memcmp, wmemcmp
Compare characters in two buffers.
int memcmp(
const void *buf1,
const void *buf2,
size_t count
);
int wmemcmp(
const wchar_t * buf1,
const wchar_t * buf2,
size_t count
);
Parameters
buf1
First buffer.buf2
Second buffer.count
Number of characters (bytes for memcmp, wide characters for wmemcmp).
Return Value
The return value indicates the relationship between the buffers.
Return value |
Relationship of first count bytes of buf1 and buf2 |
|---|---|
< 0 |
buf1 less than buf2 |
0 |
buf1 identical to buf2 |
> 0 |
buf1 greater than buf2 |
Remarks
Compares the first count characters of buf1 and buf2 and returns a value indicating their relationship.
Requirements
Routine |
Required header |
|---|---|
memcmp |
<memory.h> or <string.h> |
wmemcmp |
<wchar.h> |
For additional compatibility information, see Compatibility in the Introduction.
Libraries
All versions of the C run-time libraries.
Example
// crt_memcmp.c
/* This program uses memcmp to compare
* the strings named first and second. If the first
* 19 bytes of the strings are equal, the program
* considers the strings to be equal.
*/
#include <string.h>
#include <stdio.h>
int main( void )
{
char first[] = "12345678901234567890";
char second[] = "12345678901234567891";
int int_arr1[] = {1,2,3,4};
int int_arr2[] = {1,2,3,4};
int result;
printf( "Compare '%.19s' to '%.19s':\n", first, second );
result = memcmp( first, second, 19 );
if( result < 0 )
printf( "First is less than second.\n" );
else if( result == 0 )
printf( "First is equal to second.\n" );
else
printf( "First is greater than second.\n" );
printf( "Compare '%d,%d' to '%d,%d':\n", int_arr1[0], int_arr1[1], int_arr2[0], int_arr2[1]);
result = memcmp( int_arr1, int_arr2, sizeof(int) * 2 );
if( result < 0 )
printf( "int_arr1 is less than int_arr2.\n" );
else if( result == 0 )
printf( "int_arr1 is equal to int_arr2.\n" );
else
printf( "int_arr1 is greater than int_arr2.\n" );
}
Output
Compare '1234567890123456789' to '1234567890123456789':
First is equal to second.
Compare '1,2' to '1,2':
int_arr1 is equal to int_arr2.
.NET Framework Equivalent
Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.