Update install script & use latest version by default

README.md

@@ -13,16 +13,19 @@ Then, install DockerC with the following command:
 
 ```bash
 /bin/sh -c "$(curl -fsSL https://raw.githubusercontent.com/matiboux/dockerc/HEAD/install.sh)"
+# Usage: /bin/sh -c "$(cat install.sh)" -- [--help] [--install-dir <dir>] [tag]
 ```
 
 Take a look at the [install.sh](install.sh) script to see what it does.
 
-If you get the error `Failure writing output to destination`,
-try to run the command again with `sudo` or grant yourself write permissions to install directory (`/usr/local/bin` by default).
+If you get a cURL error, check the following:
 
-```bash
-sudo /bin/sh -c "$(curl -fsSL https://raw.githubusercontent.com/matiboux/dockerc/HEAD/install.sh)"
-```
+- cURL error `22`: Requested tag was not found. Verify your network and that the tag exists.
+
+- cURL error `23`: Failed to install DockerC. Verify your permissions in the install directory or try to run the command again with `sudo`.
+  ```bash
+  sudo /bin/sh -c "$(curl -fsSL https://raw.githubusercontent.com/matiboux/dockerc/HEAD/install.sh)"
+  ```
 
 
 ## Usage

dockerc

@@ -240,14 +240,7 @@ fi
 INSTALL_TAG=''
 if [ -n "$DOCKERC_INSTALL_TAG" ]; then
 	# Use from argument or environment variable
-	if
-		[ "$DOCKERC_INSTALL_TAG" = 'HEAD' ] || [ "$DOCKERC_INSTALL_TAG" = 'head' ] ||
-		[ "$DOCKERC_INSTALL_TAG" = '.' ] || [ "$DOCKERC_INSTALL_TAG" = '-' ]
-	then
-		INSTALL_TAG='HEAD'
-	else
-		INSTALL_TAG="$DOCKERC_INSTALL_TAG"
-	fi
+	INSTALL_TAG="$DOCKERC_INSTALL_TAG"
 fi
 
 DOCKER_PRESET=''
@@ -492,12 +485,14 @@ get_latest_version() {
 	)
 
 	if [ -n "$LATEST_VERSION_JSON" ]; then
+		# Extract version from matched string
+		# Remove `"tag_name": "` (13 characters) and `",` (2 characters)
 		if [ "$(uname -s)" = 'Darwin' ]; then
 			# MacOS
-			LATEST_VERSION="${LATEST_VERSION_JSON:14:$((${#LATEST_VERSION_JSON}-14-2))}"
+			LATEST_VERSION="${LATEST_VERSION_JSON:13:$((${#LATEST_VERSION_JSON}-13-2))}"
 		else
 			# Linux
-			LATEST_VERSION=$(expr substr "$LATEST_VERSION_JSON" $(expr 1 + 14) $(expr length "$LATEST_VERSION_JSON" - 14 - 2))
+			LATEST_VERSION=$(expr substr "$LATEST_VERSION_JSON" $(expr 1 + 13) $(expr length "$LATEST_VERSION_JSON" - 13 - 2))
 		fi
 
 		echo "$LATEST_VERSION"
@@ -512,7 +507,9 @@ if [ "$DOCKERC_PRINT_VERSION" = 'true' ]; then
 
 		if [ "$DRY_RUN" = 'false' ]; then
 			LATEST_VERSION=$(get_latest_version)
-			if [ "$VERSION" != "$LATEST_VERSION" ]; then
+			if [ -z "$LATEST_VERSION" ]; then
+				echo 'Notice: Failed to get DockerC latest version.' >&2
+			elif [ "$VERSION" != "$LATEST_VERSION" ]; then
 				echo "Notice: DockerC is not up to date, latest version is $LATEST_VERSION!" >&2
 			fi
 		fi
@@ -528,29 +525,24 @@ fi
 if [ "$UPDATE" = 'true' ]; then
 	# Update DockerC & exit
 
-	if [ ! -d "$INSTALL_DIR" ]; then
-		echo 'Error: Install directory does not exist.' >&2
-		exit 1
-	fi
-
-	if [ -z "$INSTALL_TAG" ]; then
-		# Default install tag is latest released version
-		INSTALL_TAG="$(get_latest_version)"
+	INSTALL_TAG_ARG=''
+	if [ -n "$INSTALL_TAG" ]; then
+		INSTALL_TAG_ARG=" \"$INSTALL_TAG\""
 	fi
 
 	if [ "$QUIET" = 'false' ]; then
 		# Print install script command
 		if [ "$DOCKERC_FIRST_NEWLINE" != 'false' ]; then
 			echo ''
 		fi
-		echo "> curl -fsSL \"https://raw.githubusercontent.com/matiboux/dockerc/HEAD/install.sh\" | /bin/sh -s -- \"${INSTALL_DIR}\" \"${INSTALL_TAG}\""
+		echo "> curl -fsSL \"https://raw.githubusercontent.com/matiboux/dockerc/HEAD/install.sh\" | /bin/sh -s -- --install-dir \"${INSTALL_DIR}\"${INSTALL_TAG_ARG}"
 		echo ''
 	fi
 
 	if [ "$DRY_RUN" = 'false' ]; then
 		# Run install script command
 		echo "Updating DockerC to ${INSTALL_TAG}..."
-		exec sh -c "curl -fsSL \"https://raw.githubusercontent.com/matiboux/dockerc/HEAD/install.sh\" | /bin/sh -s -- \"${INSTALL_DIR}\" \"${INSTALL_TAG}\""
+		exec sh -c "curl -fsSL \"https://raw.githubusercontent.com/matiboux/dockerc/HEAD/install.sh\" | /bin/sh -s -- --install-dir \"${INSTALL_DIR}\"${INSTALL_TAG_ARG}"
 	fi
 
 	exit ${ERROR_CODE:-0}

install.sh

@@ -8,79 +8,135 @@
 # This project is not affiliated with Docker, Inc.
 
 ERROR_CODE=''
-DOCKERC_PARSE_ARGUMENTS='true'
 
-# Parse options arguments
-while [ "$DOCKERC_PARSE_ARGUMENTS" = 'true' ] && [ "$#" -gt 0 ]; do
+# Parse arguments
+# Dummy while loop to allow breaking
+while true; do
 
-	case "$1" in
+	# Parse options arguments
+	while [ "$#" -gt 0 ]; do
 
-		'--help' | '-h' )
-			DOCKERC_PRINT_HELP='true'
-			shift
-			;;
+		case "$1" in
 
-		'--install-dir' | '-i' )
-			shift
-			# Get installation directory argument
-			if [ -z "$1" ]; then
-				echo 'Error: Missing installation directory.' >&2
+			'--help' | '-h' )
+				# Print help
 				DOCKERC_PRINT_HELP='true'
-				ERROR_CODE=1
-				# Stop parsing arguments
-				DOCKERC_PARSE_ARGUMENTS='false'
+				shift
+				;;
+
+			'--install-dir' | '-i' )
+				shift
+				# Check for installation directory argument
+				if [ -z "$1" ]; then
+					echo 'Error: Missing installation directory.' >&2
+					DOCKERC_PRINT_HELP='true'
+					ERROR_CODE=1
+					break
+				fi
+				# Set installation directory
+				DOCKERC_INSTALL_DIR="$1"
+				shift
+				;;
+
+			* )
 				break
-			fi
-			DOCKERC_INSTALL_DIR="$1"
-			shift
-			;;
+				;;
 
-		* )
-			# Unknown option, maybe first argument
-			# Stop parsing options
-			break
-			;;
+		esac
 
-	esac
+	done
 
-done
-
-if [ "$DOCKERC_PARSE_ARGUMENTS" = 'true' ]; then
-	# Parse positional arguments
+	if [ "$DOCKERC_PRINT_HELP" = 'true' ]; then
+		# Stop parsing arguments
+		break
+	fi
 
-	# Parse install tag optional argument
-	if [ "$#" -gt 0 ]; then
-		DOCKERC_INSTALL_TAG="$1"
-		shift
+	# Check for optional positional arguments
+	if [ "$#" -le 0 ]; then
+		# No more arguments
+		break
 	fi
 
-fi
+	# Parse first optional positional argument
+	# Parse install tag argument
+	DOCKERC_INSTALL_TAG="$1"
+	shift
+
+	# Stop parsing arguments
+	break
+
+done
 
 if [ "$DOCKERC_PRINT_HELP" = 'true' ]; then
 	# Print help & exit
-	echo "Usage: $0 [options] [tag]"
+	echo "Usage: $0 --update [options] [tag]"
 	echo ''
 	echo 'Options:'
-	echo '  --help, -h         Display this help message'
-	echo '  --install-dir, -i  Installation directory (defaults to /usr/local/bin)'
+	echo '  -h, --help         Print this help message'
+	echo '  -i, --install-dir  Set installation directory'
+	echo "    (defaults to directory '/usr/local/bin')"
 	echo ''
 	echo 'Arguments:'
-	echo '  tag  DockerC tag/version to install (defaults to HEAD)'
+	echo '  tag  DockerC tag/version to install'
+	echo '    (defaults to latest version)'
 	exit ${ERROR_CODE:-0}
 fi
 
-# Get installation directory
+# Get install directory
 INSTALL_DIR='/usr/local/bin' # Default installation directory
 if [ -n "$DOCKERC_INSTALL_DIR" ]; then
 	# Use from argument or environment variable
 	INSTALL_DIR="$DOCKERC_INSTALL_DIR"
 fi
 
 # Get install tag
-INSTALL_TAG='HEAD' # Default required tag
+INSTALL_TAG='latest'
 if [ -n "$DOCKERC_INSTALL_TAG" ]; then
 	# Use from argument or environment variable
-	INSTALL_TAG="$DOCKERC_INSTALL_TAG"
+	if
+		[ "$DOCKERC_INSTALL_TAG" = 'HEAD' ] || [ "$DOCKERC_INSTALL_TAG" = 'head' ] ||
+		[ "$DOCKERC_INSTALL_TAG" = '.' ] || [ "$DOCKERC_INSTALL_TAG" = '-' ]
+	then
+		INSTALL_TAG='HEAD'
+	else
+		INSTALL_TAG="$DOCKERC_INSTALL_TAG"
+	fi
+fi
+
+if [ ! -d "$INSTALL_DIR" ]; then
+	echo "Error: Install directory '$INSTALL_DIR' does not exist." >&2
+	exit 1
+fi
+
+get_latest_version() {
+	# Syntax: '"tag_name": "v1.0.0",'
+	LATEST_VERSION_JSON=$(
+		curl -fsSL "https://api.github.com/repos/matiboux/dockerc/releases/latest" 2>/dev/null \
+		| grep -Eo '"tag_name": "(.+?)",'
+	)
+
+	if [ -n "$LATEST_VERSION_JSON" ]; then
+		# Extract version from matched string
+		# Remove `"tag_name": "` (13 characters) and `",` (2 characters)
+		if [ "$(uname -s)" = 'Darwin' ]; then
+			# MacOS
+			LATEST_VERSION="${LATEST_VERSION_JSON:13:$((${#LATEST_VERSION_JSON}-13-2))}"
+		else
+			# Linux
+			LATEST_VERSION=$(expr substr "$LATEST_VERSION_JSON" $(expr 1 + 13) $(expr length "$LATEST_VERSION_JSON" - 13 - 2))
+		fi
+
+		echo "$LATEST_VERSION"
+	fi
+}
+
+if [ "$INSTALL_TAG" = 'latest' ]; then
+	# Default install tag is latest released version
+	INSTALL_TAG="$(get_latest_version)"
+	if [ -z "$INSTALL_TAG" ]; then
+		echo 'Error: Failed to get DockerC latest version.' >&2
+		exit 1
+	fi
 fi
 
 # Check that docker is installed
@@ -97,15 +153,17 @@ if [ $? -ne 0 ]; then
 	exit 1
 fi
 
-curl -fsSL "https://raw.githubusercontent.com/matiboux/dockerc/$INSTALL_TAG/dockerc" -o "$INSTALL_DIR/dockerc"
-if [ $? -ne 0 ]; then
-	echo 'Error: DockerC installation failed.' >&2
+curl -fsSL "https://raw.githubusercontent.com/matiboux/dockerc/$INSTALL_TAG/dockerc" 2>/dev/null \
+	-o "$INSTALL_DIR/dockerc"
+CURL_CODE=$?
+if [ "$CURL_CODE" -ne 0 ]; then
+	echo "Error: Failed to download DockerC ($INSTALL_TAG) in '$INSTALL_DIR' (curl error $CURL_CODE)." >&2
 	exit 1
 fi
 
 chmod +x "$INSTALL_DIR/dockerc"
 if [ $? -ne 0 ]; then
-	echo 'Error: Failed to add execute permission.' >&2
+	echo 'Error: Failed to add execute permission to DockerC.' >&2
 	exit 1
 fi