I am working on a script that is based on the parm will generate a DDL using db2look. Problem I am having is I do not want anything showing up on the screen while db2look is running.

I have found a solution, but it makes no sence to me what so ever. here is where I am looking out for you folks to help me understand why it is doing what it is doing.

Here is what I am getting:

1. Running db2look piping it out to a file
DDL Information going to a file, lines with '--' are going to my screen.

2. Now I am going to try to send std out to a file and not a screen

However, as expected my x file is empty and all of the info is in the xx file. But garbage still went to the screen.

3. My fingers did their own walking and wrote this

This gave me exactly what I need. DDL into a file, garbage in a dumpster.

Here is where my dilemma. Why all those lines with '--' are treated as an error While return code is still a BIG FAT ZERO? I would have never guessed it.

BTW. I am going to run sed command to clean up garbage file and then run a check on it. If it is empty, then there were no errors, if it is not empty...well, you guessed.

Thank you and remember. It is Friday and it is 5pm someplace. But don't ignore my question

but lines that begin with '--' are just comments, not errors.

He means that those messages are being written to stderr and not stdout as one would expect. Why IBM chose to do that is beyond me. You will have to ask them as to their reasoning.

Andy

This is standard practice to write the "payload" output to stdout and diagnostic messages to stderr so as not to mix two types of information. Many unix utilities work that way.

Bella, Andy is right on the money on what I meant. Bella, can you go smack someone over there for me?

Nick, if you are correct, then it is madness. If I haven't discovered that it is putting -- into the stderr and was performing an error check. It would be alarming on every entree even so there was no problem.

Not doubting you, but can you please provide some kind of document that talks about it. I have been reading UNIX book all day on it and haven't found a single references on this practice.

BTW. It does write this junk to stdout anyway.

I think I got it now. You expect stderr to return a non-zero RC if the file contains something. If I specify a non-existing db name, then the RC is non-zero and the file contains the same comments plus the error message.

If you say so.

Shell exit code is for status checks. Different output streams are used to separate program main output and diagnostic messages.

Certainly. Amazon.com: Unix Programming Environment (Prentice-Hall Software Series) (9780139376818): Brian W. Kernighan, Rob Pike: Books

I will get this book, but mean while. Following what you are saying dashes should only go to stderr, why do they show up in stdout as well?

The default stream for stderr goes to the console, unless you redirect it with 2> ...

Knut, I understand and know this. My point is. If dashes are treated as stderr, why do they still show up in stdout even so I do redirect it with 2>

This tells me that they are treated as stdout as well as stderr. And that is what drives me nuts I have enough problems my own split personality