#include <9pm/u.h> #include <9pm/libc.h> char* strncat(char *s1, char *s2, long n) { char *os1; os1 = s1; while(*s1++) ; s1--; while(*s1++ = *s2++) if(--n < 0) { s1[-1] = 0; break; } return os1; }