1 /* strncmp -- compare two strings, stop after n bytes. 2 This function is in the public domain. */ 3 4 /* 5 6 @deftypefn Supplemental int strncmp (const char *@var{s1}, @ 7 const char *@var{s2}, size_t @var{n}) 8 9 Compares the first @var{n} bytes of two strings, returning a value as 10 @code{strcmp}. 11 12 @end deftypefn 13 14 */ 15 16 #include <ansidecl.h> 17 #include <stddef.h> 18 19 int 20 strncmp(const char *s1, const char *s2, register size_t n) 21 { 22 register unsigned char u1, u2; 23 24 while (n-- > 0) 25 { 26 u1 = (unsigned char) *s1++; 27 u2 = (unsigned char) *s2++; 28 if (u1 != u2) 29 return u1 - u2; 30 if (u1 == '\0') 31 return 0; 32 } 33 return 0; 34 } 35
