1 #include <plan9.h> 2 3 long readn(int f,void * av,long n)4 readn(int f, void *av, long n) 5 { 6 char *a; 7 long m, t; 8 9 a = av; 10 t = 0; 11 while(t < n){ 12 m = read(f, a+t, n-t); 13 if(m <= 0){ 14 if(t == 0) 15 return m; 16 break; 17 } 18 t += m; 19 } 20 return t; 21 } 22