1 #include <u.h> 2 #include <libc.h> 3 4 ulong 5 truerand(void) 6 { 7 ulong x; 8 static int randfd = -1; 9 10 if(randfd < 0) 11 randfd = open("/dev/random", OREAD|OCEXEC); 12 if(randfd < 0) 13 sysfatal("can't open /dev/random"); 14 if(read(randfd, &x, sizeof(x)) != sizeof(x)) 15 sysfatal("can't read /dev/random"); 16 return x; 17 } 18