File-name mapping

This page applies to Harlequin v13.1r0 and later; both Harlequin Core and Harlequin MultiRIP.

If files were only ever accessed from the PostScript language, it would be sufficient just to describe the PostScript-language naming conventions for files. However, many files referred to from the PostScript language are stored as files on disk accessible through the underlying operating system.

This does not have to be the case, however. Some specialized PostScript implementations access files only through the PostScript language and have their own custom file system implementation; others have no disks at all and use the names to reference areas of memory.

Though [RB2] says that filenames and details of filing operations are platform-specific (and indeed they are in Adobe’s interpreters), this is inadequate in the RIP environment because the implementation is cross-platform, and because application and utility software (especially font downloaders) make detailed assumptions about a RIP’s file system, largely based on the Apple LaserWriter. Because the Harlequin RIP on a PC or UNIX system can be accessed using EtherTalk from a Macintosh, it must look just like the same program on the Macintosh, or indeed embedded in a laser printer, especially in the file names it uses, even though those may not match the requirements of the underlying operating system.

The PostScript-language does not place any special syntactic requirements on file names (they can even start with a percent sign when an explicit device name is given so that there is no confusion, though we do not recommend this). However, the NUL character almost always causes unavoidable problems because most operating system calls use this character to terminate their string parameters. See the full explanation of file and device name limits in File names, device names, and relative devices.

Names of files managed by the operating system do have special syntactic requirements: by restricting length, the characters allowed in a file name, and whether or not names are case-sensitive. This means that a mapping must be established between PostScript-language file names and operating system specific file names.