man file_size () - Returns the size of a file in bytes. Allegro game programming library.
NAME
file_size - Returns the size of a file in bytes. Allegro game programming library.
SYNOPSIS
#include <allegro.h>
long file_size(const char *filename);
DESCRIPTION
Returns the size of a file, in bytes. If the file does not exist or an error occurs, it will return zero and store the system error code in errno.