strutils.cpp

#ifdef _WIN32
    __asm
    {
        mov ah, 'A'
        mov dh, 'Z'

        mov esi, str1
        mov ecx, str2
        mov dl, [ecx]
        test dl,dl ; NULL?
        jz short str2empty_label

outerloop_label:
        mov ebx, esi ; save esi
        inc ebx
innerloop_label:
        mov al, [esi]
        inc esi
        test al,al
        je short str2notfound_label ; not found!

        cmp     dl,ah           ; 'A'
        jb      short skip1
        cmp     dl,dh           ; 'Z'
        ja      short skip1
        add     dl,'a' - 'A'    ; make lowercase the current character in str2
skip1:

        cmp     al,ah           ; 'A'
        jb      short skip2
        cmp     al,dh           ; 'Z'
        ja      short skip2
        add     al,'a' - 'A'    ; make lowercase the current character in str1
skip2:

        cmp al,dl
        je short onecharfound_label
        mov esi, ebx ; restore esi value, +1
        mov ecx, str2 ; restore ecx value as well
        mov dl, [ecx]
        jmp short outerloop_label ; search from start of str2 again
onecharfound_label:
        inc ecx
        mov dl,[ecx]
        test dl,dl
        jnz short innerloop_label
        jmp short str2found_label ; found!
str2empty_label:
        mov eax, esi // empty str2 ==> return str1
        jmp short ret_label
str2found_label:
        dec ebx
        mov eax, ebx // str2 found ==> return occurence within str1
        jmp short ret_label
str2notfound_label:
        xor eax, eax // str2 nt found ==> return NULL
        jmp short ret_label
ret_label:
    }
#endif
#ifdef _WIN64

#endif // _WIN64