If no source file is given, or if sourcefile is `-', psorder reads from the standard input file.

-d

Re-order the pages of the document in downward or descending order. This is typically used to change the order of a document to be printed by a printer that stacks pages face-up, such as an Apple LaserWriter or LaserWriter Plus.

-u

Specifies forward order, and is the default. It is used to try and ensure the correct ordering when a document will be printed by a printer that stacks the pages face-down.

-f

Force psorder to re-order the pages, even if the document claims that its page order is not to be trifled with. This option should only be used experimentally, as it may cause documents to print incorrectly.