Function strncmp

freebsd/libkern/strncmp.c:37–51

#include <sys/libkern.h>

int
strncmp(const char *s1, const char *s2, size_t n)
{

	if (n == 0)
		return (0);
	do {
		if (*s1 != *s2++)
			return (*(const unsigned char *)s1 -
				*(const unsigned char *)(s2 - 1));
		if (*s1++ == '\0')
			break;
	} while (--n != 0);
	return (0);
}