NT Syntax


Display or change the link between a fileType and an executable program

   FTYPE [fileType]=[executable_path]
FTYPE FTYPE [fileType] FTYPE [fileType]= key fileType : The type of file executable_path : The executable program including any command line parameters

More than one file extension may be associated with the same File Type.
e.g. both the extension .JPG and the extension .JPEG may be associated with the File Type "jpegfile"

File Types can be displayed in the Windows Explorer GUI: [View, Options, File Types] however the spelling is usually different to that expected by the FTYPE command e.g. the File Type "txtfile" is displayed in the GUI as "Text Document"and "jpegfile" is displayed as "image/jpeg"

Several FileTypes can be linked to the same executable application, but
one FileType cannot be linked to more than one executable application.

FTYPE file type will display the current executable program for that file type.

FTYPE without any parameters will display all FileTypes and the executable program for each.

Defining command line parameters

It is almost always necessary to supply command line parameters so that when a document is opened not only is the relevant application loaded into memory but the document itself also loaded into the application. To make this happen the filename of the document must be passed back to the application.

Command line parameters are exactly like batch file parameters, %0 is the executable program and %1 will reference the document filename

so a simple command line might be:

MyApplication.exe "%1"

If any further parameters are required by the application they can be passed as %2, %3. To pass ALL parameters to an application use %*. To pass all the remaining parameters starting with the nth parameter, use %~n where n is between 2 and 9.

The FileType should always be created before making a File Association

For example:

FTYPE htmlfile="C:\PROGRA~1\Plus!\MICROS~1\iexplore.exe" -nohome
ASSOC .html=htmlfile

FTYPE pagemill.html=C:\PROGRA~1\Adobe\PAGEMI~1.0\PageMill.exe "%1"
ASSOC .html=pagemill.html

FTYPE rtffile="C:\Program Files\Windows NT\Accessories\WORDPAD.EXE" "%1"
ASSOC .rtf=rtffile

FTYPE word.rtf.8="C:\Program Files\Microsoft Office\Office\winword.exe" /n
ASSOC .rtf=word.rtf.8

Switching a File Association between multiple applications

If you have multiple applications that use the same file extension, the ASSOC command can be used to switch the file extension between the different FileTypes.

Deleting a FileType

Specify executable_path=nothing and the FTYPE command will delete the executable_path for that FileType.
For example:
FTYPE htmlfile=

Backing up your FileTypes

FTYPE >backup_types.txt
ASSOC >backup_ext.txt

Restoring your FileTypes from a Backup

FOR /F "tokens=* delims=" %G IN (backup_types.txt) DO FTYPE %G
FOR /F "tokens=* delims=" %G IN (backup_ext.txt) DO ASSOC %G

Note that unlike simply backing up the registry, this method will actually recreate all the CLASS id's
If you put the commands above in a batch file change the %G to be %%G

Using File associations at the command line

If you have a file association between .DOC and Word for Windows then at a command prompt you can open a document with any of the following commands:

Start "My Document.doc"
"Monthly Report.doc"

note that the file extension must be supplied for this to work

Related Commands:

ASSOC - Change file extension associations
Batch file to list the application associated with a file extension
ASSOCIAT - One step file association (Resource Kit)

Equivalent Linux BASH commands:


Simon Sheppard