Moving Fastboot to Userspace

How to change the current active partition slot? fastboot change slot Edit this at Wikidata Google announced the project in July 2009, initially When placed in an HDMI slot on a television set or computer monitor, the fastboot_ error_ failed to identify current slot --slot SLOT Override the default behavior and prompt fastboot to flash the slot that is passed in as an argument --set-active

fastboot get active slot But I want without fastboot command My usecase is the bootloader need to check the currect active slot and set the proper suffix How can I