fix online code-exercise issue, and optimize readme

Author: Sunrisepeak

.devcontainer/devcontainer.json

@@ -13,5 +13,5 @@
   },
   "remoteUser": "vscode",
   "postCreateCommand": "/bin/bash .devcontainer/postCreate.sh",
-  "postAttachCommand": "xlings checker"
+  "postAttachCommand": "d2x checker"
 }

.devcontainer/postCreate.sh

@@ -6,7 +6,13 @@ sudo apt-get update
 sudo apt-get install -y ncurses-bin libtinfo6 libncursesw6 curl ca-certificates git
 
 if ! command -v xlings >/dev/null 2>&1; then
-  curl -fsSL https://d2learn.org/xlings-install.sh | bash
+  curl -fsSL https://raw.githubusercontent.com/d2learn/xlings/refs/heads/main/tools/other/quick_install.sh | bash -s -- v0.4.2
 fi
 
-echo "xlings installed"
+echo "xlings installed"
+
+# source PATH so xlings/d2x are available in this shell
+export PATH="$HOME/.xlings/subos/current/bin:$PATH"
+[ -f "$HOME/.bashrc" ] && source "$HOME/.bashrc"
+
+xlings install

.github/workflows/online-ebook.yml

@@ -40,17 +40,23 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
-      - name: Install mdBook by Xlings
+
+      - name: Install Xlings
+        env:
+          XLINGS_NON_INTERACTIVE: 1
         run: |
           curl -fsSL https://d2learn.org/xlings-install.sh | bash
-          export PATH=/home/xlings/.xlings_data/bin:$PATH
-          xlings install mdbook@${MDBOOK_VERSION} --global -y
+          echo "PATH=$HOME/.xlings/subos/current/bin:$PATH" >> "$GITHUB_ENV"
+
+      - name: Install mdBook
+        run: xlings install mdbook@${MDBOOK_VERSION} -y
+
       - name: Setup Pages
         id: pages
         uses: actions/configure-pages@v4
+
       - name: Build with mdBook
         run: |
-          export PATH=/home/xlings/.xlings_data/bin:$PATH
           ./build.sh
       - name: Upload artifact
         uses: actions/upload-pages-artifact@v3

README.md

@@ -67,6 +67,7 @@ irm https://d2learn.org/xlings-install.ps1.txt | iex
 </details>
 
 ```bash
+xlings install d2x -y
 d2x install d2mcpp
 cd d2mcpp
 d2x checker

README.zh.hant.md

@@ -67,6 +67,7 @@ irm https://d2learn.org/xlings-install.ps1.txt | iex
 </details>
 
 ```bash
+xlings install d2x -y
 d2x install d2mcpp
 cd d2mcpp
 d2x checker

README.zh.md

@@ -67,6 +67,7 @@ irm https://d2learn.org/xlings-install.ps1.txt | iex
 </details>
 
 ```bash
+xlings install d2x -y
 d2x install d2mcpp
 cd d2mcpp
 d2x checker

book/en/src/README.md

@@ -63,6 +63,7 @@ irm https://d2learn.org/xlings-install.ps1.txt | iex
 </details>
 
 ```bash
+xlings install d2x -y
 d2x install d2mcpp
 cd d2mcpp
 d2x checker

book/src/README.md

@@ -63,6 +63,7 @@ irm https://d2learn.org/xlings-install.ps1.txt | iex
 </details>
 
 ```bash
+xlings install d2x -y
 d2x install d2mcpp
 cd d2mcpp
 d2x checker