Subject: Re: bug#19604: echo --help does not work

From: Bernhard Voelker <[email-masked]>
Date: Fri, 16 Jan 2015 10:49:06 +0100

On 01/15/2015 04:55 PM, prateek goyal wrote:
> So even if I execute following command, it gives same result:

> prateek@prateek-pc:~/Documents/awk$ env POSIXLY_CORRECT=1 echo --help
> --help

That is exactly what Eric said before: POSIX mandates to literally
output the string "--help" - which coreutils' echo does if the variable
POSIXLY_CORRECT is set.  Otherwise, the implementation extends the
functionality and adheres to GNU standards which mandates to honor
the "--help" option to output the usage message:

   $ env --unset=POSIXLY_CORRECT echo --help
   Usage: ...

Maybe you were confused by the use of the 'env' utility.
You'll get the same by specifying the echo with it's absolute path:

   $ which echo
   /usr/bin/echo
   $ unset POSIXLY_CORRECT
   $ /usr/bin/echo --help
   Usage: [...]

Have a nice day,
Berny