diff --git a/tools/alpine.sh b/tools/alpine.sh
index 0879e84..89442a4 100755
--- a/tools/alpine.sh
+++ b/tools/alpine.sh
@@ -5,8 +5,7 @@ set -e
 set_mirror()
 {
     MIRROR=${1:-"mirrors.tuna.tsinghua.edu.cn"}
-    MIRROR=${MIRROR//\//\\\/}
-    sed -i "s/dl-cdn.alpinelinux.org/$MIRROR/g" /etc/apk/repositories
+    sed -i "s@dl-cdn.alpinelinux.org@$MIRROR@g" /etc/apk/repositories
 }
 
 apk_add()
diff --git a/tools/ubuntu.sh b/tools/ubuntu.sh
index c9309f9..e6a98cf 100755
--- a/tools/ubuntu.sh
+++ b/tools/ubuntu.sh
@@ -5,7 +5,6 @@ set -e
 set_mirror()
 {
     MIRROR=${1:-"mirrors.tuna.tsinghua.edu.cn"}
-    MIRROR=${MIRROR//\//\\\/}
     sed -i "s@http://.*archive.ubuntu.com@https://${MIRROR}@g" /etc/apt/sources.list
     sed -i "s@http://.*security.ubuntu.com@https://${MIRROR}@g" /etc/apt/sources.list
 }
@@ -16,9 +15,14 @@ apt_install()
     apt-get update
     for i in {man-db,vim,ca-certificates}; do apt-get install $i -y; done
 
-    # mass installation
-    apt-get install git tmux zsh curl wget dialog net-tools dnsutils netcat traceroute sudo python3 python3-pip cron inetutils-ping openssh-client openssh-server htop gcc g++ cmake make zip less bsdmainutils
-    for i in {fzf,ripgrep}; do apt-get install $i -y; done
+    # lite
+    apt-get install -y git zsh bash tmux vim curl inetutils-ping less bsdmainutils
+
+    # full
+    if [[ -z "$DFS_LITE" ]]; then
+        apt-get install wget dialog net-tools dnsutils netcat traceroute sudo python3 python3-pip cron openssh-client openssh-server htop gcc g++ cmake make zip
+        for i in {fzf,ripgrep}; do apt-get install -y $i; done
+    fi
 }
 
 set_timezone()