deamon-demo.c

// Deamon Demo

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>

int main(int argc, char* argv[])
{
        FILE *fp = NULL;
        pid_t process_id = 0;
        pid_t sid = 0;
        int count = 0;

        // Create child process
        process_id = fork();
        if (process_id < 0)
        {
                printf("fork failed!\n");
                exit(1);
        }

        if (process_id > 0)
        {
                printf("process_id of child process %d\n", process_id);
                exit(0);
        }

        // unmask the file mode
        umask(0);
        sid = setsid();
        if (sid < 0)
        {
                exit(1);
        }

        chdir("C:\\Boush");

        // Close stdin, stdout and stderr
        close(STDIN_FILENO);
        close(STDOUT_FILENO);
        close(STDERR_FILENO);
        fp = fopen("Log.txt", "w+");
        while (1)
        {
                count++;
                sleep(1);
                fprintf(fp, "=== Logging info...\n");
                fflush(fp);
                if (25 == count)
                {
                        printf("=== deamon process stop...\n");
                        exit(0);
                }
        }
        fclose(fp);
        return 0;
}