1 #include <u.h> 2 #include <libc.h> 3 4 int strncmp(char * s1,char * s2,long n)5strncmp(char *s1, char *s2, long n) 6 { 7 unsigned c1, c2; 8 9 while(n > 0) { 10 c1 = *s1++; 11 c2 = *s2++; 12 n--; 13 if(c1 != c2) { 14 if(c1 > c2) 15 return 1; 16 return -1; 17 } 18 if(c1 == 0) 19 break; 20 } 21 return 0; 22 } 23