diff options
| -rw-r--r-- | string.asm | 59 |
1 files changed, 59 insertions, 0 deletions
@@ -171,4 +171,63 @@ strncmp: ret +strtok: + push bp + mov bp, sp + push bx + push cx + push dx + push di + push si + + xor ax, ax ; clear AX for delimter + xor cx, cx ; initialize string length counter + xor dx, dx ; initialize record counter + sub sp, 2 ; reserve stack variable + ; final_pass = [bp - 2] + + mov di, [bp + 4] ; arg1 - null terminated string + mov si, [bp + 6] ; arg2 - address of results array + mov al, [bp + 8] ; arg3 - delimiter value + cld ; clear direction flag (0) + + jmp .strtok_scan ; begin scan + + .strtok_record_token: + inc dx ; increase record count + mov bx, di ; store address of delimiter + sub bx, cx ; subtract length from address + ; to get start of string + + mov [si], bx ; store start of word + mov [si+2], cx ; store length of word + + add si, 4 ; increment array pointer + xor cx, cx ; reset counter + cmp word [bp - 2], 0 ; is this the final pass? + jne .strtok_return ; if so, return + ; else, fall through + .strtok_scan: + inc cx + scasb ; scan for delimiter in AL + je .strtok_record_token ; if ZF=1, store pointer + cmp byte [di], 0 ; if null terminated, exit loop + jne .strtok_scan ; else continue + + mov word [bp - 2], 1 ; indicate final pass in progress + dec bx ; adjust final address for null termination + jmp .strtok_record_token ; process final address + +.strtok_return: + mov ax, dx ; return record count + pop si + pop di + pop dx + pop cx + pop bx + + mov sp, bp + pop bp + ret + %endif ; _STRING_ASM |