按字節在NASM彙編解析字符串字節爲32位架構

Question

我是新來組裝，很抱歉，如果這個問題是相當obvious.I正試圖解決爲此我需要通過解析字符串的字符一個彙編程序字符，並對字符進行一些操作並將其存儲在另一個字符串中。所以我的問題是如何在nasm程序集中逐字符地解析字符串。

Answer 1

做這樣的事情：

mov si, <adress of the string in memory> 
    mov cx, <whatever value tells you how long the string is> 
    cld  ; make sure lodsb walks forward, not back (that'd be std then) 
again: 
    lodsb ; get next char to AL and increase SI 
    ; 
    ; <al contains each char of string here, one by one> 
    ; 
    dec cx 
    jnz again ; same as "loop", but not so small