get_temp_dir()

get_temp_dir() — Determines a writable directory for temporary files. Function’s preference is the return value of sys_get_temp_dir(), followed by the upload_tmp_dir value from php.ini, followed by WP_CONTENT_DIR, before finally defaulting to /tmp/. Note that sys_get_temp_dir() honors the TMPDIR environment variable. In the event that this function does not find a writable location, it may be overridden by the WP_TEMP_DIR constant in your wp-config.php file.

Returns string: Writable temporary directory.