_CP_cat is equivalent to the result = string1:string2 BASIC statement.
int _CP_cat(CPSTR** result, CPSTR* string1, CPSTR* string2)
This function returns -1 if an error occurs. The error code is contained in _CP_errno.
CPSTR * s = _CP_mkstr("a");
CPSTR * t = _CP_mkstr("A");
_CP_unix_env();
_CP_cat(&s,s,t);
_CP_TERM(s);
printf("%s\n",_CP_SADDR(s));