echo "$0: run all 'demo.sh' scripts using libdemo"

    echo "$0: run all 'demo.sh' scripts in order"

    echo "  -a|--auto: run in automatic mode"

    echo "  -a|--auto: run in automatic mode (no pausing)"

or run one particular demo using

or run one particular demo using `./<xx-demo-name>/demo.sh`.

```console
./<xx-demo-name>/demo.sh
```

⚠ The demos build a number obscure variants of packages that are not provided by https://cache.nixos.org/, so this might take a long time the first time you run them.
 Once the packages are present in the Nix store the scripts run in seconds (in automatic mode).

⚠ The container-related demos use [rootless Podman](https://github.com/containers/podman/blob/main/docs/tutorials/rootless_tutorial.md), which needs some configuration files.
If they don't exist yet they will be created in `~/.config/containers/` and will not removed. The scripts do make a best-effort attempt at removing any containers that are created.
Rootless Podman has some special requirements; most of them are provided by Nix, but e.g. [`/etc/subuid` and `/etc/subgid` configuration](https://github.com/containers/podman/blob/main/docs/tutorials/rootless_tutorial.md#etcsubuid-and-etcsubgid-configuration) must be fixed by an administrator.

* [01-nix-run](01-nix-run/demo.sh): Basic running of Nix packages as an alternative to using a Docker container.
* [02-nix-build](02-nix-build/demo.sh): Using Nix to build packages and get a development environment 'for free'.
* [03-nix-container](03-nix-container/demo.sh): Using Nix to build containers and run them using [rootless Podman](https://github.com/containers/podman/blob/main/docs/tutorials/rootless_tutorial.md).
* [04-cmake-and-cross](04-cmake-and-cross/demo.sh): Building packages that use CMake, and cross-compile them for different architectures and static executables. Doing the same with emulation.

The various demos will show you how to:
* [01-nix-run](01-nix-run/demo.sh): Run Nix packages as an alternative to using a [Docker container](https://www.docker.com/).
* [02-nix-build](02-nix-build/demo.sh): Use Nix to build packages and get a development environment 'for free'.
* [03-nix-container](03-nix-container/demo.sh): Use Nix to build containers and run them using rootless Podman.
* [04-cmake-and-cross](04-cmake-and-cross/demo.sh): Build packages that use [CMake](https://cmake.org/), and cross-compile them for different architectures and static executables.

* [06-windows-wine](06-windows-wine/demo.sh): Build a static Windows binary and run it through wine. Here be dragons.

* [06-windows-wine](06-windows-wine/demo.sh): Build a static Windows binary and run it through [wine](https://www.winehq.org/). Here be dragons.

./demo-full.sh: run all 'demo.sh' scripts using libdemo

./demo-full.sh: run all 'demo.sh' scripts in order

  -a|--auto: run in automatic mode

  -a|--auto: run in automatic mode (no pausing)

Additional functions are provided that can be used in commands:
* `pygmentize`: Wrapper around [pygmentize](https://pygments.org/docs/cmdline/).
* `tiv`: Wrapper around [tiv](https://github.com/stefanhaustein/TerminalImageViewer).