Re: POSIX shell specification insight requested

[Humberto Massa <humberto.massa@almg.gov.br>]

Manoj Srivastava wrote:

> On Tue, 2 Mar 2004 13:04:43 -0500, Branden Robinson <branden@debian.org>
> said: 
>
>  
>
> > Is the following construction POSIXly correct?  foo=$(cat <<EOF Foo
> > bar baz quux.  EOF)
> >    
>
>  
>
> ======================================================================
> ISO/IEC 9945-2:1993(E)  Information Technology -- POSIX
> IEEE Std 1003.2-1993    Part 2: Sheel and utilities
>
> § 3.6.3  Command substitution
>
> ...
>
> lines 474-477
>
> Within the $(command) form, all characters following the open
> parenthesis to the  matching closing parenthesis constitute the
> /command/. Any valid shell script can be used for /command/, except
>
>  -- A script consisting solely of redirections produces unspecified
>     results 
> ======================================================================
>  
/solely/ being the key word here, as in:

foo=$(<a >b 2>&1)

> 	The here document is a redirection, hence the reults of that
> command substitution are unspecified.
>
> 	manoj
>  
nope. this:
foo=$(cat <<EOF
bab
cac
EOF)

is wrong 'cause the EOF should be alone in its line, so

foo=$(cat <<EOF)
bab
cac
EOF

should work, and so should

foo=$(cat <<EOF
bab
cac
EOF
)

the example in the posix spec says this works:

cat << eof1; cat << eof2
Hello
eof1
Manoj
eof2


[]s, HTH
Massa