AIX

Hi All,

Does anyone familiar with “Rexx interpret” know of a script equivalent?

For those that don't know “Rexx interpret”, here's how a script might look.

variable='echo Hello World!'
interpret $variable

Output is Hello World! because $variable was interpreted.

Thanks,

Lou

Are you looking to learn shell scripting based on your knowledge of REXX? Or is this just a one liner you need translated?

variable='echo Hello World!'
interpret $variable
------------------------
The equivalent in ksh:
variable='Hello World!'
echo $variable

or

echo "Hello World"

If memory serves, there is a REXX interpreter for AIX, I don't know if it's a base package or a pay feature though.

Hi Kawdes,

Thanks for checking out my post.

Your example is not quite what I want.

My variable contains the echo command itself, yours contains only "Hello World".

Yes, I'm learning scripting and I could use an interpret equivalent if there is one. Not trying to shoe-horn scripting into Rexx if that's what your question means.

Thanks,

Lou

Oh, I see what you are wanting... I think...

REXX:
variable='echo Hello World!'
interpret $variable
--------------------------
In the ksh:
variable='echo Hello World!'
eval $variable

This will execute the contents of $variable instead of just displaying it.

Exactly what I was looking for Kawdes, thanks!

The "eval" is not necessary at all:

variable="print - 'hello world'"
$variable

will print "hello world".

ksh has a fixed order of the operations it undertakes before finally executing the result on the commandline. "eval" restarts this process and evaluates the already processed commandline a second time. It works (somehow) analogous to derefencing a pointer in C:

# var1="Willy"
# var2="Tony"
# selector='$var1'
# print - $selector
$var1
# eval print - $selector
Willy
# selector='$var2'
# print - $selector
$var1
# eval print - $selector
Tony

The reason is: The shell gets the command line "print - $selector" and evaluates that (by expanding the variable with its content) to "print - $var1". The process would normally stop there, but in case of using "eval" it would now again try to evaluate its own result and in this case (since "$var1" will expand to the content of var1) end up with "print - Willy".

I hope this clarifies things.

Btw. I remember there was a REXX interpreter for AIX 3.2.5 (yep, that's been awhile), maybe it is possible to still get it from IBM. I doubt that it will be available for other Unixes, though.

bakunin

All,

We are talking REXX, right? $ is not allowable in vars in REXX, so what are we talking?

Both "eval" and "interpret" work in REXX, but they have different formats, so you need to look in the manual for your version of REXX. There are several versions such as:

PREXX - Personal REXX
Regina - Another Personal REXX
OO-REXX - Official OO Rexx version (good docs)

Once you install you will enter "rexx cmdfile" at command line or for OO rexx enter the OO shell and execute the project. You can actually use OO rexx either way.

To display on screen, via command line, the "say" command, similar to PHP "echo" is used. Not eval or interpret.

Actually your script looks more like a PHP or PERL script than REXX. Is that what you are trying to do?

Let us know what else to help.

OMR