How to recognize microsoft office file types?

[Innocent]

Hey Everyone,

I am supposed to write a software tools in C language for debian
linux which recognizes different microsoft office file types i.e. .doc, .xls,
..ppt etc.

How can these file types be recognized? Recognition by extension is useless
because the extension can be changed so any other way?

Thanks.

 

[DL]

If the extension is changed from an office component extension to something
else, then they cannot be opened with any Office component; perhaps theres
more to your question than simply that

 

[Beth Melton]

All the file extensions do is associate a file with an application so when
it's opened outside of the application, such as by double-clicking it from
the Windows Explorer or the Desktop, Windows 'knows' which application to
start. If you change the file extension you can still open the file in the
Office application but you need to use the Open dialog box from within the
application.

~Beth Melton
Microsoft Office MVP

 

[DL]

I omitted to mention that

All the file extensions do is associate a file with an application so when
it's opened outside of the application, such as by double-clicking it from
the Windows Explorer or the Desktop, Windows 'knows' which application to
start. If you change the file extension you can still open the file in the
Office application but you need to use the Open dialog box from within the
application.

~Beth Melton
Microsoft Office MVP

 

[Beth Melton]

I *thought* you'd know something like that! ;-)

I omitted to mention that

 

[Steve Rindsberg]

Hey Everyone,

I am supposed to write a software tools in C language for debian
linux which recognizes different microsoft office file types i.e. .doc, .xls,
..ppt etc.

How can these file types be recognized? Recognition by extension is useless
because the extension can be changed so any other way?

Have a look here:
http://www.microsoft.com/interop/docs/OfficeBinaryFormats.mspx

This info documents the file formats used in Office 97-2003

The formats change entirely in 2007.