[erlehmann_]

The following sentence about my redo implementation is wrong:

> In 2014, Nils Dagsson Moskopp re-implemented Pennarun redo, retargetting it at the Bourne Again shell and BusyBox.

I targeted the Bourne Shell (sh), not the Bourne Again Shell (bash). Also, my redo implementation contains redo-dot that paints a dependency-tree – I have not seen this otherwere.

[JdeBP]

You only put /bin/sh as the interpreter. You still used quite a number of Bourne Again shell constructs in the scripts themselves. Some are not in POSIX sh and utilities, some are not in the Bourne shell. (The Bourne shell is not conformant with POSIX sh, so targetting POSIX sh is not the same as targetting the Bourne shell.)

These include amongst others local, $(), >&-, the -a and -o operators to test, and command. (You also failed to guard against variables expanding to operators in the test command, but that is a common general error rather than a Bashism.)

Beware of testing against /bin/sh, even the BusyBox one, and assuming that that means POSIX compliance, let alone Bourne shell compatibility. Even the OpenBSD Korn shell running as /bin/sh or the Debian Almquist shell running as /bin/sh will silently admit some non-POSIX constructs.

[erlehmann_]

While you are right about POSIX problems (like using “local”) I actually targeted Dash and older versions of BusyBox – not Bash.

I plan to work on POSIX compatibility for my redo implementation.