[Toybox] making ./configure executable.

[Rob Landley]

On 02/05/2018 04:01 PM, Robert Thompson wrote:
> It seems that the single-equals is POSIX, while the double-equals is a
> bash extension that at one point bash preferred and extended the match
> behavior of.
> 
> But, the bash manpage now documents double-equals  (when in the
> context of the builtin test or its '[' alias) as equivalent to
> single-equals.

I researched all this crud at one point, but it was a few years ago now. :)

> The manpage notes that when using test (rather than '['), one should
> always use single-equals, due to POSIX compatibility issues, in case
> the script gets run by a shell without a builtin test.
> 
> Bash has another extended test, '[[', which does significantly
> different, and expanded, things, but its behavior was inconsistent
> across bash versions the last time it was relevant to my work.
> 
> Apparently bash's interpretation of single-equals isn't always exactly
> POSIX-standard, depending on which bash settings are in effect. A
> quick skim shows that it may or may not be case-insensitive, may or
> may not be glob-active (older version), *is* glob-active (newer
> versions, with caveats?)...
> 
> dash's behavior isn't saying "unknown operator '['". It's saying
> "builtin-test-via-left-square-bracket: unknown operator '=='". I think
> it's just phrasing it really poorly due to overly simplistic
> backtracking in its parser (most recent symbol being assumed to be the
> cause of the error, thus printed).

Dash is crap. The switch to dash was because Ubuntu wanted to run its
init scripts faster and thought changing all the init scripts to start
with #!/bin/dash was too intrusive a change. No really:

  https://wiki.ubuntu.com/DashAsBinSh

This broke (among other things) the Linux kernel build. (Bash was the
first program Linux ever ran, Linus extended his term program to run
bash specifically. /bin/sh being bash was the one thing all Linux
distros agreed on, until Ubuntu did a stupid.)

Then, of course, the redirect didn't speed init up enough so they went
down the parallelizing route and created "upstart", but didn't back out
the /bin/sh change because that would be admitting they made a mistake.
(They did relent enough to change the default so user accounts would
have bash as their default shell in /etc/passwd.)

Yes, it is a pet peeve of mine. :)

Rob