defcon_chan/main.c

/*
defcon-chan: a simple C program that fetches current/last known DEFCON level into your terminal!

requirements: libcurl

compiling w/ GCC: gcc main.c -o defcon -lcurl

running: ./defcon

author: hornetmaidan
*/

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <curl/curl.h>

#define URL "https://defconwarningsystem.com/code.dat"
#define FILENAME ".defcon.txt" // saves the last known DEFCON level into a local file(hidden for aesthetic purposes)

// ANSI colors
#define COLOR_RESET "\033[0m"
#define COLOR_RED "\033[31m"
#define COLOR_GREEN "\033[32m"
#define COLOR_YELLOW "\033[33m"
#define COLOR_BLUE "\033[34m"
#define COLOR_MAGENTA "\033[35m"
#define COLOR_CYAN "\033[36m"
#define COLOR_WHITE "\033[37m"
#define COLOR_BLINK "\033[5m"

// write callback function for curl handler

size_t write_data(void *ptr1, size_t size, size_t nmemb, FILE *stream) {
    size_t written = fwrite(ptr1, size, nmemb, stream);
    return written;
}

int main(void) {

    CURL *curl;
    CURLcode result;
    FILE *fp;

    char last_known[256] = "N/A";
    char failsafe[256] = "N/A";

    curl = curl_easy_init();

    // load cached DEFCON level into the buffer, also check for file access
    if (access(FILENAME, F_OK) != -1) {
        fp = fopen(FILENAME, "rb");
        if (fp != NULL) {
            if (fgets(last_known, sizeof(last_known), fp) != NULL) {
                // remove newline char
                size_t len = strlen(last_known);
                if (len > 0 && last_known[len - 1] == '\n') {
                    last_known[len - 1] = '\0';
                }
                strncpy(failsafe, last_known, sizeof(failsafe));
                failsafe[sizeof(failsafe) - 1] = '\0';  // ensure null termination
            } else {
                fprintf(stderr, "%serror reading from file :(%s\n", COLOR_MAGENTA, COLOR_RESET);
            }

            fclose(fp);
        } else {
            fprintf(stderr, "%sfailed to open file :9%s\n", COLOR_MAGENTA, COLOR_RESET);
        }
    } else {
        fprintf(stderr, "%sno cache file found, creating...%s\n", COLOR_MAGENTA, COLOR_RESET);
    }


    fp = fopen(FILENAME, "w");
    // a lil bit of error handling here and there
    
    if (curl == NULL) {
        fprintf(stderr, "%sHTTP request failed :(%s\n", COLOR_MAGENTA, COLOR_RESET);
        curl_easy_cleanup(curl);
    }
    // fun begins
    fprintf(stdout, "%s----------------------------------------------------------------------\n", COLOR_GREEN);
    fprintf(stdout, "defcon-chan is at your service! getting the current DEFCON level desu~\n");
    // setting options for curl
    curl_easy_setopt(curl, CURLOPT_URL, URL);
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);
    curl_easy_setopt(curl, CURLOPT_WRITEDATA, fp);
    result = curl_easy_perform(curl); // actual request performing
    curl_easy_cleanup(curl);

    if (result != CURLE_OK) {
        fprintf(stderr, "%serror: %s%s\n", COLOR_MAGENTA, curl_easy_strerror(result), COLOR_RESET);
        fprintf(stdout, "%sservice is currently unreachable, the last DEFCON level is: %s%s\n", COLOR_CYAN, failsafe, COLOR_RESET);
        fp = fopen(FILENAME, "w");
        fprintf(fp, "%s", failsafe);
        fclose(fp);
        return -1;
        
    } else {
        fflush(fp);
        fclose(fp);
        fp = fopen(FILENAME, "r"); // i don't know if there's a better way to do this but since there are only 5 conditions - why not?
        if (fgets(last_known, sizeof(last_known), fp) != NULL) {
        if (strcmp(last_known, "5") == 0)
        {
            fprintf(stdout, "the current DEFCON level is: %s%s%s - FADE OUT%s%s\n", COLOR_BLUE, COLOR_BLINK, last_known, COLOR_RESET, COLOR_RESET);
        }
        else if (strcmp(last_known, "4") == 0)
        {
            fprintf(stdout, "the current DEFCON level is: %s%s%s - DOUBLE TAKE%s%s\n", COLOR_GREEN, COLOR_BLINK, last_known, COLOR_RESET, COLOR_RESET);
        }
        else if (strcmp(last_known, "3") == 0)
        {
            fprintf(stdout, "the current DEFCON level is: %s%s%s - ROUND HOUSE%s%s\n", COLOR_YELLOW, COLOR_BLINK, last_known, COLOR_RESET, COLOR_RESET);
        }
        else if (strcmp(last_known, "2") == 0)
        {
            fprintf(stdout, "the current DEFCON level is: %s%s%s - FAST PACE%s%s\n", COLOR_RED, COLOR_BLINK, last_known, COLOR_RESET, COLOR_RESET);
        }
        else if (strcmp(last_known, "1") == 0)
        {
            fprintf(stdout, "the current DEFCON level is: %s%s%s - COCKED PISTOL%s%s\n", COLOR_WHITE, COLOR_BLINK, last_known, COLOR_RESET, COLOR_RESET);
            fprintf(stdout, "%%ssWHAT ARE YOU DOING? RUN FOR YOUR LIFE!%s%s\n", COLOR_MAGENTA, COLOR_BLINK, COLOR_RESET, COLOR_RESET);
        }
        else
        {
            fprintf(stderr, "%serror reading the DEFCON level from the file%s\n", COLOR_RED, COLOR_RESET);
        }
    }
    fclose(fp);
    fp = fopen(FILENAME, "w");
    if (strcmp(last_known, "N/A") == 0) {
    fprintf(fp, "%s", failsafe); // writing the last safe DEFCON value ever known
    fprintf(stdout, "failsafe engaged with level of %s", failsafe);
    }
    else {
        fprintf(fp, "%s", last_known);
    }
    }
    fclose(fp);
    fprintf(stdout, "%s----------------------------------------------------------------------%s\n", COLOR_GREEN, COLOR_RESET);

    return 0;
}