On Thu, 2021-11-25 at 02:40 +0900, DaeHyun Sung wrote: > Hmm, I have hwp v3.0 file and hwp v5.0 file. > > I also attached test hwp v5.0 file "hello.hwp" and hwp v3.0 file > "hellov3.hwp". Yeah, hello.hwp... $ gsf list hello.hwp hello.hwp: d 2021-08-14 22:45:54 0 *root* f 1519 DocInfo f 30 PrvText d 2021-08-14 22:45:54 0 Scripts f 16 Scripts/DefaultJScript f 13 Scripts/JScriptVersion d 2021-08-14 22:45:54 0 BodyText f 215 BodyText/Section0 f 5817 PrvImage d 2021-08-14 22:45:54 0 DocOptions f 524 DocOptions/_LinkDoc f 256 FileHeader f 477 HwpSummaryInformation is a "Microsoft Compound File Binary Format" aka "Compound Document File Format" or "ole" file format. https://en.wikipedia.org/wiki/Compound_File_Binary_Format we have lots of existing support for this so I expect the earlier mentioned snippet will help.