!$ works with `` but not $()

[Ralph Corderoy]

Binary package hint: bash

This is on 10.04 and also with upstream's pure bash 4.2 with no Debian or Ubuntu patches.

    $ echo bar >foo
    $ >bar
    $ ls `cat foo`
    bar
    $ wc !$
    wc `cat foo`
    0 0 0 bar
    $ ls $(cat foo)
    bar
    $ wc !$
    wc )
    -bash: syntax error near unexpected token `)'
    $ ls $(<foo)
    bar
    $ wc !$
    wc )
    -bash: syntax error near unexpected token `)'
    $

I'd expect !$ to consider the last word to be $(...) just as it is happy with `...`. zsh does.

[Ralph Corderoy (ralph-inputplus)]

bash's upstream maintainer Chet Ramey confirms the bug and says it will be fixed in the next release. http://lists.gnu.org/archive/html/bug-bash/2011-06/msg00003.html