Description:

Visiting /usr/lib/initcpio/install/systemd (or the equivalent file in the package source) in Emacs greatly confuses the syntax highlighting because of lines like:

4: local len=${#1} quotes=$'[\'"]' str=${!1}

Please consider changing this to the more readable and machine-parsable:

4: local len=${#1} quotes=[\'\"] str=${!1}

After this change, Emacs' syntax highlighting no longer treats the rest of the file as an unterminated string.

Similarly, on this line:

28: [[ -z $rule || $rule = @(+([[:space:]])|#*) ]] && continue

Emacs syntax highlighting treats this part as a comment:

#*) ]] && continue

Please consider changing this line to:

28: [[ -z $rule || $rule = "@(+([[:space:]])|#*)" ]] && continue

if only to make syntax highlighters happy.

Finally, on line 33, there appears to be a syntax error (found by Emacs Flycheck):

/bin/bash: line 33: syntax error near unexpected token `('
/bin/bash: line 33: ` RUN@({program}|+)|IMPORT{program}|ENV{REMOVE_CMD})'

I'm guessing that this wasn't caught before is that hooks are sourced, not executed, by mkinitcpio.
I know that there are subtle differences in how sourced and executed scripts are handled, but I don't think it is wise to rely on those for correct operation, in paticular if they limit the use of tools like syntax checkers.

Additional info:
* package version(s)
mkinitcpio 18-2
* config and/or log files etc.


Steps to reproduce:
$ echo $SHELL
/bin/bash
$ bash /usr/lib/initcpio/install/systemd
bash /usr/lib/initcpio/install/systemd
/usr/lib/initcpio/install/systemd: line 33: syntax error near unexpected token `('
/usr/lib/initcpio/install/systemd: line 33: ` RUN@({program}|+)|IMPORT{program}|ENV{REMOVE_CMD})'
$ echo $?
2
$ . /usr/lib/initcpio/install/systemd
$ echo $?
0
(or use Emacs with Flycheck)