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#include <stdio.h> #include <unistd.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <stdlib.h> #define BUF_SIZE 256 int main(void) { int fd = open("/dev/urandom", O_RDONLY); int i; char buf[BUF_SIZE]; if (fd < 0) return 1; for (i = 0; i < 4; ++i) read(fd, buf, BUF_SIZE); close(fd); return 0; }