Re: psql -L log errors

On Wed, Mar 11, 2015 at 08:47:13AM -0300, Felipe Santos wrote:

  When you are using the "--log-file" clause, you are telling the psql to
  redirect the normal output to the file indicated, but the error output
  keeps being sent to the standard output device.
  To redirect the error output you have to append it to the file you're
  logging into.
  To do that, do the following (both Win and Linux, replace the psql
  arguments ofr yours) :
  psql -U sample_user -W -c "select * from foo;" sample_database
  --log-file=sample_file.txt 2>> sample_file.txt

Thank you for your answer, Felipe.
Why the error output keeps being sent to the standard output device?
Does it get sense to redirect only stdout to file when "--log-file" is used?
Why not to also redirect stderr? Could the dup2() fuction be used for that?
Or even better could the stderr be "teed" both to the log file and to the standard output device?

Thanks
Hans

http://stackoverflow.com/questions/14543443/in-c-how-do-you-redirect-stdin-stdout-stderr-to-files-when-making-an-execvp-or
https://github.com/goj/coreutils/blob/rm-d/src/tee.c