I worked on fixing some very strange issues with strings. Similar to the TTF_OpenFont command, using miniApplication.location changed it, which resulted in using the wrong directory path.

This is very strange behaviour. To fix it, I created a new const char* variable and assigned the location of the miniApplication to it. This solved the problem, but I am not sure why the string gets changed. The solution is not very pretty and I need to do some adjustments. the location of the Resource structure should be const.

const char *miniAppModuleLocation = miniApplication.location;
printf("%s\n", miniAppModuleLocation);
char *testCommand = "test -f ";
char *fileLocation = "app/output/calculations.csv";
char *createCommand = calloc(strlen(testCommand) + strlen(miniAppModuleLocation) + strlen(fileLocation), 
                             sizeof(char));
strcpy(createCommand, testCommand);
strcat(createCommand, miniAppModuleLocation);
strcat(createCommand, fileLocation);
printf("%s\n", createCommand);
int getCalcFile = system(createCommand);
printf("%s\n", createCommand);
free(createCommand);

if (getCalcFile == 0)
{
    char *cdCommand = "cd ";
    char *removeCommand = " && rm calculations.csv";
    createCommand = calloc( strlen(miniApplication.location) + strlen(cdCommand) + strlen(removeCommand), 
                               sizeof(char));
    getCalcFile = system(createCommand);
    free(createCommand);

    if (getCalcFile != 0)
    {
        printf("Calculations CSV removal failed\n, %d", errno);
        exit(EXIT_FAILURE);
    }
}

Also, I updated the GetResults function to read the output CSV file. It is still very buggy but it's getting there.

struct Results GetResults(char *location, char *value)
{
    struct Results results;
    char *commandPartFirst = "cd ";
    char *commandPartSecond = " && fpm run -- ";
    char *command = calloc(    strlen(location) + strlen(value) + strlen(commandPartFirst) + strlen(commandPartSecond), 
                                                    sizeof(char));

    char *contentsCSV = "/app/output/calculations.csv";
    char *csvLocation = calloc(strlen(location) + strlen(contentsCSV), sizeof(char));
    strcpy(csvLocation, location);
    strcat(csvLocation, contentsCSV);
    printf("%s\n", csvLocation);

    strcpy(command, commandPartFirst);
    strcat(command, location);
    strcat(command, commandPartSecond);
    strcat(command, value);

    int getSystemInfo = system(command);

    if (getSystemInfo != 0)
    {
        printf("Something went wrong!\n");
        results.maxHeight = 0;
        results.timeToMaximumHeight = 0;
        results.timeToLand = 0;
        return results;
    }

    FILE *file = fopen(csvLocation, "r");
    char line[1024];
    int counter = 0;

    while(fgets(line, 1024, file))
    {
        if (counter == 0)
        {
            counter++;
            continue;
        }
        char *temp = strdup(line);
        char *stopFirstString;
        char *stopSecondString;
        char *stopThirdString;
        printf("Get Result 1: %s\n", GetField(temp, 0));
        printf("Get Result 2: %s\n", GetField(temp, 1));
        printf("Get Result 3: %s\n", GetField(temp, 2));
        results.maxHeight = strtod(GetField(temp, 0), &stopFirstString);
        results.timeToMaximumHeight = strtod(GetField(temp, 1), &stopSecondString);
        results.timeToLand = strtod(GetField(temp, 2), &stopThirdString);

        free(temp);
    }

    printf("%s\n", command);
    free(command);
    free(csvLocation);
    fclose(file);
    return results;
}