ksh problem

[Ricky Tang]

I wonder how to trace a ksh script line by line but without actually executing the commands.

[Thierry Poels_1]

hi,
"ksh -n script" does a syntax check of your script without executing it; not perfect, but something to begin with ;)
regards,
Thierry.

[Carsten Krege]

If you put a "set -x" at the beginning of a script, you will get a trace of the script to stdout. Of course the commands will still be executed. Here is an example:

#!/usr/bin/ksh
set -x

A="Hello World!"
echo $A


The output when executing the script is:

+ A=Hello World!
+ echo Hello World!
Hello World!


Carsten

[Ricky Tang]

Hi Carsten,

The point is I do not want to
execute the script, just parsing it. Any idea?

[Laurent Paumier]

If you want to check your script for syntax errors, use the -n option (as stated by Thierry). If you just want to see the statements without executing them, use the 'cat' command ;)

[Ricky Tang]

Maybe I should make my question more clearly.
What I want is something
like a debugger which can
show me the actual command
after filename and variable
expansions; but without
actually executing the
command

[Printaporn_1]

I think we don't have that debug tool

[Paula J Frazer-Campbell]

Hi Ricky

What you could do is create a temp dir with appropiate file in it and point your script at this area, this of course depends upon your script.

Paula

[Fred Martin_1]

No real way to do that, other than what's already been said. But one place I worked always did this with scripts (and, c programs for that matter):

At the head of the script, define the path to the data files:

datapth=/db/test
#datapth=/db/real

The path to the "live" data is commented-out.

All references in the script use the variable to point to the data.

So, while you write and debug your script you are using test data.

Then, to put the script into production, swap the comment tothe other path setting.

Fred

[Jack Werner]

You can create a function like
echodo ( echo "$*" }

You can assign a variable x = "echodo" and prefix every command with the $x variable. To turn it off just set x="" (null) and commands will run.