Keil Logo

Technical Support

On-Line Manuals

C251 User's Guide

C251 Introduction Compiling Programs Language Extensions Preprocessor Advanced Programming Error Messages Library Reference Library Files Source Code Standard Types jmp_buf va_list Macros CBYTE CVAR CARRAY DARRAY DBYTE DVAR HARRAY HBYTE HVAR NARRAY NBYTE NVAR XARRAY XBYTE XVAR Routines by Category Buffer Manipulation Routines Character Routines Data Conversion Routines Intrinsic Routines Math Routines Memory Allocation Routines Stream I/O Routines String Routines Variable Length Argument Routines Miscellaneous Routines Include Files SFR Definitions absacc.h assert.h ctype.h float.h intrins.h limits.h math.h setjmp.h stdarg.h stddef.h stdio.h stdlib.h string.h Reference _chkdouble_ _chkfloat_ _crol_ _cror_ _getkey _irol_ _iror_ _lrol_ _lror_ _nop_ _testbit_ _tolower _toupper abs acos asin assert atan atan2 atof atoi atol cabs calloc ceil cos cosh exp fabs fcalloc ffree finit_mempool floor fmalloc fmemcpy fmemset frealloc free getchar gets hmemccpy hmemchr hmemcmp hmemcpy hmemmove hmemset hstrcmp hstrcpy hstrlen hstrncpy init_mempool isalnum isalpha iscntrl isdigit isgraph islower isprint ispunct isspace isupper isxdigit labs log log10 longjmp malloc memccpy memchr memcmp memcpy memmove memset modf offsetof pow printf putchar puts rand realloc scanf setjmp sin sinh sprintf sqrt srand sscanf strcat strchr strcmp strcpy strcspn strlen strncat strncmp strncpy strpbrk strpos strrchr strrpbrk strrpos strspn tan tanh toascii toint tolower toupper ungetchar va_arg va_end va_start vprintf vsprintf xcalloc xfree xinit_mempool xmalloc xmemcpy xmemset xrealloc Appendix

memcmp

Summary
#include <string.h>

int memcmp (
  void *buf1,          /* first buffer */
  void *buf2,          /* second buffer */
  unsigned int len);   /* bytes to compare */
Description

The memcmp function compares the first len bytes from buf1 and buf2 and returns a value indicating their relationship as follows:

Value Description
< 0 buf1 less than buf2
= 0 buf1 equal to buf2
> 0 buf1 greater than buf2
Return Value

The memcmp function returns a positive, negative, or zero value indicating the relationship of buf1 and buf2.

See Also

memccpy, memchr, memcpy, memmove, memset

Example
#include <string.h>
#include <stdio.h> /* for printf */

void tst_memcmp (void) {
  char hexchars [] = "0123456789ABCDEF";
  char hexchars2 [] = "0123456789abcdef";
  char i;

  i = memcmp (hexchars, hexchars2, 16);

  if (i < 0)
    printf ("hexchars < hexchars2\n");
  else if (i > 0)
    printf ("hexchars > hexchars2\n");
  else
    printf ("hexchars == hexchars2\n");
}
  Arm logo
Important information

This site uses cookies to store information on your computer. By continuing to use our site, you consent to our cookies.

Change Settings

Privacy Policy Update

Arm’s Privacy Policy has been updated. By continuing to use our site, you consent to Arm’s Privacy Policy. Please review our Privacy Policy to learn more about our collection, use and transfers
of your data.