Fix critical issues in install.sh script - syntax errors, shellcheck warnings, and add version detection fallback

install.sh

@@ -2,20 +2,13 @@
 
 # Copyright Tim Voronov 2020
 version=$(curl -sI https://github.com/go-waitfor/cli/releases/latest | grep Location | awk -F"/" '{ printf "%s", $NF }' | tr -d '\r')
-if [ ! $version ]; then
-    echo "Failed while attempting to install waitfor. Please manually install:"
-    echo ""
-    echo "1. Open your web browser and go to https://github.com/go-waitfor/cli/releases"
-    echo "2. Download the latest release for your platform."
-    echo "3. chmod +x ./waitfor"
-    echo "4. mv ./waitfor /usr/local/bin"
-    exit 1
+if [ ! "$version" ]; then
+    echo "Unable to detect latest version, falling back to 'latest'"
+    version="latest"
 fi
 
 hasCli() {
-    has=$(which waitfor)
-
-    if [ "$?" = "0" ]; then
+    if which waitfor >/dev/null 2>&1; then
         echo
         echo "You already have waitfor!"
         export n=3
@@ -24,16 +17,12 @@ hasCli() {
         sleep $n
     fi
 
-    hasCurl=$(which curl)
-
-    if [ "$?" = "1" ]; then
+    if ! which curl >/dev/null 2>&1; then
         echo "You need curl to use this script."
         exit 1
     fi
 
-    hasTar=$(which tar)
-
-    if [ "$?" = "1" ]; then
+    if ! which tar >/dev/null 2>&1; then
         echo "You need tar to use this script."
         exit 1
     fi
@@ -42,15 +31,12 @@ hasCli() {
 checkHash(){
     sha_cmd="sha256sum"
 
-    if [ ! -x "$(command -v $sha_cmd)" ]; then
+    if [ ! -x "$(command -v "$sha_cmd")" ]; then
         sha_cmd="shasum -a 256"
     fi
 
-    if [ -x "$(command -v $sha_cmd)" ]; then
-
-    (cd $targetDir && curl -sSL $baseUrl/waitfor_checksums.txt | $sha_cmd -c >/dev/null)
-        if [ "$?" != "0" ]; then
-            # rm $targetFile
+    if [ -x "$(command -v "$sha_cmd")" ]; then
+        if ! (cd "$targetDir" && curl -sSL "$baseUrl"/checksums.txt | "$sha_cmd" -c >/dev/null); then
             echo "Binary checksum didn't match. Exiting"
             exit 1
         fi
@@ -64,30 +50,31 @@ getPackage() {
     platform=""
     case $uname in
     "Darwin")
-    platform="_darwin"
-    ;;
+        platform="_darwin"
+        ;;
     "Linux")
-    platform="_linux"
-    ;;
+        platform="_linux"
+        ;;
+    *)
+        echo "Platform $uname is not supported. Exiting"
+        exit 1
+        ;;
     esac
 
-    uname=$(uname -m)
+    uname_arch=$(uname -m)
     arch=""
-    case $uname in
+    case $uname_arch in
     "x86_64")
-    arch="_x86_64"
-    ;;
-    esac
-    case $uname in
-    "aarch64")
-    arch="_arm64"
-    ;;
-    esac
-
-    if [ "$arch" == "" ]; then
-        echo "${$arch} is not supported. Exiting"
+        arch="_amd64"
+        ;;
+    "aarch64"|"arm64")
+        arch="_arm64"
+        ;;
+    *)
+        echo "Architecture $uname_arch is not supported. Exiting"
         exit 1
-    fi
+        ;;
+    esac
 
     suffix=$platform$arch
     targetDir="/tmp/waitfor$suffix"
@@ -96,56 +83,58 @@ getPackage() {
         targetDir="$(pwd)/waitfor$suffix"
     fi
 
-    if [ ! -d $targetDir ]; then
-        mkdir $targetDir
+    if [ ! -d "$targetDir" ]; then
+        mkdir "$targetDir"
     fi
 
     targetFile="$targetDir/waitfor"
 
-    if [ -e $targetFile ]; then
-        rm $targetFile
+    if [ -e "$targetFile" ]; then
+        rm "$targetFile"
     fi
 
-    baseUrl=https://github.com/go-waitfor/cli/releases/download/$version
+    if [ "$version" = "latest" ]; then
+        baseUrl=https://github.com/go-waitfor/cli/releases/latest/download
+    else
+        baseUrl=https://github.com/go-waitfor/cli/releases/download/$version
+    fi
     url=$baseUrl/waitfor$suffix.tar.gz
     echo "Downloading package $url as $targetFile"
 
-    curl -sSL $url | tar xz -C $targetDir
-
-    if [ "$?" = "0" ]; then
+    if ! curl -sSL "$url" | tar xz -C "$targetDir"; then
+        echo "Failed to download or extract package"
+        exit 1
+    fi
 
-    # checkHash
+    checkHash
 
-    chmod +x $targetFile
+    chmod +x "$targetFile"
 
     echo "Download complete."
 
-        if [ "$userid" != "0" ]; then
-            echo
-            echo "========================================================="
-            echo "==    As the script was run as a non-root user the     =="
-            echo "==    following commands may need to be run manually   =="
-            echo "========================================================="
-            echo
-            echo "  sudo cp $targetFile /usr/local/bin/waitfor"
-            echo "  rm -rf $targetDir"
-            echo
-        else
-            echo
-            echo "Running as root - Attempting to move $targetFile to /usr/local/bin"
-
-            mv $targetFile /usr/local/bin/waitfor
-
-            if [ "$?" = "0" ]; then
-                echo "New version of waitfor installed to /usr/local/bin"
-            fi
-
-            if [ -d $targetDir ]; then
-                rm -rf $targetDir
-            fi
-
-            waitfor version
+    if [ "$userid" != "0" ]; then
+        echo
+        echo "========================================================="
+        echo "==    As the script was run as a non-root user the     =="
+        echo "==    following commands may need to be run manually   =="
+        echo "========================================================="
+        echo
+        echo "  sudo cp \"$targetFile\" /usr/local/bin/waitfor"
+        echo "  rm -rf \"$targetDir\""
+        echo
+    else
+        echo
+        echo "Running as root - Attempting to move \"$targetFile\" to /usr/local/bin"
+
+        if mv "$targetFile" /usr/local/bin/waitfor; then
+            echo "New version of waitfor installed to /usr/local/bin"
         fi
+
+        if [ -d "$targetDir" ]; then
+            rm -rf "$targetDir"
+        fi
+
+        waitfor version
     fi
 }