amr@dukee.egr.duke.edu (Anthony M. Richardson) (05/28/90)
I'll probably feel pretty silly for not being able to figure this out myself, but I've already gone well beyond my frustration level... How does one use eval if you want to read one of the parameters from an input file (or environment variable)? The 1.3 manual (the little white book) I have says you can do this and even gives an example that goes something like (from memory) eval < t:qwe value2=1 op=- to env:loop This is supposed to decrement the value in qwe and store the new value in loop and allows you to do loops. I've tried this and can't get it (or any seemingly logical permutations to work). Can anyone help? Thanks in advance, Tony p.s. I already know that several PD and commercial shells can do this quite easily, but I really want to know how to do it with eval and the standard commodore shell.
jsivier@ux1.cso.uiuc.edu (Jonathon Sivier ) (06/03/90)
In article <918@cameron.egr.duke.edu> amr@dukee.egr.duke.edu (Anthony M. Richardson) writes: >How does one use eval if you want to read one of the parameters from >an input file (or environment variable)? The 1.3 manual (the little >white book) I have says you can do this and even gives an example >that goes something like (from memory) > > eval < t:qwe value2=1 op=- to env:loop I think one thing you have to do if you are going to use input redirection with '<' is to redifine the braket characters to something like '{}'. Otherwise the parser see's the '<' as the beginning of an input parameter. I hope this helps some. -- Jonathan Sivier jsivier@ux1.cso.uiuc.edu
peterk@cbmger.UUCP (Peter Kittel GERMANY) (06/08/90)
In article <918@cameron.egr.duke.edu> amr@dukee.egr.duke.edu (Anthony M. Richardson) writes: >How does one use eval if you want to read one of the parameters from >an input file (or environment variable)? The 1.3 manual (the little >white book) I have says you can do this and even gives an example >that goes something like (from memory) > > eval < t:qwe value2=1 op=- to env:loop > ^^^ Well, in the print shops with their proportional fonts it becomes often VERY difficult to tell where a space should go and where not. This statement deals with redirection of input, so there MUST NOT BE A SPACE in "<t:qwe" !!! BTW, in my version this whole part of the script looks a bit different: type env:loop eval <env:loop >NIL: to=t:qwe{$$} value2=1 op=- ? copy t:qwe{$$} env:loop ; don't abuse type where copy is meant -- Best regards, Dr. Peter Kittel E-Mail to Commodore Frankfurt, Germany rutgers!cbmvax!cbmbsw!cbmger!peterk