docker/docker — pull request #7887 by rhatdan (2014-09-04 19:32:50+00:00)
Title: --help option and help command should print to stdout not stderr

--help and help are successful commands so output should not go to error.

QE teams have requested this change, also users doing docker help | less
or docker run --help | less would expect this to work.

Usage statement should only be printed when the user asks for it.
Errors should print error message and then suggest the docker COMMAND --help
command to see usage information.

The current behaviour causes the user to have to search for the error message
and sometimes scrolls right off the screen. For example a error on a
"docker run" command is very difficult to diagnose.

Finally erros should always exit with a non 0 exit code, if the user
makes a CLI error.

Docker-DCO-1.1-Signed-off-by: Dan Walsh (github: rhatdan)

Docker-DCO-1.1-Signed-off-by: Dan Walsh (github: rhatdan)