diff --git a/demo.md b/demo.md
index 3e41abe..09bc0f0 100644
--- a/demo.md
+++ b/demo.md
@@ -14,6 +14,25 @@ if [ "$port" == "" ]; then
 fi
 ```
 
+#### 检测指定服务是否正常运行
+
+新建文件写入以下内容
+
+```
+#!/usr/bin/env bash
+
+read name
+pgrep $name > /dev/null
+if [ $? -gt 0 ];then
+    echo "`date` $name is stop" >> ~/mysql_listen.log
+    systemctl $name mysql
+else
+    echo "`date` $name running" >> ~/mysql_listen.log
+fi
+```
+
+给脚本添加执行权限后运行，输入服务名称即可
+
 设置定时任务
 
 ```
diff --git a/netstat-system.md b/netstat-system.md
index c4c2552..133701e 100644
--- a/netstat-system.md
+++ b/netstat-system.md
@@ -321,3 +321,11 @@ bg 1 #将任务编号为 1 调到后台运行
 fg 1 #将任务编号为 1 调到前台运行
 ```
 
+#### pgrep 命令
+
+```
+pgrep nginx # 查看 nginx 进程
+
+pgrep -l nginx  #查看 nginx 进程名称
+```
+