update comment

shadowsocks-libev-debian.sh

@@ -31,6 +31,52 @@ if [[ $EUID -ne 0 ]]; then
 fi
 }
 
+#Check system
+check_sys(){
+    local checkType=$1
+    local value=$2
+
+    local release=''
+    local systemPackage=''
+
+    if [[ -f /etc/redhat-release ]]; then
+        release="centos"
+        systemPackage="yum"
+    elif cat /etc/issue | grep -q -E -i "debian"; then
+        release="debian"
+        systemPackage="apt"
+    elif cat /etc/issue | grep -q -E -i "ubuntu"; then
+        release="ubuntu"
+        systemPackage="apt"
+    elif cat /etc/issue | grep -q -E -i "centos|red hat|redhat"; then
+        release="centos"
+        systemPackage="yum"
+    elif cat /proc/version | grep -q -E -i "debian"; then
+        release="debian"
+        systemPackage="apt"
+    elif cat /proc/version | grep -q -E -i "ubuntu"; then
+        release="ubuntu"
+        systemPackage="apt"
+    elif cat /proc/version | grep -q -E -i "centos|red hat|redhat"; then
+        release="centos"
+        systemPackage="yum"
+    fi
+
+    if [[ ${checkType} == "sysRelease" ]]; then
+        if [ "$value" == "$release" ]; then
+            return 0
+        else
+            return 1
+        fi
+    elif [[ ${checkType} == "packageManager" ]]; then
+        if [ "$value" == "$systemPackage" ]; then
+            return 0
+        else
+            return 1
+        fi
+    fi
+}
+
 # Disable selinux
 disable_selinux(){
 if [ -s /etc/selinux/config ] && grep 'SELINUX=enforcing' /etc/selinux/config; then
@@ -48,6 +94,8 @@ get_ip(){
 
 # Pre-installation settings
 pre_install(){
+    # Check OS system
+    if check_sys packageManager apt; then
         #Set shadowsocks-libev config password
         echo "Please input password for shadowsocks-libev:"
         read -p "(Default password: teddysun.com):" shadowsockspwd
@@ -63,12 +111,12 @@ pre_install(){
         echo -e "Please input port for shadowsocks-libev [1-65535]:"
         read -p "(Default port: 8989):" shadowsocksport
         [ -z "$shadowsocksport" ] && shadowsocksport="8989"
-    expr $shadowsocksport + 0 &>/dev/null
+        expr ${shadowsocksport} + 0 &>/dev/null
         if [ $? -eq 0 ]; then
-        if [ $shadowsocksport -ge 1 ] && [ $shadowsocksport -le 65535 ]; then
+            if [ ${shadowsocksport} -ge 1 ] && [ ${shadowsocksport} -le 65535 ]; then
                 echo
                 echo "---------------------------"
-            echo "port = $shadowsocksport"
+                echo "port = ${shadowsocksport}"
                 echo "---------------------------"
                 echo
                 break
@@ -99,6 +147,10 @@ pre_install(){
         echo "Getting Public IP address, Please wait a moment..."
         echo -e "Your main public IP is\t\033[32m $(get_ip) \033[0m"
         echo
+    else
+        echo "Error: Your OS is not supported to run it! Please change OS to Debian/Ubuntu and try again."
+        exit 1
+    fi
 }
 
 # Download latest shadowsocks-libev