Re: Builtin command echo does not work properly.

[Eric Blake]

> 
> Description:
>         The builtin command echo [-neE] [arg ...] does not work properly
> 
> Repeat-By:
>         Enter:
>         echo -E "\ttext"
>         Expected result:
>         \ttext
>         Result:
>         -E      text

Not a bug.  POSIX requires that echo prints everything without regards
to options, with escape sequences active.  If you are using bash in
a manner specified by POSIX, such as invoking it by the name /bin/sh,
this is the behavior you should expect.  However, there is also the
xpg_echo option in shopt which controls this somewhat.

For example, I just did:
$ echo -E "\ttext" $BASH_VERSION $0
\ttext 3.1.14(4)-release /bin/bash
$ shopt xpg_echo
xpg_echo        off


> Fix:
>         Use /usr/bin/echo to work around this problem.

/usr/bin/echo from coreutils is not yet fully POSIX compliant, which is why
it will accept options even when bash won't.

-- 
Eric Blake