install.sh: small fixes (#108)

- replace sed fork with bash string manipulation
- variable enclosure by quotation marks
- check for existence of $HOME/.local/bin
- check $PATH for $HOME/.local/bin

The last two are more MacOS specific changes as the OS does not play by XDG Base
Directory Specification and the path var therefore does not contain the folder
by default, nor does it even exist on a fresh install.

scripts/install.sh

@@ -7,7 +7,7 @@ REPO_OWNER="SneaksAndData"
 REPO_NAME="snd-cli-go"
 LATEST_RELEASE_TAG=$(curl --silent "https://api.github.com/repos/$REPO_OWNER/$REPO_NAME/releases/latest" | jq -r .tag_name)
 
-VERSION=$(echo $LATEST_RELEASE_TAG | sed 's/^v//')
+VERSION="${LATEST_RELEASE_TAG#v}"
 BASE_BIN_NAME="snd-cli-go_$VERSION"
 
 echo "Determining target OS and architecture..."
@@ -47,12 +47,22 @@ chmod +x "$base_path/snd-cli-go"
 
 if [ -e "$HOME/.local/bin/snd" ]; then
    echo "Removing symlink..."
-   rm $HOME/.local/bin/snd
+   rm "$HOME/.local/bin/snd"
 fi
 
 # Create a symbolic link to the application
 echo "Creating the symlink..."
+local_bin="$HOME/.local/bin"
+if [ ! -d "$local_bin" ]; then
+    mkdir -p "$local_bin"
+fi
 ln -s "$base_path/snd-cli-go" "$HOME/.local/bin/snd"
 
+# Check if $PATH contains $HOME/.local/bin
+case ":$PATH:" in
+    *:"$local_bin":*) ;; #do nothing
+    *) >&2 echo "WARNING: $local_bin not in \$PATH. Please update your \$PATH variable for the shell you want to use." ;;
+esac
+
 echo "Please restart your terminal for the changes to take effect."
-echo "After restarting, you can try running 'snd --help'. :)"
+echo "After restarting, you can try running 'snd --help'. :)"