Frequently Asked Questions

I have received a number of questions from readers, and many of them are the same. Since these seem to be popular questions, I thought I would list them here, along with my usual answers. Of course, you will also find the FAQ for the comp.lang.postscript Usenet group to be useful. There are far more FAQs in that list than are here. By the way, if anyone knows of a better answer to any of these question, let me know.

Is there a utility to convert a PostScript file into my favorite word processors format?

Short answer: no.

Long answer: Maybe. There is a utility to convert PostScript files into ASCII files (it tries to extract the text), but it can not work on every PostScript file. The problem here is that PostScript is a full programming language, and there are many ways to accomplish a given thing. It would be next to impossible for a program to look at some piece of PostScript and decide what the contents are. It would be possible to write a program which would accept some subset of PostScript files and convert them to some useful format, but it would be difficult to write (and it could not handle all possible PostScript files).

I have a Hawat-Pickford 520xz ink jet printer without PostScript, is there anyway I can print PostScript files on it?

Yep. There are a number of PostScript interpreters which run on your computer and can print out PostScript files. There are versions of these kinds of utilities for the Mac and for DOS/Windows machines. I have never used one of these utilities, so I can not recommend any particular one. Go to your friendly neighborhood dealer or your favorite catalog to see what they have. There is a section in the PostScript FAQ on this issue. You may also want to have a look at GhostScript. GhostScript can print PostScript files on certain printers.

Can you point me to a good previewer for my computer?

My first recommendation is GhostScript. Hey, it's free; and it does a good job. It is also able to convert PostScript files to a number of other graphics formats, so it can be handy there. There are also a number of commercial previewers. I have not used any of these commercial packages, so I can not recommend any of them in particular.

Can you tell me X about Acrobat and PDF files?

Nope. I don't know anything about Acrobat or PDF files. Check out the Adobe website. You may find the information you need there.

How do I print out a PostScript file from my computer?

The procedures and tools vary, depending upon the machine. I'm going to assume that you have a PostScript enabled printer and either received or wrote the PostScript file (if you have the application that generated the file, you should just use your application's print command or menu).

Assuming your PostScript printer is on port LPT1: (it really doesn't matter), all you need to do is:
where FILE.PS is whatever your file is.
Mac OS X
Mac OS X comes with a built-in utility to convert PostScript files to PDF. Just opening the PostScript file from the Finder is sufficient to start the conversion. If you want to print the file and you do not have a PostScript printer, you can just print the PDF file you got normally. If you do have a PostScript printer, you will probably have to follow the instructions for Unix below.
UNIX and its cousins
Depending upon your system, just printing the file as if it were a text file should send it to the printer correctly. Most UNIX systems are clever enough to recognize the PostScript file from the %! comment at the beginning of the file. For example, on a BSD system:
should do the trick.

My company has an Acme Laz-o-Tron typesetter. We're having problems printing out a set of color separations for a TIFF photograph processed by FotoWerks Pro+. Why are the separations coming out wrong?

Beats me.

I'm afraid the basic fact of the matter is that I'm not very bright. Nope. Nope. Nope. I'm not very bright. I also don't know a heck of a lot (you know, there's a joke: a dog, sitting in front of a computer says to his doggy friend, “You know, on the Internet, no one knows you're a dog...” for “a dog” substitute “not an expert,” and you've got something). I do know a fair amount about PostScript. Despite my deep and abiding love for fine typography, however, and despite the fact that ink runs in my blood, I don't know much about the printing industry or of the equipment they use.

If you have questions about your software or your printer, I recommend contacting the manufacturer or a posting a question to a newsgroup (if there is a relevant one). I just do not know the particulars on different printers or software (unless it's something I own or use).

I'm looking at two printers, one has PostScript while the other does not. Which should I buy?

This is a common and very good question (there is a related one on whether or not to buy a PostScript extension for an existing printer). The answer, as it usually does, boils down to a definite, “It depends.”

If your main printing task consists of printing the monthly report or letters to clients, friends, family members, or whomever, then you will probably find PostScript to be an extravagance. This is especially true if you have no interest in mucking about with fonts or graphics. In other words, for light-duty, mainly text, print once and send to whomever kind of work, the answer is, “No.”

If you are a desktop publisher, you are writing a book and want to send the book to your publisher electronically, or you do a lot of graphics work and want the graphics to look good regardless of the printer, the answer is yes. In all of these cases, you have a complex printing task and may want to proof your document at home or in the office but then send it out for final (higher quality) printing. Generally speaking, the same PostScript file will look the same regardless of which PostScript printer you use, with one exception: if one printer is capable of better print quality (finer lines, smoother curves, gentler shades of grey) than the other, your document should benefit from these increased capabilities without the PostScript file's needing to be changed. You are benefiting from PostScript's device independence.

As for graphics intensive work, I find the EPS format to be the best for line drawing type graphics (i.e. no bitmap images) that I will want to include in a document. I very often want to print an image generated by one package when the word processor may be from a different vendor. Many times (incredible to tell) I sometimes need to include a graphic made on one computer system in a document on a completely different system! In such a heterogeneous environment, EPS graphics are just about the only reasonable option. Also, many top-quality drafting/painting programs generate their best output in EPS (on some windowing systems, the built-in graphic format can have a limited resolution that results in badly displaced elements in a printed image). If you use EPS graphics, you must have a PostScript enabled printer if you want to print them out with any quality at all.

As with most things in our complex universe, it all depends upon what you are going to do. You must sit down and evaluate your needs and probable work habits. If you think you will benefit from PostScript's unique characteristics enough to justify the cost, then go for it.

Is it possible to concatenate two PostScript files together into a single file?

Yes and no. If you do not care about being DSC compliant, then all you have to do is to slap the two files together into one. If that does not work, you could wrap each in a save/restore pair:

  % contents of the first file
  % contents of the second file

The problem with this approach is that it is not compliant with the DSC, so you can not do anything with the concatenated file. Previewers and print spoolers will have problems recognizing pages and would not be able to shuffle them appropriately. Other post-processing engines would fail to work with them too (for instance, you would not be able to display the file in two up format.

If the two PostScript files are DSC compliant, came from the same tool, and use the same resources (the acid test is if they have the same preamble... the definitions at the start of the file before you get to the first page), then you could concatenate the files by starting with the common preamble, followed by the pages of the first file, followed by the pages of the second file. You would have to recognize the pages by looking at the page comments much like we did in the post-processing examples.

You can not play this trick with files from different tools (or with different preambles). The problem is that a page in a file depends upon the definitions in the preamble, if you miss a definition, or if two files have different definitions for the same name, you really can not concatenate the files and keep the result compliant with the DSC.

There are various scripts available out there to do the concatenation under these restrictions. Look around for tools like “psmerge,” “psconcat,” and the like, and see what might work for you (psmerge is part of the psutils package and is available on many Unix work-alikes, and comes bundled with Mac OS X).

Is it possible to create a PDF from a PostScript file?

Yes. GhostScript comes with a utility called ps2pdf which will do the job. Also, Mac OS X has the ability built-in: just double-click on the PostScript file in the Finder, and it will convert the file to PDF for you and give you an option to save the results. I’m sure there are other tools to do the job, too.

Is it true that you are one of the most stunningly attractive men on the net?

Why, yes. How did you know?

Okay, so maybe no one has ever asked me that. It was worth a shot. Maybe you wouldn't have noticed.

By the way, you finished reading the FAQ, so here's a mailto link for you to send me e-mail if you don't see your question here.