-/* Wrappers to calling from function called "f" of fopen(), fclose() and fgets()
- * and calling exit_err() with appropriate error messages.
+/* Wrappers to calling from function called "f" of fopen(), fclose(), fgets()
+ * and fwrite() and calling exit_err() with appropriate error messages.
+ */
+extern FILE * try_fopen(char * path, char * mode, char * f);
+extern void try_fclose(FILE * file, char * f);
+extern void try_fwrite(void * ptr, size_t size, size_t nmemb, FILE * stream,
+ char * f);
+
+
+
+/* Wrapper to calling fgets() from function called "f". The return code of
+ * fgets() is returned unless it is NULL *and* ferror() indicates that an error
+ * occured; otherwise end of file is assumed and NULL is returned properly.