#include #include // memcpy, memcmp, memset #include // strlen using namespace std; char* strcpy(char* to, const char* from) { return memcpy(to, from, strlen(from)+1) ? to : to; } int strcmp(const char* str1, const char* str2) { return memcmp(str1, str2, strlen(str1)); } char* strcat(char* to, const char* from) { return memcpy(&to[strlen(to)], from, strlen(from)+1) ? to : to; } int main() { const char NL = '\n'; // prevent excessive flushing char src[10] = "abcdefghi"; char dst[30]; char concat[] = "jklmnopqrstuvwxyz"; char lowerString[] = "compare 1"; char higherString[] = "compare 2"; char equalString[] = "compare 1"; int result; cout << "Copy \"\" -> empty dst: " << strcpy(dst, "") << NL; cout << "Copy src -> empty dst: " << strcpy(dst, src) << NL; cout << "Copy \"\" -> filled dst: " << strcpy(dst, "") << NL; cout << NL << "Compares..." << NL; result = strcmp(lowerString, higherString); cout << " " << (result == 0 ? "Match" : (result < 0 ? "first string lower" : "second string lower")) << NL; result = strcmp(lowerString, equalString); cout << " " << (result == 0 ? "Match" : (result < 0 ? "first string lower" : "second string lower")) << NL; result = strcmp(higherString, lowerString); cout << " " << (result == 0 ? "Match" : (result < 0 ? "first string lower" : "second string lower")) << NL; cout << NL << ">> prefill dst (strcpy)" << NL; strcpy(dst, src); cout << "Concat filled dst + \"\": "<< strcat(dst, "") << NL; cout << "Concat filled dst + concat: "<< strcat(dst, concat) << NL; cout << NL << ">> wipe dst (memset)" << NL; memset(dst, 0, 30); // wipe cout << "Concat empty dst + empty dst: "<< strcat(dst, dst) << NL; cout << "Concat empty dst + concat: "<< strcat(dst, concat) << NL; // flush once; faster == more output cout << endl; return 0; }

strfuncs 1-liner challenge [strcpy, strcmp, strcat -> memcpy, memcmp, ternary]