The hush shell for GNO

This is a port of the hush shell to the GNO multitasking environment for the Apple IIgs. Hush is a Bourne/POSIX-style shell that was originally part of BusyBox. In general, it implements most of the features you would expect, although there are a few missing ones (such as tilde expansion and aliases).

Supported features include:

if/then/elif/else/fi conditionals
for/in/do/done loops
while loops
case/esac
functions
redirections (including specifying file descriptors)
here documents
arithmetic with $((...))
command substitution with backticks or $(...)
glob pattern expansion (including globbing across multiple directory levels)
command line editing with history and tab completion
job control
and much more...

The (useful) command line options are:

hush [-nxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]

These all behave similarly to other Bourne/POSIX-style shells (e.g. Bash). Run help within hush to get a list of built-in commands.

Installation

To use hush, you need GNO 2.0.6. Just copy the "hush" binary to a suitable location. (You may want to install it as /bin/sh to support portable scripts that expect a Bourne-type shell in that location).

Building

To build it, you also need ORCA/C 2.1.x and plenty of memory (8MB is enough). You also need to have a copy of the ltermcap library from GNO 2.0.4 installed as /usr/lib/libtermcap.204 (the GNO 2.0.6 version is broken and won't work). Run make or (if the source files don't have correct filetypes) make build. You should also be able to build it on modern *nix systems by running make, although this is meant mainly for testing purposes.

GNO-specific notes and known issues

$PATH is expected to be in the usual GNO format (searched backwards, with spaces as separators).
File descriptors 0, 1, and 2 appearing in shell operations like redirections are translated to 1, 2, and 3, respectively. This maintains compatibility with Unix shell scripts that expect these to be stdin, stdout, and stderr.
Glob expansion doesn't work with patterns containing : directory separators. Use / separators instead. Also, note that pattern matching is case-sensitive even though the filesystem is not.
Shell variable names are case-insensitive on GNO. This matches GNO's handling of environment variables.
In TMTerm, command-line editing operations can produce messed-up formatting.

Startup files

This version of hush will read commands from several files at startup, if they are present:

First, it runs commands from /etc/hushenv, then from $HOME/hushenv.
Next, if it is a login shell, it runs commands from /etc/profile, then from $HOME/hushprofile (if it is present) or $HOME/profile.
Finally, if it is an interactive shell, it runs commands from $HOME/hushrc.

(It also supports versions of the user startup files with names starting with ., which will be used preferentially if present, but these names are not compatible with ProDOS filesystems.)

The etc directory contains sample hushenv and profile scripts, suitable for installation in /etc or in your home directory.

License

Hush is licensed under the GNU General Public License version 2, contained in the file LICENSE. Some individual source files contain code licensed under other GPL-compatible permissive licenses. See the individual source files for full licensing details and copyright notices.