How to see the daemon process's output in Linux?

Question

I wrote a test.c:

#include <unistd.h>
#include <stdio.h>

int main()
{
    while(1)
    {
        sleep(1);
        printf("====test====\r\n");
    }
    return 0;
}

then i compile it : gcc ./test.c -o ./test and the i wrote a shell script:

#!/bin/sh
./test & 

and then i made this script to be executed automatically on system boot. then I login to the Linux system using secureCRT in SSH protocol. using "ps aux | grep test" i can see the test process running, but i just cannot see the test's output, some people told me because the test output to tty, and i am using pts. could anybody tell me the specific reason and how can i get the output? thanks in advance!

Answer 1

It doesn't output anything because it got no terminal attached.

If you want your output to be visible to every terminal connected to the system, use wall

./test | wall

(it will be very annoying)

I suggest you to redirect the output to a log file.