Skip to main content
B
bluesky231
Participant
February 6, 2014
Question

what is the proper Ctrl-D behavior?

  • February 6, 2014
  • 1 reply
  • 2534 views

Postscript language reference 3rd edition states that Ctrl-D is not part of the postscript language but a communication control character.

Adobe Technote #5009 states that Ctrl-C, Ctrl-T, or Ctrl-D are not part of the language specification but a communication protocol. They should be handled by lower I/O layer and should not appear in the job file.

In reality, Ctrl-D do appear in the job file and printers (interpreters) can handle it properly. So what is the official Adobe spec in regarding to this "proper" behavior?

Anyone can point to where to find this info?

Thanks a lot

This topic has been closed for replies.

1 reply

Dov Isaacs
Dov Isaacs
Legend
February 6, 2014

Binary control characters such as Ctrl-D should not appear within a PostScript job unless it is a binary job and is using a communications protocol that depends on structures such as special packets to separate jobs. Otherwise, you are at the mercy of the lower level communications protocols that scan for such characters prior to passing them to the PostScript interpreter. In the case of Ctrl-D, typically such a lower level non-binary communication protocol would treat Ctrl-D as end of job.

          - Dov

- Dov Isaacs, former Adobe Principal Scientist (April 30, 1990 - May 30, 2021)
T
Test Screen Name
Legend
February 7, 2014

Since it is often impossible to separate communication protocol from language, the PPD can be used to determine correct behaviour for a driver.

Dov Isaacs
Dov Isaacs
Legend
February 7, 2014

Test Screen Name wrote:

Since it is often impossible to separate communication protocol from language, the PPD can be used to determine correct behaviour for a driver.

The operative words here are can be used since there is no requirement that the PPD provide communication protocol information and most PostScript printers support multiple communications protocols. That having been said, if the PPD indicates that either BCP or TBCP protocols are available, if you use a BCP or TBCP protocol channel, then Ctrl-D will definitely be interpreted as end of job. The first character following the Ctrl-D character will be treated as the first character of the next job!

          - Dov

- Dov Isaacs, former Adobe Principal Scientist (April 30, 1990 - May 30, 2021)
Terms & ConditionsAccessibility statement
Using the community Terms of use Privacy Cookie preferences Do not sell or share my personal information ad choicesAdChoices