awk: how can I print out a message to the screen when redirecting the output to file.

quanba · 03-15-2010, 11:06 PM

Hi there,

I have a problem when using awk:

e.g: awk '{processing text}' File1 > File2

But when I'm processing the File1, I want to print out some messages to the screen (not the File2). How can I do that?

p/s: thanks for your help.

crts · 03-15-2010, 11:31 PM

Quote:

Originally Posted by quanba

Hi there,

I have a problem when using awk:

e.g: awk '{processing text}' File1 > File2

But when I'm processing the File1, I want to print out some messages to the screen (not the File2). How can I do that?

p/s: thanks for your help.

Well, then just do not redirect it to File2.

Code:

awk '{processing text}' File1

If you want to print on screen and redirect to File2 then

Code:

awk '{processing text}' File1 | tee File2

Tinkster · 03-16-2010, 12:00 AM

Quote:

Originally Posted by quanba

Hi there,

I have a problem when using awk:

e.g: awk '{processing text}' File1 > File2

But when I'm processing the File1, I want to print out some messages to the screen (not the File2). How can I do that?

p/s: thanks for your help.

Code:

awk '{print "processing text: " FILENAME > "/dev/stderr"}' File1 > File2

should work

Tinkster · 03-18-2010, 02:38 PM

And does this work for you? Some feedback would be appreciated...

quanba · 03-28-2010, 01:19 PM

Thanks Tinkster, sorry for being overloaded and forgot about this thread. Your solution works greatly. I am wondering if it's unusual if we print out a message to /etc/stderr in case it's not an error (just a result of some action)?

Tinkster · 03-28-2010, 05:25 PM

Not sure I quite understand your question; it's not uncommon to print
informational stuff (in other words status messages and the like) out
to stderr. Normally stdout is just for "payload" of a process, stderr
for anything else.

Cheers,
Tink