standalone .po file in a given language.