Very Computer

Hi!

I'd like this code:

        P="Hello world"
        Q=P
        echo ??

to generate the output "Hello world" where ?? only conatins the
variable Q (i.e NO P:s in the echo argument), how do I do this in ksh?

I've tried ${${Q}} and a whole lot of other things, but I can't
get it working.
Is it possible to solv?

Thanks!

/Thomas

Sorry, I should have been a little more thourough in my description.
The thing is I want a shell script to use the value of an environment
varibel to acees another environment variable.

Maybe it would've been more obvious if I gave the example:
        P_TEXT="Hello world"
        Q=P
        echo ??

I've tried things like ${${Q}_TEXT}
Any suggestions to this?

/Thomas

Quote:> Hi!

> I'd like this code:

>    P="Hello world"
>    Q=P
>    echo ??

> to generate the output "Hello world" where ?? only conatins the
> variable Q (i.e NO P:s in the echo argument), how do I do this in ksh?

> I've tried ${${Q}} and a whole lot of other things, but I can't
> get it working.
> Is it possible to solv?

> Thanks!

> /Thomas

   P="Hello world"
   Q=$P                   # and NOT Q=P

   print $Q               # or echo $Q but I prefer print

Is that what you want?

Greetings

Markus

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Thank you Markus!
If somebody else want to know, here it is!
(got it from Markus in a mail)

#!/bin/ksh
P_TEXT="Hello world" Q=P
eval R='$'${Q}_TEXT
print $R

p="Hello world"
q=p
eval echo $"$q"

Adam.

Try:
        P="Hello world"
        Q=$P                    <--- Note this line changes
        echo $Q                 <--- then simple echo :)

or...
        P="Hello world"
        Q=P                     <--- This line is as given in question
        eval echo $`echo $Q`    <--- Use eval to evaluate

But why use the last one? The first solution I've given is much simpler...

Chris...

Quote:>Hi!

>I'd like this code:

>    P="Hello world"
>    Q=P
>    echo ??

>to generate the output "Hello world" where ?? only conatins the
>variable Q (i.e NO P:s in the echo argument), how do I do this in ksh?

>I've tried ${${Q}} and a whole lot of other things, but I can't
>get it working.
>Is it possible to solv?

>Thanks!

>/Thomas

eval echo \$$Q

I've not tested this in ksh but AFAIK it works in just aboput all
sh-like shells.

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  Thomas> Hi!  I'd like this code:

  Thomas>    P="Hello world"
  Thomas>    Q=P
  Thomas>    echo ??

  Thomas> to generate the output "Hello world" where ?? only conatins
  Thomas> the variable Q (i.e NO P:s in the echo argument), how do I
  Thomas> do this in ksh?

  Thomas> I've tried ${${Q}} and a whole lot of other things, but I
  Thomas> can't get it working.  Is it possible to solv?

$ P="hello world"
$ Q=P
$ eval echo \$$Q
hello world      

: Hi!
: I'd like this code:
:       P="Hello world"
:       Q=P
:       echo ??
: to generate the output "Hello world" where ?? only conatins the
: variable Q (i.e NO P:s in the echo argument), how do I do this in ksh?
: I've tried ${${Q}} and a whole lot of other things, but I can't
: get it working.
: Is it possible to solv?

You are thinking about:

$ eval echo \$$Q
Hello world

but ksh93 (free for the download) has "reference variables" thus:

$ typeset -n Q=P
$ print $Q
Hello world

-Kevin Koehler