#include int strcmp(const char *s1, const char *s2) { while(*s1 && (*s1 == *s2)) { s1++; s2++; } return *(const unsigned char*)s1 - *(const unsigned char*)s2; } int strncmp( const char * s1, const char * s2, int n ) { while ( n && *s1 && ( *s1 == *s2 ) ) { ++s1; ++s2; --n; } if ( n == 0 ) { return 0; } else { return ( *(unsigned char *)s1 - *(unsigned char *)s2 ); } }