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memcmp

Compare characters in two buffers.

intmemcmp(constvoid*buf1,constvoid*buf2,size_tcount**);**

Routine Required Header Compatibility
memcmp <memory.h> or <string.h> ANSI, 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 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

Parameters

buf1

First buffer

buf2

Second buffer

count

Number of characters

Remarks

The memcmp function compares the first count bytes of buf1 and buf2 and returns a value indicating their relationship.

Example

/* 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>

void main( void )
{
   char first[]  = "12345678901234567890";
   char second[] = "12345678901234567891";
   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 if( result > 0 )
      printf( "First is greater than second.\n" );
   printf( "Compare '%.20s' to '%.20s':\n", first, second );
   result = memcmp( first, second, 20 );
   if( result < 0 )
      printf( "First is less than second.\n" );
   else if( result == 0 )
      printf( "First is equal to second.\n" );
   else if( result > 0 )
      printf( "First is greater than second.\n" );
}

Output

Compare '1234567890123456789' to '1234567890123456789':
First is equal to second.
Compare '12345678901234567890' to '12345678901234567891':
First is less than second.

Buffer Manipulation Routines

See Also   _memccpy, memchr, memcpy, memset, strcmp, strncmp