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#include <u.h>
#include <libc.h>
ulong
truerand(void)
{
int i, n;
uchar buf[sizeof(ulong)];
static int randfd = -1;
if(randfd < 0){
randfd = open("/dev/random", OREAD);
if(randfd < 0)
randfd = open("/dev/srandom", OREAD); /* OpenBSD */
if(randfd < 0)
sysfatal("can't open /dev/random: %r");
fcntl(randfd, F_SETFD, FD_CLOEXEC);
}
for(i=0; i<sizeof(buf); i += n)
if((n = readn(randfd, buf+i, sizeof(buf)-i)) < 0)
sysfatal("can't read /dev/random: %r");
return *((ulong*)buf);
}
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