strstr.txt

会变语言实现的一些程序

01  #include <stdio.h>
02  #include <windows.h>
03  
04  int mystrstr(char *addr1, char *addr2)
05  {
06      int m,n;
07      int x;
08      x=strlen(addr1);
09      for (n=0; n<=strlen(addr1); n++)
10      {
11          if (*addr1+n == *addr2)
12          {            
13              for (m=0; m<=strlen(addr2); m++)
14              {
15                  if (*addr1+n+m != *addr2+m)
16                  {
17                      break;
18                  }
19                  if (m == strlen(addr2))
20                  {
21                      return n;
22                  }
23              }            
24          }    
25  
26      }
27  
28      return 0;
29  }
30      int    main()
31        {
32          int num;
33          num = mystrstr("12345678","78");
34          printf("%d",num);
35          return 0;
36        }
37  


strstr proc pszHaystack:PTR BYTE, pszNeedle:PTR BYTE, dwCaseSensitive:DWORD
02      push    esi
03      push    edi
04      xor    eax, eax
05      xor    ecx, ecx
06      xor    edx, edx
07      mov    esi, [pszHaystack]
08      mov    edi, [pszNeedle]
09  @@char:    mov    al, byte ptr [esi]
10      mov    ah, byte ptr [edi]
11      cmp    [dwCaseSensitive], 0
12      jne    @@cmp1
13      cmp    al, "Z"
14      ja    @@cmp0
15      cmp    al, "A"
16      jb    @@cmp0
17      add    al, 32
18  @@cmp0:    cmp    [dwCaseSensitive], 0
19      jne    @@cmp1
20      cmp    ah, "Z"
21      ja    @@cmp1
22      cmp    ah, "A"
23      jb    @@cmp1
24      add    ah, 32
25  @@cmp1:    cmp    al, ah
26      jne    @@next
27      inc    ecx
28      mov    eax, esi
29      inc    edi
30      inc    esi
31      inc    eax
32      cmp    byte ptr [esi], 0
33      je    @@zero
34      cmp    byte ptr [edi], 0
35      je    @@quit
36      jmp    @@char
37  @@zero:    mov    dl, byte ptr [edi]
38      cmp    dl, byte ptr [esi]
39      je    @@quit
40      xor    eax, eax
41      xor    ecx, ecx
42      jmp    @@quit
43  @@next:    mov    edi, [pszNeedle]
44      test    ecx, ecx
45      setz    dl
46      add    esi, edx
47      xor    ecx, ecx
48      xor    eax, eax
49      cmp    byte ptr [esi], 0
50      jne    @@char
51  @@quit:    sub    eax, ecx
52      pop    edi
53      pop    esi
54      ret
55  strstr endp 

;************************************************************
;* lpStrBuff   指向字符串缓冲区                             *
;* lpFindStr   指向要查找的字符串                           *
;* iNumber     要查找的字符串大小                           *
;* 如果函数成功，返回指向查找到的字符串的首指针，否则返回0  *
;************************************************************
StrPos proc uses edi esi ebx lpStrBuff, lpFindStr, iNumber
    mov eax,lpStrBuff
    xor edi,edi
    xor ebx,ebx
    .while BYTE ptr [eax+edi] != NULL
        xor esi,esi
        lea ecx,[eax+edi]
        .while esi < iNumber
            .if BYTE ptr [ecx+esi] == NULL
                xor eax,eax
                ret
            .endif
            mov  edx,lpFindStr
            .if BYTE ptr [edx+esi] == NULL
                xor eax,eax
                ret
            .endif
            movzx edx,BYTE ptr [edx+esi]
            mov ebx,TRUE
            .if BYTE ptr [ecx+esi] != dl
                xor ebx,ebx
                jmp @f
            .endif
            inc esi
        .endw
@@:
        .if ebx
            lea eax,[eax+edi]
            ret
        .endif
        inc edi
    .endw
    xor eax,eax
    ret
StrPos endp