clock_gettime problem

Good morning. I wrote the following code:

Code:

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#include <stdio.h>
#include <stdlib.h>
#include <time.h>

struct timespec ts;

int main()
{
  int value;
  srand(clock_gettime(CLOCK_REALTIME, &ts));
  value = rand();   
  printf("\nThe value: %d\n", value);   
  return 0;   
}

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I try to get a random int but I always get the same value when I compile the program with gcc -g rand.c -o rand -lrt

The value: 1804289383

What am I doing wrong?

I already tried with CLOCK_MONOTONIC too.

clock_gettime() returns an int value of 0 to indicate success (and an int value of -1 to indicate failure). It is that 0 value that you are using to initialize the PRNG.

I suggest you redo your program to use (parts of) the structure ts.

You didn't read the manual for starters.

clock_gettime(3): clock/time functions - Linux man page

Quote:

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Return Value

clock_gettime(), clock_settime() and clock_getres() return 0 for success, or -1 for failure (in which case errno is set appropriately).

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You're getting the same answer each time, because it returns success/fail each time.

This isn't the same as time()

I got it. Many thanks

Code:

---

#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int main()
{
  int value;
  srand(time(NULL));
  value = rand();   
  printf("\nThe value: %d\n", value);   
  return 0;   
}

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