Implementing filemanager

Implementing and testing filemanager and upgrading epanet_output library to use it.

src/util/filemanager.h

@@ -8,6 +8,14 @@
 
 #include <stdio.h>
 
+
+// F_OFF Must be a 8 byte / 64 bit integer for large file support
+#ifdef _WIN32 // Windows (32-bit and 64-bit)
+#define F_OFF __int64
+#else         // Other platforms
+#define F_OFF off_t
+#endif
+
 #define FILE_MAXNAME 259
 #define FILE_MAXMODE 3
 
@@ -17,21 +25,22 @@ extern "C" {
 #endif
 
 
-typedef struct file_s {
-    char filename[FILE_MAXNAME + 1],
-    FILE *file;
-    char mode[FILE_MAXMODE + 1];
-} file_handle_t;
+typedef struct file_s file_handle_t;
 
 
-file_handle_t *create_file_manager(const char *filename, const char *file_mode);
+file_handle_t *create_file_manager();
 
-int delete_file_manager(file_handle_t *file_handle);
+void delete_file_manager(file_handle_t *file_handle);
 
 
-int open_file(file_handle_t *file_handle);
+int open_file(file_handle_t *file_handle, const char *filename, const char *file_mode);
+
+int seek_file(file_handle_t *file_handle, F_OFF offset, int whence);
+
+F_OFF tell_file(file_handle_t *file_handle);
+
+size_t read_file(void *ptr, size_t size, size_t nmemb, file_handle_t *file_handle);
 
-FILE *get_file(file_handle_t *file_handle);
 
 int close_file(file_handle_t *file_handle);