Support Mac platforms

[akerbos]

Need to get rid of some binary GNU dependencies, provide a start script and test for "hidden" incompatibilities.

Since I don't have any Mac workstations, input and pull requests are appreciated.

[reitzig]

GNU dependencies were removed back then for #51; unclear if there's any work to do. Test on a Mac!

[samcarter]

ltx2any works mostly just fine on mac, the only hiccup is that the readlink version from mac doesn't know the -e option (see e.g. https://blog.game-changing.de/being-different-for-the-sake-of-being-different-subtle-differences-within-command-line-tools/ )

For my personal use, I replaced readlink with greadlink:

set -eu

script_path="$(greadlink -e "${BASH_SOURCE[0]}")"

ruby "$(dirname "${script_path}")/ltx2any.rb" "$@"

(no idea if there is a better solution)

tested with:

• macOS 14.5.1
• ruby 3.3.1 installed via homebrew
• greadlink 9.5 also installed via homebrew

[reitzig]

Thanks, hope that helps future visitors!

Alternatives I can think of:

• Somewhere on the PATH, put your own shell script that explicitly calls ruby /your/path/to/ltx2any.rb "${@}".
• Add shebang #!/usr/bin/env ruby to ltx2any.rb and symlink it directly, avoiding the intermediate shell script.
  ⚠️ Requires dependencies to be installed at system level (don't understand why, won't investigate) -- can't recommend!
• IIRC: Transform macOS into a (somewhat) usable system by brew install coreutils 😉