stricmp和_stricmp

向右看齐 2022-07-14 05:59 110阅读 0赞

在msdn里面（[http://msdn.microsoft.com/en-us/library/ms235365(VS.80).aspx][http_msdn.microsoft.com_en-us_library_ms235365_VS.80_.aspx]）有这么一段话：

These POSIX functions are deprecated beginning in Visual C++ 2005. Use the ISO C++ conformant[\_stricmp, \_wcsicmp, \_mbsicmp, \_stricmp\_l, \_wcsicmp\_l, \_mbsicmp\_l][stricmp_ _wcsicmp_ _mbsicmp_ _stricmp_l_ _wcsicmp_l_ _mbsicmp_l] instead.

意思是在Visual C++ 2005以后，stricmp, wcsicmp被[\_stricmp, \_wcsicmp, \_mbsicmp, \_stricmp\_l, \_wcsicmp\_l, \_mbsicmp\_l][stricmp_ _wcsicmp_ _mbsicmp_ _stricmp_l_ _wcsicmp_l_ _mbsicmp_l]等替代了。

我在编译libidn的时候，发现在命令行里面链接时会出现错误：

libidn.lib(idna.obj) : error LNK2019: unresolved external symbol \_\_imp\_\_stricmp  
referenced in function \_idna\_to\_unicode\_internal

而这句话在vs 2005 ide里面却不会出现。

但我把libidn-1.9/win32/include/config.h里面的

\#define strcasecmp stricmp  
\#define strncasecmp strnicmp

改为：

\#define strcasecmp \_stricmp  
\#define strncasecmp \_strnicmp

就都没有问题了。我就奇怪了，为什么会出现这种问题？为什么有的时候有stricmp，而有的时候没有stricmp呢？

stricmp，\_stricmp的定义在E:/Program Files/Microsoft Visual Studio 8/VC/include/string.h里面，

我们可以看到如下定义：

\#if !\_\_STDC\_\_

....................

/\* prototypes for oldnames.lib functions \*/  
\_CRT\_NONSTDC\_DEPRECATE(\_strcmpi) \_CRTIMP \_\_checkReturn int \_\_cdecl strcmpi(\_\_in\_z const char \* \_Str1, \_\_in\_z const char \* \_Str2);  
\_CRT\_NONSTDC\_DEPRECATE(\_stricmp) \_CRTIMP \_\_checkReturn int \_\_cdecl stricmp(\_\_in\_z const char \* \_Str1, \_\_in\_z const char \* \_Str2);  
\_CRT\_NONSTDC\_DEPRECATE(\_strlwr) \_CRTIMP char \* \_\_cdecl strlwr(\_\_inout\_z char \* \_Str);  
\_CRT\_NONSTDC\_DEPRECATE(\_strnicmp) \_CRTIMP \_\_checkReturn int \_\_cdecl strnicmp(\_\_in\_z const char \* \_Str1, \_\_in\_z const char \* \_Str, \_\_in size\_t \_MaxCount);  
\_CRT\_NONSTDC\_DEPRECATE(\_strnset) \_CRTIMP char \* \_\_cdecl strnset(\_\_inout\_ecount\_z(\_MaxCount) char \* \_Str, \_\_in int \_Val, \_\_in size\_t \_MaxCount);  
\_CRT\_NONSTDC\_DEPRECATE(\_strrev) \_CRTIMP char \* \_\_cdecl strrev(\_\_inout\_z char \* \_Str);  
\_CRT\_NONSTDC\_DEPRECATE(\_strset) char \* \_\_cdecl strset(\_\_inout\_z char \* \_Str, \_\_in int \_Val);  
\_CRT\_NONSTDC\_DEPRECATE(\_strupr) \_CRTIMP char \* \_\_cdecl strupr(\_\_inout\_z char \* \_Str);

\#endif /\* !\_\_STDC\_\_ \*/

从上面可以看出，如果\_\_STDC\_\_ 为0，则会有stricmp的定义，否则就没有。

[http_msdn.microsoft.com_en-us_library_ms235365_VS.80_.aspx]: http://msdn.microsoft.com/en-us/library/ms235365%28VS.80%29.aspx
[stricmp_ _wcsicmp_ _mbsicmp_ _stricmp_l_ _wcsicmp_l_ _mbsicmp_l]: http://msdn.microsoft.com/en-us/library/k59z8dwe%28VS.80%29.aspx