Update sendme.sh to support Windows operating system

[neuralpain]

I wasn't satisfied with the one-liner PowerShell code I shared in issue #84, so I attempted to update the main install script at iroh.computer/sendme.sh. The code below is the proposed update which was tested using Git Bash (MINGW64). Another test can be done before officially updating.

#!/bin/sh
# Copyright 2023 n0. All rights reserved. Dual MIT/Apache license.
# Windows support provided by neuralpain.

set -e

repo="n0-computer/sendme"
release_url="https://api.github.com/repos/$repo/releases/latest"

if [ "$OS" = "Windows_NT" ]; then
  target="windows-x86_64"
else
  case $(uname -sm) in
  "Darwin x86_64") target="darwin-x86_64" ;;
  "Darwin arm64") target="darwin-aarch64" ;;
  "Linux x86_64") target="linux-x86_64" ;;
  "Linux arm64" | "Linux aarch64") target="linux-aarch64" ;;
  *) target="linux-x86_64" ;;
  esac
fi

echo "Downloading $repo for $target"
release_target_url=$(
  curl -s "$release_url" |
    grep "browser_download_url" |
    grep "$target" |
    sed -re 's/.*: "([^"]+)".*/\1/'
)

if [[ "$release_target_url" =~ \.zip$ ]]; then
  release_name=$(
    curl -s "$release_url" |
      grep "name" |
      grep "$target" |
      sed -re 's/.*: "([^"]+)".*/\1/'
  )
  curl -sL "$release_target_url" -O | unzip -oq $release_name
else
  curl -sL "$release_target_url" | tar xz
fi

[neuralpain]

I wasn't satisfied with the one-liner PowerShell code I shared...

This does not mean that the PowerShell code is obsolete. Not every Windows OS is set up with a Unix-like shell environment by default; and for that reason the PowerShell one-liner would be the preferred method of installation. However, I'd like to think of this as added versatility for the more capable power users out there.

if [[ "$release_target_url" =~ \.zip$ ]]

Since the Windows release is the only package which uses a .zip extension, this shouldn't cause any issues during installation.

[neuralpain]

Disregard for now; I'll push an update via PR. I'm running a couple more tests.