In the course of maintaining your system, you are likely to receive files in various versions of the PostScript format. Following are some of the main differences between the Encapsulated PostScript File (EPSF) version 3.0 format and PostScript file format:
EPSF is used to describe the appearance of a single page, while the PostScript format is used to describe the appearance of one or more pages.
EPSF requires the following two DSC (document structuring conventions) Header comments:
%!PS-Adobe-3.0 EPSF-3.0 %%BoundingBox: llx lly urx ury |
If a PS 3.0 file conforms to the document structuring conventions, it should start with the comment:
%!PS-Adobe-3.0 |
A PS file does not have to contain any DSC comment statements if it does not conform to the DS conventions.
Some PostScript language operators, such as copypage, erasepage, or exitserver must not be used in an EPS file.
Certain rules must be followed when some other PostScript operators, such as nulldevice, setscreen, or undefinefont are used in an EPS file.
All PostScript operators can be used in a PS file.
An EPS file can be (and usually is) inserted into a PS file, but a PS file must not be inserted into an EPS file if that will violate the rules for creating valid EPS files.
An EPS file may contain a device-specific screen preview for the image it describes. A PS file usually contains screen previews only when EPS files are included in that PS file.
The recommended filename extension for EPS files is .EPS or .eps, while the recommended filename extension for PS files is .PS or .ps.
The EPSF format was designed for importing the PostScript description of a single page or part of a page, such as a figure, into a document, without affecting the rest of the description of that document. EPS code should be encapsulated, that is, it should not interfere with the PS code that may surround it, and it should not depend on that code.
The EPSF format is usually used for the output from a program that was designed for the preparation of illustrations or figures, (such as Illustrator) and as input into desktop publishing programs (such as Adobe Systems FrameMaker). Most desktop publishing programs can produce the description of a document in the PostScript format that may include the imported EPS code.
For more information about these formats, see the book PostScript Language Reference Manual, Second Edition, Addison-Wesley Publishing Company, Inc., Reading, MA, 1990. You can get several documents on the EPS and PS formats from the Adobe Systems PostScript file server by entering the following at a UNIX prompt, and then following the instructions you get from the file server:
mail ps-file-server@adobe.com Subject: help Ctrl+D |
You can get a description of the EPSF format in the PS format by sending the following message to that file server:
send Documents EPSF2.0.ps |