ref: 7feab4dc5913c8d072d57e9cc7cc7b3815037fe8
dir: /sys/src/libc/port/readn.c/
#include <u.h> #include <libc.h> long readn(int f, void *av, long n) { char *a; long m, t; a = av; t = 0; while(t < n){ m = read(f, a+t, n-t); if(m <= 0){ if(t == 0) return m; break; } t += m; } return t; }