#include <unistd.h>
#define ERROR_EXIT(fmt, ...) do { \
- fprintf(stderr, fmt, ## __VA_ARGS__); \
- return EXIT_FAILURE; \
- } while (0)
+ fprintf(stderr, fmt, ## __VA_ARGS__); \
+ return EXIT_FAILURE; \
+ } while (0)
static int usage(char *name)
{
- fprintf(stderr, "Usage: %s <nb>\n", name);
- fprintf(stderr, " => return <nb> bytes from getrandom()\n");
- return EXIT_FAILURE;
+ fprintf(stderr, "Usage: %s <nb>\n", name);
+ fprintf(stderr, " => return <nb> bytes from getrandom()\n");
+ return EXIT_FAILURE;
}
int main(int argc, char *argv[])
{
- if (argc != 2)
- return usage(argv[0]);
+ if (argc != 2)
+ return usage(argv[0]);
- if (isatty(STDOUT_FILENO))
- ERROR_EXIT("Not outputting random to a tty\n");
+ if (isatty(STDOUT_FILENO))
+ ERROR_EXIT("Not outputting random to a tty\n");
- int nbtot = atoi(argv[1]);
- if (nbtot < 1)
- ERROR_EXIT("Invalid <nb> param (must be > 0)\n");
+ int nbtot = atoi(argv[1]);
+ if (nbtot < 1)
+ ERROR_EXIT("Invalid <nb> param (must be > 0)\n");
- char buf[256];
- int len = sizeof(buf);
- while (nbtot > 0) {
- if (nbtot <= sizeof(buf))
- len = nbtot;
- if (syscall(SYS_getrandom, buf, len, 0) == -1)
- ERROR_EXIT("getrandom() failed: %s\n", strerror(errno));
- if (write(STDOUT_FILENO, buf, len) != len)
- ERROR_EXIT("write() failed: %s\n", strerror(errno));
- nbtot -= sizeof(buf);
- }
+ char buf[256];
+ int len = sizeof(buf);
+ while (nbtot > 0) {
+ if (nbtot <= sizeof(buf))
+ len = nbtot;
+ if (syscall(SYS_getrandom, buf, len, 0) == -1)
+ ERROR_EXIT("getrandom() failed: %s\n", strerror(errno));
+ if (write(STDOUT_FILENO, buf, len) != len)
+ ERROR_EXIT("write() failed: %s\n", strerror(errno));
+ nbtot -= sizeof(buf);
+ }
+
+ return 0;
}