_strnicmp, _wcsnicmp, _mbsnicmp, _strnicmp_l, _wcsnicmp_l, _mbsnicmp_l

مقالة
06/30/2010

Compare characters of two strings without regard to case.

int _strnicmp(
   const char *string1,
   const char *string2,
   size_t count 
);
int _wcsnicmp(
   const wchar_t *string1,
   const wchar_t *string2,
   size_t count 
);
int _mbsnicmp(
   const unsigned char *string1,
   const unsigned char *string2,
   size_t count 
);
int _strnicmp_l(
   const char *string1,
   const char *string2,
   size_t count,
   _locale_t locale
);
int _wcsnicmp_l(
   const wchar_t *string1,
   const wchar_t *string2,
   size_t count,
   _locale_t locale
);
int _mbsnicmp_l(
   const unsigned char *string1,
   const unsigned char *string2,
   size_t count,
   _locale_t locale
);

Parámetros

string1, string2
Null-terminated strings to compare.
count
Number of characters to compare.
locale
Locale to use.

Valor devuelto

Indicates the relationship between the substrings as follows.

Return value	Description
< 0	string1 substring less than string2 substring
0	string1 substring identical to string2 substring
> 0	string1 substring greater than string2 substring

On an error, _mbsnicmp returns _NLSCMPERROR, which is defined in STRING.H and MBSTRING.H.

Comentarios

The _strnicmp function lexicographically compares, at most, the first count characters of string1 and string2*.* The comparison is performed without regard to case; _strnicmp is a case-insensitive version of strncmp. The comparison ends if a terminating null character is reached in either string before count characters are compared. If the strings are equal when a terminating null character is reached in either string before count characters are compared, the shorter string is lesser.

The characters from 91 to 96 in the ASCII table ('[', '\', ']', '^', '_', and '`') will evaluate as less than any alphabetic character. This ordering is identical to that of stricmp.

_wcsnicmp and _mbsnicmp are wide-character and multibyte-character versions of _strnicmp. The arguments and return value of _wcsnicmp are wide-character strings; those of _mbsnicmp are multibyte-character strings. _mbsnicmp recognizes multibyte-character sequences according to the current multibyte code page and returns _NLSCMPERROR on an error. For more information, see Code Pages. These three functions behave identically otherwise. These functions are affected by the locale setting. The versions without the _l suffix use the current locale for their locale-dependent behavior. The versions with the _l suffix are identical except that they use the locale passed in instead. For more information, see Locale.

All of these functions validate their parameters. If either string1 or string2 is a null pointer, the invalid parameter handler is invoked, as described in Parameter Validation. If execution is allowed to continue, these functions return _NLSCMPERROR and set errno to EINVAL.

Generic-Text Routine Mappings