char *read_file(const char *filename)
{
    int i=0;
    FILE *readFile = fopen(filename, "r");

    if(!readFile) return NULL;
    if(feof(readFile)) return NULL;

    char *returnString=malloc(sizeof(char));
    returnString[i]=fgetc(readFile);

    while(!feof(readFile)){ //Lukee merkin kerrallaan kunnes tullaan tiedoston loppuun
        i++;
        returnString = realloc(returnString, (i+1)*sizeof(char));
        returnString[i] = fgetc(readFile);
    }

    i++;
    returnString = realloc(returnString, (i+1)*sizeof(char));
    returnString[i] = NULL;
    fclose(readFile);
    return returnString;
}