1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21
/* * strcmp.c */ #include <string.h> int strcmp(const char *s1, const char *s2) { const unsigned char *c1 = (const unsigned char *)s1; const unsigned char *c2 = (const unsigned char *)s2; unsigned char ch; int d = 0; while (1) { d = (int)(ch = *c1++) - (int)*c2++; if (d || !ch) break; } return d; }