Re: `$x` adds single quotes during interpolation under Wrong Circumstances

[Chet Ramey]

philo vivero wrote:

> On Fri, 2004-04-02 at 07:14, Paul Jarc wrote:
>
> > philo vivero <phiviv@hacklab.net> wrote:
> >
> > > How can I make "echo $a" return "*.log*" if there is a file called
> > > "install.log.syslog" in the cwd?
> >
> > echo "$a"
>
>
> echo "$a" != echo $a -- this is not pedantic.
>
> It makes a particular function impossible to write (of course I could do
> kludgery by changing CWD to some directory that I know doesn't contain
> certain files, but I hope you don't recommend this).
>
> I'm hoping you can tell me that there's a good reason that this:
>
> a=\*.log\*
> echo $a
>
> does a double-expansion. First $a is expanded out to "*.log*" *THEN*
> that is further expanded to install.log.syslog

There is no `double expansion'.

The rhs of the assignment statement is expanded, resulting in "*.log*".
The backslashes are removed as part of quote removal.  This is as you
have observed.

When $a is expanded, the results are available for pathname expansion,
if unquoted.  This is how sh has always behaved.

Posix explains the process pretty well:

http://www.opengroup.org/onlinepubs/007904975/utilities/xcu_chap02.html#tag_02_06

> If this is a
> feature-not-a-bug I really don't mind dropping this issue. But I still
> feel it's a bug. Would you accept a patch?

No.  The incompatibility and breakage is not worth it.

Chet