Format
#include <string.h>
int memcmp(const void *buf1, const void *buf2, size_t count);Language Level: ANSI
Threadsafe: Yes.
Description
The memcmp() function compares the first count bytes of buf1 and buf2.
Return Value
The memcmp() function returns a value indicating the relationship between the two buffers as follows:
| Value | Meaning |
| Less than 0 | buf1 less than buf2 |
| 0 | buf1 identical to buf2 |
| Greater than 0 | buf1 greater than buf2 |
Example that uses memcmp()
This example compares first and second arguments passed to main() to determine which, if either, is greater.
#include <stdio.h>
#include <string.h>
int main(int argc, char ** argv)
{
int len;
int result;
if ( argc != 3 )
{
printf( "Usage: %s string1 string2\n", argv[0] );
}
else
{
/* Determine the length to be used for comparison */
if (strlen( argv[1] ) < strlen( argv[2] ))
len = strlen( argv[1] );
else
len = strlen( argv[2] );
result = memcmp( argv[1], argv[2], len );
printf( "When the first %i characters are compared,\n", len );
if ( result == 0 )
printf( "\"%s\" is identical to \"%s\"\n", argv[1], argv[2] );
else if ( result < 0 )
printf( "\"%s\" is less than \"%s\"\n", argv[1], argv[2] );
else
printf( "\"%s\" is greater than \"%s\"\n", argv[1], argv[2] );
}
}
/**************** If the program is passed the arguments **************
***************** firststring and secondstring, ************
***************** output should be: ************
When the first 11 characters are compared,
"firststring" is less than "secondstring"
**********************************************************************/Related Information