Add install script and update install instructions (#324)

* add install script

* update install instructions

* Update install.sh
Co-Authored-By: Maurizio Branca <m.branca@arduino.cc>

* Update install.sh
Co-Authored-By: per1234 <accounts@perglass.com>

* Update README.md
Co-Authored-By: per1234 <accounts@perglass.com>

.editorconfig

@@ -18,3 +18,7 @@ indent_size = 4
 [*.yml,*.tmpl]
 indent_style = space
 indent_size = 2
+
+[*.sh]
+indent_style = tab
+indent_size = 4

install.sh

+#!/bin/sh
+
+# The original version of this script is licensed under the MIT license.
+# See https://github.com/Masterminds/glide/blob/master/LICENSE for more details
+# and copyright notice.
+
+PROJECT_NAME="arduino-cli"
+
+# BINDIR represents the local bin location, defaults to ./bin.
+LBINDIR=""
+DEFAULT_BINDIR="$PWD/bin"
+
+fail() {
+	echo "$1"
+	exit 1
+}
+
+initDestination() {
+	if [ -n "$BINDIR" ]; then
+		if [ ! -d "$BINDIR" ]; then
+			fail "$BINDIR "'($BINDIR)'" folder not found. Please create it before continuing."
+		fi
+		LBINDIR="$BINDIR"
+	else
+		if [ ! -d "$DEFAULT_BINDIR" ]; then
+		mkdir "$DEFAULT_BINDIR"
+		fi
+		LBINDIR="$DEFAULT_BINDIR"
+	fi
+	echo "Installing in $LBINDIR"
+}
+
+initArch() {
+	ARCH=$(uname -m)
+	case $ARCH in
+		armv5*) ARCH="armv5";;
+		armv6*) ARCH="armv6";;
+		armv7*) ARCH="ARM";;
+		aarch64) ARCH="ARM64";;
+		x86) ARCH="32bit";;
+		x86_64) ARCH="64bit";;
+		i686) ARCH="32bit";;
+		i386) ARCH="32bit";;
+	esac
+	echo "ARCH=$ARCH"
+}
+
+initOS() {
+	OS=$(uname -s)
+	case "$OS" in
+		Linux*) OS='Linux' ;;
+		Darwin*) OS='macOS' ;;
+		MINGW*) OS='Windows';;
+		MSYS*) OS='Windows';;
+	esac
+	echo "OS=$OS"
+}
+
+initDownloadTool() {
+	if type "curl" > /dev/null; then
+		DOWNLOAD_TOOL="curl"
+	elif type "wget" > /dev/null; then
+		DOWNLOAD_TOOL="wget"
+	else
+		fail "You need curl or wget as download tool. Please install it first before continuing"
+	fi
+	echo "Using $DOWNLOAD_TOOL as download tool"
+}
+
+get() {
+	local url="$2"
+	local body
+	local httpStatusCode
+	echo "Getting $url"
+	if [ "$DOWNLOAD_TOOL" = "curl" ]; then
+		httpResponse=$(curl -sL --write-out HTTPSTATUS:%{http_code} "$url")
+		httpStatusCode=$(echo $httpResponse | tr -d '\n' | sed -e 's/.*HTTPSTATUS://')
+		body=$(echo "$httpResponse" | sed -e 's/HTTPSTATUS\:.*//g')
+	elif [ "$DOWNLOAD_TOOL" = "wget" ]; then
+		tmpFile=$(mktemp)
+		body=$(wget --server-response --content-on-error -q -O - "$url" 2> $tmpFile || true)
+		httpStatusCode=$(cat $tmpFile | awk '/^  HTTP/{print $2}')
+	fi
+	if [ "$httpStatusCode" != 200 ]; then
+		echo "Request failed with HTTP status code $httpStatusCode"
+		fail "Body: $body"
+	fi
+	eval "$1='$body'"
+}
+
+getFile() {
+	local url="$1"
+	local filePath="$2"
+	if [ "$DOWNLOAD_TOOL" = "curl" ]; then
+		httpStatusCode=$(curl -s -w '%{http_code}' -L "$url" -o "$filePath")
+	elif [ "$DOWNLOAD_TOOL" = "wget" ]; then
+		body=$(wget --server-response --content-on-error -q -O "$filePath" "$url")
+		httpStatusCode=$(cat $tmpFile | awk '/^  HTTP/{print $2}')
+	fi
+	echo "$httpStatusCode"
+}
+
+downloadFile() {
+	get TAG_JSON https://api.github.com/repos/arduino/arduino-cli/releases/latest
+	TAG=$(echo $TAG_JSON | python -c 'import json,sys;obj=json.load(sys.stdin, strict=False);sys.stdout.write(obj["tag_name"])')
+	echo "TAG=$TAG"
+	#  arduino-cli_0.4.0-rc1_Linux_64bit.tar.gz
+	CLI_DIST="arduino-cli_${TAG}_${OS}_${ARCH}.tar.gz"
+	echo "CLI_DIST=$CLI_DIST"
+	DOWNLOAD_URL="https://downloads.arduino.cc/arduino-cli/$CLI_DIST"
+	CLI_TMP_FILE="/tmp/$CLI_DIST"
+	echo "Downloading $DOWNLOAD_URL"
+	httpStatusCode=$(getFile "$DOWNLOAD_URL" "$CLI_TMP_FILE")
+	if [ "$httpStatusCode" -ne 200 ]; then
+		echo "Did not find a release for your system: $OS $ARCH"
+		echo "Trying to find a release using the GitHub API."
+		LATEST_RELEASE_URL="https://api.github.com/repos/arduino/$PROJECT_NAME/releases/tags/$TAG"
+		echo "LATEST_RELEASE_URL=$LATEST_RELEASE_URL"
+		get LATEST_RELEASE_JSON $LATEST_RELEASE_URL
+		# || true forces this command to not catch error if grep does not find anything
+		DOWNLOAD_URL=$(echo "$LATEST_RELEASE_JSON" | grep 'browser_' | cut -d\" -f4 | grep "$CLI_DIST") || true
+		if [ -z "$DOWNLOAD_URL" ]; then
+			echo "Sorry, we dont have a dist for your system: $OS $ARCH"
+			fail "You can request one here: https://github.com/Arduino/$PROJECT_NAME/issues"
+		else
+			echo "Downloading $DOWNLOAD_URL"
+			getFile "$DOWNLOAD_URL" "$CLI_TMP_FILE"
+		fi
+	fi
+}
+
+installFile() {
+	CLI_TMP="/tmp/$PROJECT_NAME"
+	mkdir -p "$CLI_TMP"
+	tar xf "$CLI_TMP_FILE" -C "$CLI_TMP"
+	CLI_TMP_BIN="$CLI_TMP/$PROJECT_NAME"
+	cp "$CLI_TMP_BIN" "$LBINDIR"
+	rm -rf $CLI_TMP
+	rm -f $CLI_TMP_FILE
+}
+
+bye() {
+	result=$?
+	if [ "$result" != "0" ]; then
+		echo "Failed to install $PROJECT_NAME"
+	fi
+	exit $result
+}
+
+testVersion() {
+	set +e
+	CLI="$(which $PROJECT_NAME)"
+	if [ "$?" = "1" ]; then
+		fail "$PROJECT_NAME not found. Did you add "$LBINDIR" to your "'$PATH?'
+	fi
+	if [ $CLI != "$LBINDIR/$PROJECT_NAME" ]; then
+		fail "An existing $PROJECT_NAME was found at $CLI. Please prepend "$LBINDIR" to your "'$PATH'" or remove the existing one."
+	fi
+	set -e
+	CLI_VERSION=$($PROJECT_NAME version)
+	echo "$CLI_VERSION installed successfully"
+}
+
+
+# Execution
+
+#Stop execution on any error
+trap "bye" EXIT
+initDestination
+set -e
+initArch
+initOS
+initDownloadTool
+downloadFile
+installFile
+testVersion