Luna/apps/app.c

#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <time.h>
#include <unistd.h>

void bye()
{
    printf("byeee!\n");
}

int main()
{
    atexit(bye);
    printf("Welcome to %s from userspace (pid %d)!\n", "Luna", getpid());

    FILE* f = fopen("/etc/motd", "r");
    if (!f)
    {
        perror("fopen");
        return 1;
    }

    char buffer[512];
    size_t nread = fread(buffer, 1, sizeof(buffer), f);
    buffer[nread] = 0;

    printf("/etc/motd says: %s", buffer);

    fclose(f);

    time_t now = time(NULL);
    printf("date: %s", ctime(&now));
}