| 摘要 |
PURPOSE:To compress a file by an easy method, and also, to easily incorporate it into an application, and to shorten the compression time by reading out each record from a file having plural pieces of records consisting of plural items, and comparing each record with a record of one case before. CONSTITUTION:In a memory area 12, a first record is stored, and in an input area 11, a second record is stored. A comparing part 13 compares the contents of the memory area 12 with the contents of the input area 11 at every item. In an output area 14, the contents of the item which coincides in the comparing part 13 with regard to the second record are replaced with a coincident mark and stored. In such a manner, each record is read out of a file having plural pieces of records consisting of plural items, and compared with the record of one record before at every item. As for the item whose contents are the same, it is replaced with a character for showing a fact that no change is present thereon. |
