Re: Conditional expression problem: both "-a file" and "! -a file" return true

[Paul Jarc]

Eric Blake <ebb9@byu.net> wrote:
> But the RATIONALE (XCU line 35443) states that "The ! operator has higher
> precedence than the -a operator, and the -a operator has higher precedence
> than the -o operator."  Therefore, when -a is defined as a unary operator,
> an XSI compliant test is required to return failure for "test ! -a file"
> if file exists.  Bash got this wrong, so indeed it is a bug.

No, I think that quote only says that this:
  ! 1 -a 2
is the same as this:
  ( ! 1 ) -a 2
and not this:
  ! ( 1 -a 2 )

It doesn't give us any guidance for deciding whether ! is an operator
or operand in any particular case.


paul