Add support for the missing string functions.
Add support for the missing string functions.

cvanlent/tsugi,tsugiproject/tsugi,komizutama/tsugi,csev/tsugi,cvanlent/tsugi,JANQLIANGTSAI/tsugi,komizutama/tsugi,cvanlent/tsugi,komizutama/tsugi,JANQLIANGTSAI/tsugi,tsugiproject/tsugi,reysantos/tsugi,reysantos/tsugi,JANQLIANGTSAI/tsugi,tsugiproject/tsugi,reysantos/tsugi,tsugiproject/tsugi