Re: POSIX shell specification insight requested

[Colin Watson <cjwatson@debian.org>]

On Tue, Mar 02, 2004 at 01:04:43PM -0500, Branden Robinson wrote:
> Is the following construction POSIXly correct?
> 
> foo=$(cat <<EOF
> Foo bar baz quux.
> EOF)
> 
> ash (and dash, which is derived from ash) choke on this, and seem to
> ignore everything on the same line as, but after, the here-document
> terminator word.
> 
> bash (--posix) and (pd)ksh have no problem with it.
> 
> I would be most grateful if someone access to the POSIX spec could
> provide some insight into this.

The current version of POSIX is available here:

  http://www.opengroup.org/onlinepubs/007904975/nfindex.html

It says, in
http://www.opengroup.org/onlinepubs/007904975/utilities/xcu_chap02.html#tag_02_07_04:

  The here-document shall be treated as a single word that begins after
  the next <newline> and continues until there is a line containing only
  the delimiter and a <newline>, with no <blank>s in between.

Thus I think I agree with dash here. I suggest this alternative
construction:

foo=$(cat <<EOF
Foo bar baz quux.
EOF
)

Cheers,

-- 
Colin Watson                                  [cjwatson@flatline.org.uk]