utility.h

#ifndef H_UTILITY
#define H_UTILITY

namespace util{

    /**
     * Returns a string (char*) allocated dynamically, use free() to free memory
     * @return char pointer to text contents read from file. NULL if there were
     * errors.
     * @param fileName Path to file. 
    */
    char *read_file(const char *fileName);
    /**
     * Counts number of bytes bytes in file and returs that number.
     * @return Size of file in bytes.
     * @param stream Pointer to a FILE object that identifies the stream.
    */
    const size_t get_file_size(FILE *stream);
    /**
     * Opens a file and checks errors. perror is printed in case of error opening file.
     * @return FILE pointer in case of success, nullptr otherwise.
     * @param file_path path to file.
     * @param mode fopen mode. 
    */
    FILE *safe_fopen(const char* file_path, const char* mode);
    /**
     * Checks for errors before closing file.
     * @return A non-zero value is returned in the case that the error indicator associated with the stream is set.
     * Otherwise, zero is returned.
     * @param stream Pointer to a FILE object that identifies the stream.
    */
    const int safe_fclose(FILE *stream);

    /**
     * Copies data to a binary file, then can be readed using read_data() function.
     * @return A non-zero value is returned in the case that the error indicator associated with the stream is set.
     * Otherwise, zero is returned.
     * @param file_path Path to file.
     * @param data Ponter to the data to be copied.
     * @param size Size (int bytes) of the data chunk.
    */
    template<typename T>
    int save_data(const char *file_path, T &data, size_t size){
    FILE *f = safe_fopen(file_path, "wb+");
    
    fwrite(data, size, 1, f);

    return safe_fclose(f);
    }
    /**
     * Reads data from a binary file generated by save_data() function, and stores it a new array of the specified type.
     * Use read_data<float>(file_path) to get a pointer to an array of floats;
     * @return Pointer to an array of contents
     * @param file_path Path to file.
    */
    template<typename T>
    T* read_data(const char *file_path){
        FILE *f = safe_fopen(file_path, "rb");
        size_t size = get_file_size(f);
        
        T* res = (T*)malloc(size);
        fread(res, size, 1, f);

        safe_fclose(f); 
        return res;
    }
        
}

#endif