diff --git a/codes/demos/bash/README.md b/codes/demos/bash/README.md
deleted file mode 100644
index b2bea54..0000000
--- a/codes/demos/bash/README.md
+++ /dev/null
@@ -1,4 +0,0 @@
-# OS `codes/bash`
-
-> 本目录的代码是和 `docs/shell.md` 相关的示例代码。
-> 
diff --git a/codes/build/helper.sh b/codes/linux/build/helper.sh
similarity index 100%
rename from codes/build/helper.sh
rename to codes/linux/build/helper.sh
diff --git a/codes/build/java-app-boot.sh b/codes/linux/build/java-app-boot.sh
similarity index 100%
rename from codes/build/java-app-boot.sh
rename to codes/linux/build/java-app-boot.sh
diff --git a/codes/build/java-app-release.sh b/codes/linux/build/java-app-release.sh
similarity index 100%
rename from codes/build/java-app-release.sh
rename to codes/linux/build/java-app-release.sh
diff --git a/codes/build/java-app-run.sh b/codes/linux/build/java-app-run.sh
similarity index 100%
rename from codes/build/java-app-run.sh
rename to codes/linux/build/java-app-run.sh
diff --git a/codes/build/js-app-release.sh b/codes/linux/build/js-app-release.sh
similarity index 100%
rename from codes/build/js-app-release.sh
rename to codes/linux/build/js-app-release.sh
diff --git a/codes/build/main.sh b/codes/linux/build/main.sh
similarity index 100%
rename from codes/build/main.sh
rename to codes/linux/build/main.sh
diff --git a/codes/build/update-code.sh b/codes/linux/build/update-code.sh
similarity index 100%
rename from codes/build/update-code.sh
rename to codes/linux/build/update-code.sh
diff --git a/codes/linux/shell-demos/README.md b/codes/linux/shell-demos/README.md
new file mode 100644
index 0000000..53b8d7d
--- /dev/null
+++ b/codes/linux/shell-demos/README.md
@@ -0,0 +1,3 @@
+# Shell 示例源码
+
+> 本目录的代码是和 `https://github.com/dunwu/os-tutorial/blob/master/docs/linux/scripts/shell.md` 相关的示例代码。
diff --git a/codes/demos/bash/array/arrayDemo.sh b/codes/linux/shell-demos/array/arrayDemo.sh
similarity index 100%
rename from codes/demos/bash/array/arrayDemo.sh
rename to codes/linux/shell-demos/array/arrayDemo.sh
diff --git a/codes/demos/bash/operator/operatorDemo.sh b/codes/linux/shell-demos/operator/operatorDemo.sh
similarity index 100%
rename from codes/demos/bash/operator/operatorDemo.sh
rename to codes/linux/shell-demos/operator/operatorDemo.sh
diff --git a/codes/demos/bash/operator/operatorDemo02.sh b/codes/linux/shell-demos/operator/operatorDemo02.sh
similarity index 100%
rename from codes/demos/bash/operator/operatorDemo02.sh
rename to codes/linux/shell-demos/operator/operatorDemo02.sh
diff --git a/codes/demos/practice/README.md b/codes/linux/shell-demos/practice/README.md
similarity index 100%
rename from codes/demos/practice/README.md
rename to codes/linux/shell-demos/practice/README.md
diff --git a/codes/demos/practice/system/useradd.sh b/codes/linux/shell-demos/practice/system/useradd.sh
similarity index 100%
rename from codes/demos/practice/system/useradd.sh
rename to codes/linux/shell-demos/practice/system/useradd.sh
diff --git a/codes/demos/bash/statement/caseDemo.sh b/codes/linux/shell-demos/statement/caseDemo.sh
similarity index 100%
rename from codes/demos/bash/statement/caseDemo.sh
rename to codes/linux/shell-demos/statement/caseDemo.sh
diff --git a/codes/demos/bash/statement/continueDemo.sh b/codes/linux/shell-demos/statement/continueDemo.sh
similarity index 100%
rename from codes/demos/bash/statement/continueDemo.sh
rename to codes/linux/shell-demos/statement/continueDemo.sh
diff --git a/codes/demos/bash/statement/forDemo.sh b/codes/linux/shell-demos/statement/forDemo.sh
similarity index 100%
rename from codes/demos/bash/statement/forDemo.sh
rename to codes/linux/shell-demos/statement/forDemo.sh
diff --git a/codes/demos/bash/statement/forDemo02.sh b/codes/linux/shell-demos/statement/forDemo02.sh
similarity index 100%
rename from codes/demos/bash/statement/forDemo02.sh
rename to codes/linux/shell-demos/statement/forDemo02.sh
diff --git a/codes/demos/bash/statement/ifDemo.sh b/codes/linux/shell-demos/statement/ifDemo.sh
similarity index 76%
rename from codes/demos/bash/statement/ifDemo.sh
rename to codes/linux/shell-demos/statement/ifDemo.sh
index 5047438..33b417b 100644
--- a/codes/demos/bash/statement/ifDemo.sh
+++ b/codes/linux/shell-demos/statement/ifDemo.sh
@@ -10,8 +10,10 @@ if [[ -z $2 ]]; then
   exit
 fi
 
-if [[ $1 == $2 ]]; then
-  echo "\$1 == \$2";
+if [[ $1 > $2 ]]; then
+  echo "\$1 > \$2";
+elif [[ $1 < $2 ]]; then
+  echo "\$1 < \$2";
 else
   echo "\$1 != \$2";
 fi
diff --git a/codes/demos/bash/statement/selectDemo.sh b/codes/linux/shell-demos/statement/selectDemo.sh
similarity index 100%
rename from codes/demos/bash/statement/selectDemo.sh
rename to codes/linux/shell-demos/statement/selectDemo.sh
diff --git a/codes/demos/bash/statement/whileDemo.sh b/codes/linux/shell-demos/statement/whileDemo.sh
similarity index 100%
rename from codes/demos/bash/statement/whileDemo.sh
rename to codes/linux/shell-demos/statement/whileDemo.sh
diff --git a/codes/demos/bash/variable/positionalVariableDemo.sh b/codes/linux/shell-demos/variable/positionalVariableDemo.sh
similarity index 100%
rename from codes/demos/bash/variable/positionalVariableDemo.sh
rename to codes/linux/shell-demos/variable/positionalVariableDemo.sh
diff --git a/codes/demos/bash/variable/variableDemo.sh b/codes/linux/shell-demos/variable/variableDemo.sh
similarity index 100%
rename from codes/demos/bash/variable/variableDemo.sh
rename to codes/linux/shell-demos/variable/variableDemo.sh