strncmp, wcsncmp, _mbsncmp
Compare characters of two strings.
intstrncmp(constchar*string1,constchar*string2,size_tcount**);**
intwcsncmp(constwchar_t*string1,constwchar_t*string2,size_tcount**);**
int_mbsncmp(constunsignedchar*string1,constunsignedcharstring2**,size_tcount);**
| Routine | Required Header | Compatibility |
| strncmp | <string.h> | ANSI, Win 95, Win NT |
| wcsncmp | <string.h> or <wchar.h> | ANSI, Win 95, Win NT |
| _mbsncmp | <mbstring.h> | Win 95, Win NT |
For additional compatibility information, see Compatibility in the Introduction.
Libraries
| LIBC.LIB | Single thread static library, retail version |
| LIBCMT.LIB | Multithread static library, retail version |
| MSVCRT.LIB | Import library for MSVCRT.DLL, retail version |
Return Value
The return value indicates the relation of the substrings of string1 and string2 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, _mbsncmp returns _NLSCMPERROR, which is defined in STRING.H and MBSTRING.H.
Parameters
string1, string2
Strings to compare
count
Number of characters to compare
Remarks
The strncmp function lexicographically compares, at most, the first count characters in string1 and string2 and returns a value indicating the relationship between the substrings. strncmp is a case-sensitive version of _strnicmp. Unlike strcoll, strncmp is not affected by locale. For more information on the LC_COLLATE category, see setlocale.
wcsncmp and _mbsncmp are wide-character and multibyte-character versions of strncmp. The arguments and return value of wcsncmp are wide-character strings; those of _mbsncmp are multibyte-character strings. _mbsncmp 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. wcsncmp and _mbsncmp are case-sensitive versions of _wcsnicmp and _mbsnicmp.
Generic-Text Routine Mappings
| TCHAR.H Routine | _UNICODE & _MBCS Not Defined | _MBCS Defined | _UNICODE Defined |
| _tcsnccmp | strncmp | _mbsnbcmp | wcsncmp |
| _tcsncmp | strncmp | _mbsnbcmp | wcsncmp |
Example
/* STRNCMP.C */
#include <string.h>
#include <stdio.h>
char string1[] = "The quick brown dog jumps over the lazy fox";
char string2[] = "The QUICK brown fox jumps over the lazy dog";
void main( void )
{
char tmp[20];
int result;
printf( "Compare strings:\n\t\t%s\n\t\t%s\n\n", string1, string2 );
printf( "Function:\tstrncmp (first 10 characters only)\n" );
result = strncmp( string1, string2 , 10 );
if( result > 0 )
strcpy( tmp, "greater than" );
else if( result < 0 )
strcpy( tmp, "less than" );
else
strcpy( tmp, "equal to" );
printf( "Result:\t\tString 1 is %s string 2\n\n", tmp );
printf( "Function:\tstrnicmp _strnicmp (first 10 characters only)\n" );
result = _strnicmp( string1, string2, 10 );
if( result > 0 )
strcpy( tmp, "greater than" );
else if( result < 0 )
strcpy( tmp, "less than" );
else
strcpy( tmp, "equal to" );
printf( "Result:\t\tString 1 is %s string 2\n\n", tmp );
}
Output
Compare strings:
The quick brown dog jumps over the lazy fox
The QUICK brown fox jumps over the lazy dog
Function: strncmp (first 10 characters only)
Result: String 1 is greater than string 2
Function: _strnicmp (first 10 characters only)
Result: String 1 is equal to string 2
See Also _mbsnbcmp, _mbsnbicmp, strcmp, strcoll Functions, _strnicmp, strrchr, _strset, strspn