paquette@cs-sun-fsa.cpsc.ucalgary.ca (Trevor Paquette) (11/08/90)
Quick and I hope a fairly simple question. We have some programs
that must be able to take advantage of two co-processors on a sun.
The executables are name prog_host (no coprocessor), prog_sc (Supercard
coprocessor) and prog_qc (Quickcard coprocessor).
Each executable is in a seperate directory. I want to be able to change
my path on the fly to get at a certain executable. This is what I have
done so far.
Let's say my path is set as :
(. /usr/ucb /bin /usr/bin /usr/local/bin /home/insight/sparc/bin/itahost)
*******
itahost contains all the prog_host executables.
itaqc contains all the prog_qc executables.
itasc contains all the prog_sc executables.
I have come up with the following aliases to change which directory I will use
alias host 'echo set path=\($path\)|sed s/itaqc/itahost/|sed s/itasc/itahost/'
alias qc 'echo set path=\($path\)|sed s/itahost/itaqc/|sed s/itasc/itaqc/ '
alias sc 'echo set path=\($path\)|sed s/itaqc/itasc/ |sed s/itahost/itasc/'
These aliases of course only ECHO what the command to change the path should
be.
To actually execute the command we must put some ` around the command.
So the new aliases should be:
alias host '`echo set path=\($path\)|sed s/itaqc/itahost/|sed s/itasc/itahost/`'
alias qc '`echo set path=\($path\)|sed s/itahost/itaqc/|sed s/itasc/itaqc/ `'
alias sc '`echo set path=\($path\)|sed s/itaqc/itasc/ |sed s/itahost/itasc/`'
But these new aliases give me the following error:
`echo set path=\($path\)|sed s/itaqc/itahost/|sed s/itasc/itahost/`: Ambiguous
What am I doing wrong???????????
Trev
--
______________________________________/Through the darkness, the future past,
Trevor Paquette ICBM:51'03"N/114'05"W|The magician longs to see.
{ubc-cs,utai,alberta}!calgary!paquette|One chants out, between two worlds,
paquette@cpsc.ucalgary.ca |"Fire, walk with me."vendijb@aix.aix.kingston.ibm.com (JB Christy) (11/08/90)
In article <1990Nov8.014515.13882@cpsc.ucalgary.ca> paquette@cs-sun-fsa.cpsc.ucalgary.ca (Trevor Paquette) writes: }I have come up with the following aliases to change which directory I will use } }alias host 'echo set path=\($path\)|sed s/itaqc/itahost/|sed s/itasc/itahost/' }alias qc 'echo set path=\($path\)|sed s/itahost/itaqc/|sed s/itasc/itaqc/ ' }alias sc 'echo set path=\($path\)|sed s/itaqc/itasc/ |sed s/itahost/itasc/' } } These aliases of course only ECHO what the command to change the path should }be. }To actually execute the command we must put some ` around the command. } } So the new aliases should be: }alias host '`echo set path=\($path\)|sed s/itaqc/itahost/|sed s/itasc/itahost/`' }alias qc '`echo set path=\($path\)|sed s/itahost/itaqc/|sed s/itasc/itaqc/ `' }alias sc '`echo set path=\($path\)|sed s/itaqc/itasc/ |sed s/itahost/itasc/`' } But these new aliases give me the following error: } }`echo set path=\($path\)|sed s/itaqc/itahost/|sed s/itasc/itahost/`: Ambiguous csh parses commands before it does variable and command substitutions, so by the time it's figured out the output of your echo, it's no longer looking for a command. You have two choices. You can explicitly tell csh to parse the command after substitution (i.e. to 'eval'uate the output of your echo -- see the csh man page under the 'eval' command): alias sc 'eval `echo set path=\($path\)|sed s/itaqc/itasc/ |sed s/itahost/itasc/`' Or, more directly, you can just set the path to the proper thing yourself: alias sc 'set path=`echo \($path\)|sed s/itaqc/itasc/ |sed s/itahost/itasc/`' -- JB (Beth) Christy "She was a suicide blonde -- Resource One, Inc. dyed by her own hand." *** I speak only for myself, and half the time I get that wrong. ***
jik@athena.mit.edu (Jonathan I. Kamens) (11/09/90)
(Note the Followup-To, which probably should have been set to something in the original posting. I was all set to flame at the poster for posting a question to comp.unix.internals that doesn't have anything at all to do with Unix internals, and then I realized that he posted it to comp.unix.wizards, which is aliased to comp.unix.internals, at least at my site. :-) In article <1990Nov8.014515.13882@cpsc.ucalgary.ca>, paquette@cs-sun-fsa.cpsc.ucalgary.ca (Trevor Paquette) writes: |> alias host '`echo set path=\($path\)|sed s/itaqc/itahost/|sed s/itasc/itahost/`' |> alias qc '`echo set path=\($path\)|sed s/itahost/itaqc/|sed s/itasc/itaqc/ `' |> alias sc '`echo set path=\($path\)|sed s/itaqc/itasc/ |sed s/itahost/itasc/`' |> But these new aliases give me the following error: |> |> `echo set path=\($path\)|sed s/itaqc/itahost/|sed s/itasc/itahost/`: Ambiguous The C-shell has a problem (discussed several times in comp.unix.shell recently) with deciding exactly when the output of a backquote substitution should be expanded into multiple words. Another example of this is that typing kill `cat file-with-list-of-pids-in-it` won't work because the list of pids will all be treated as one word. This is only a problem with the "kill" shell built-in, though, so if you substitute "/bin/kill" for "kill", it works fine. The problem you are having is another manifestation of this. The way to get around it is to change your aliases. For example; alias host 'set path= (`echo $path|sed -e s/itaqc/itahost/g -e \\\ s/itasc/itahost/g`)' Note that this has the added advantages of using only one invocation of sed instead of two, and of replacing itasc and itaqc whereever they appear in your path, not just the first time. You could also solve the problem by using eval instead of backquotes, although you might have to make some minor changes to your aliases in that case too. Figuring out how to do this is left as an exercise to the reader :-). -- Jonathan Kamens USnail: MIT Project Athena 11 Ashford Terrace jik@Athena.MIT.EDU Allston, MA 02134 Office: 617-253-8085 Home: 617-782-0710
jpe@egr.duke.edu (John P. Eisenmenger) (11/09/90)
From article <1990Nov8.014515.13882@cpsc.ucalgary.ca>, by paquette@cs-sun-fsa.cpsc.ucalgary.ca (Trevor Paquette): > So the new aliases should be: > alias host '`echo set path=\($path\)|sed s/itaqc/itahost/|sed s/itasc/itahost/`' > alias qc '`echo set path=\($path\)|sed s/itahost/itaqc/|sed s/itasc/itaqc/ `' > alias sc '`echo set path=\($path\)|sed s/itaqc/itasc/ |sed s/itahost/itasc/`' > But these new aliases give me the following error: > > `echo set path=\($path\)|sed s/itaqc/itahost/|sed s/itasc/itahost/`: Ambiguous > > What am I doing wrong??????????? try these: alias host 'set path = ( `echo $path | sed -e s/itaqc/itahost/ -e s/itasc/itahost/` ) alias qc 'set path = ( `echo $path | sed -e s/itahost/itaqc/ -e s/itasc/itaqc/` ) alias sc 'set path = ( `echo $path | sed -e s/itahost/itasc/ -e s/itaqc/itasc/` ) -John
tif@doorstop.austin.ibm.com (Paul Chamberlain) (11/10/90)
In article <1990Nov8.014515.13882@cpsc.ucalgary.ca> paquette@cs-sun-fsa.cpsc.ucalgary.ca (Trevor Paquette) writes: >I have come up with the following aliases to change which directory I will use >... >alias host '`echo set path=\($path\)|sed s/itaqc/itahost/|sed s/itasc/itahost/`' >... Untested but much more likely to succeed alias follows: alias host 'set path=(`echo $path|sed s/itaqc/itahost/|sed s/itasc/itahost/`)' ... But, if I were you, I'd do something like this (which I even tested): alias host 'set path=(`echo $path|sed "s/ita[a-z]*/itahost/"`)' Paul Chamberlain | I do NOT represent IBM. tif@doorstop, sc30661 at ausvm6 512/838-7008 | ...!cs.utexas.edu!ibmchs!auschs!doorstop.austin.ibm.com!tif