ftype
Displays or modifies file types that are used in file name extension associations. Windows commands reference
On Windows
Windows
Displays or modifies file types that are used in file name extension associations. If used without an assignment operator (=), this command displays the current open command string for the specified file type. If used without parameters, this command displays the file types that have open command strings defined. NOTE: This command is only supported within cmd.exe and is not available from PowerShell. Though you can use cmd /c ftype as a workaround.
ftype [<filetype>[=[<opencommandstring>]]]ftypeftype txtfileftype example=assoc .pl=PerlScriptftype PerlScript=perl.exe %1 %*set PATHEXT=.pl;%PATHEXT%<filetype>Specifies the file type to display or change.<opencommandstring>Specifies the open command string to use when opening files of the specified file type./?Displays help at the command prompt.%0 or %1Gets substituted with the file name being launched through the association.%*Gets all of the parameters.%2, %3, ...Gets the first parameter (%2), the second parameter (%3), and so on.%~<n>Gets all of the remaining parameters starting with the *n*th parameter, where n can be any number from 2 to 9.