Article View: comp.lang.postscript
Article #1273Re: Novice Question
From: rsilverman
Date: Sat, 28 Oct 1989 14:39
Date: Sat, 28 Oct 1989 14:39
23 lines
874 bytes
874 bytes
In article <7834@cg-atla.UUCP>, kincaid@cg-atla.UUCP (Tom Kincaid ) writes:
> Is there a way to:
>
> -Check to see if V1 is defined
>
> -if it is defined, do nothing.
>
> -if it is not defined, then define it.
>
>
> Thanks,
> Tom
Tom,
The "known" operator tries to look up its operand in the context of the
dictionary stack, and returns true or false accordingly. Thus:
/V1 known not { /V1 null def } if
will do what you want (replace "null" with whatever you want).
Richard Silverman
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Path: arc1-ca.pugleaf.net!utzoo!attcan!uunet!samsung!brutus.cs.uiuc.edu!psuvax1!rutgers!cmcl2!yale!eagle!rsilverman From: rsilverman@eagle.wesleyan.edu Newsgroups: comp.lang.postscript Subject: Re: Novice Question Message-ID: <2884@eagle.wesleyan.edu> Date: 28 Oct 89 14:39:31 GMT References: <7834@cg-atla.UUCP> Distribution: comp Lines: 23