diff --git a/command/ip.md b/command/ip.md
index d2a3bb87d0..7ad80e10ba 100644
--- a/command/ip.md
+++ b/command/ip.md
@@ -130,7 +130,7 @@ default via 112.124.15.247 dev eth1
 **获取主机所有网络接口**
 
 ```shell
-ip link | grep ^[0-9] | awk -F: '{print $2}'
+ip link | grep -E '^[0-9]' | awk -F: '{print $2}'
 ```
 
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