File management system and file management method capable of managing unoccupied blocks without the use of dummy data

A file management method, comprising dividing the storage area on the storage device into data blocks in a specific unit size, having the data block numbers and the file offset addresses paired and registered on a block table, said file offset addresses written on the said data blocks, and managing unoccupied blocks by the unoccupied block management means so that a data block allocation means takes the writing step by referring to said block table when directed to write, characterized in that:

• when there is a request to write, the starting point of writing a new data being at an offset address one or more blocks apart from the last offset address of a specific file, said unoccupied block management means manages as number of unoccupied blocks the number obtained by subtracting the number of said dummy blocks without real data from the number of unoccupied data blocks.

A storage medium which has a file managing procedure stored therein comprising dividing the memory space on the storage device into data blocks in a specific unit size, having the data block numbers and the file offset addresses paired and registered on a block table, said file offset addresses written on the said data blocks, and managing unoccupied blocks so as to take the writing step by referring to said block table when directed to write, characterized in that there is stored a procedure of managing as number of unoccupied blocks the number obtained by subtracting the number of said dummy blocks without real data from the number of unoccupied data blocks at said unoccupied block management means when there is a request to write, the starting point of writing a new data being at an offset address one or more blocks apart from the last offset address of a specific file.