title: STRING+
status:
 we recommend to reserve the name STRING+ for the functionality given below.

description:

\ ( addr1 len1 addr2 len2 -- addr1 len3 )
\ append the text specified by addr2 and len2 to the text of length len2
\ in the buffer at addr1. Return address and length of the resulting text.
\ An ambiguous condition exists if the resulting text is larger
\ than the size of buffer at addr1.
: STRING+ ( bufaddr buftextlen addr len -- bufaddr buftextlen+len )
        2OVER +         ( ba btl a l bta+btl )
        SWAP DUP >R     ( ba btl a bta+btl l ) ( r: l )
        MOVE
        R> +
;

see: STRING+C ../string-plus-c/index.html