How to use Adobe PostScript language files properly
| About 90% of the Adobe PostScript problems at CDF are the result of violating one rule:
Illustrations should be EPS files and should be generated and tested as such!
Many of the problems where Ghostscript, gs, will display the document, but the document will not print on a printer is that the document was created using Microsoft or AppleSoft document preparation software. This is the result of these software assuming that the documention is being prepared to print on a specific printer type and that it is the responsibility of the document preparation software to condition the printer appropriately. Unfortunately, these assumptions are all too often incorrect in large computing environments with a variety of printer types and with print spooling systems which actually have the responsibility to condition the printer on which the document actually is printed. If the actual printer does not understand the embedded conditioning commands, which may be Hewlett-Packard Printer Control Language (HPCL), Adobe PostScript printer type specific commands, or some other printer language, then the usual result is a failure to print. The presence of the printer conditioning code may also confuse the print spooling system as to what type of print file it is with the result the file prints in an inappropriate manner; e.g., Adobe PostScript code is printed as ASCII text instead of being executed to generate page images.
In the case where Ghostscript, gs, will display the file, but it will not display properly when using a Ghostscript managing program such as Ghostview (ghostview) or gv, is that the file has improper Document Structuring Comments (DSC; see below). The wrapper programs are dependent on there either being no DSC or that the DSC is proper. The case of no DSC results in not having a page number that works.
Another major source of problems is improper copying of Adobe Postscript files between machines with very different operating systems. Most Adobe PostScript files are ASCII and should be moved as text. Adobe PDF files are binary and must be moved as such. For example, FTP and Kermit must be told which method to use.
Magic bullets for addressing Adobe PostScript problems in the general case are mathematically impossible.
Unreliable tricks and techniques for modifying Adobe PostScript files do exist that sometimes work. Such tricks and techniques are not presented in this document because they are not general or reliable.