move 'qrencode' from readme dependency to cli usage note

README.md

@@ -92,7 +92,7 @@ sudo lnxrouter -i eth1 -o isp5  --no-dns  --dhcp-dns 1.1.1.1  -6 --dhcp-dns6 [26
 > In this case of usage, it's recommended to:
 > 
 > 1. Stop serving local DNS
-> 2. Tell clients which DNS to use (ISP5's DNS. Or, a safe public DNS, like above example)
+> 2. Tell clients which DNS to use ISP5's DNS. (Or, a safe public DNS, like above example)
 
 > Also, read *Notice 1*
 
@@ -317,6 +317,7 @@ Options:
     -d                      DNS server will take into account /etc/hosts
     -e <hosts_file>         DNS server will take into account additional 
                             hosts file
+    --dns-nocache           DNS server no cache
     
     --mac <MAC>             Set MAC address
     --random-mac            Use random MAC address
@@ -330,7 +331,7 @@ Options:
                             Create WiFi access point
     -p, --password <password>   
                             WiFi password
-    --qr                    Show WiFi QR code in terminal
+    --qr                    Show WiFi QR code in terminal (need qrencode)
     
     --hidden                Hide access point (not broadcast SSID)
     --no-virt               Do not create virtual interface
@@ -397,6 +398,16 @@ On exit of a linux-router instance, script **will do cleanup**, i.e. undo most c
 5. The wifi device which is used to create hotspot is `rfkill unblock`ed
 6. WiFi country code, if user assigns
 
+## Install
+
+1-file-script. Download and run (meet the dependencies).
+
+I'm currently not packaging for any distro. If you do, open a PR and add the link (can be with a version badge) to list here:
+
+| Linux distro |                                                                                                            |
+| ------------ | ---------------------------------------------------------------------------------------------------------- |
+| Any          | download [1-file-script](https://raw.githubusercontent.com/garywill/linux-router/master/lnxrouter) and run |
+
 ## Dependencies
 
 - bash
@@ -409,7 +420,6 @@ On exit of a linux-router instance, script **will do cleanup**, i.e. undo most c
   - iw
   - iwconfig (you only need this if 'iw' can not recognize your adapter)
   - haveged (optional)
-  - qrencode (optional)
 
 ## TODO
 

lnxrouter

@@ -67,6 +67,7 @@ Options:
     -d                      DNS server will take into account /etc/hosts
     -e <hosts_file>         DNS server will take into account additional 
                             hosts file
+    --dns-nocache           DNS server no cache
     
     --mac <MAC>             Set MAC address
     --random-mac            Use random MAC address
@@ -80,7 +81,7 @@ Options:
                             Create WiFi access point
     -p, --password <password>   
                             WiFi password
-    --qr                    Show WiFi QR code in terminal
+    --qr                    Show WiFi QR code in terminal (need qrencode)
     
     --hidden                Hide access point (not broadcast SSID)
     --no-virt               Do not create virtual interface
@@ -156,6 +157,7 @@ define_global_variables(){
     SHOW_DNS_QUERY=0  # log dns
     ETC_HOSTS=0
     ADDN_HOSTS=
+    DNS_NOCACHE=
     CONN_IFACE=    # which interface user choose to use to create network
     INTERNET_IFACE= # which interface to get Internet from
     THISHOSTNAME=   # this host's name the DNS tells clients 
@@ -322,6 +324,10 @@ parse_user_options(){
                 ADDN_HOSTS="$1"
                 shift
                 ;;
+            --dns-nocache)
+                shift
+                DNS_NOCACHE=1
+                ;;
             
             --isolate-clients)
                 shift
@@ -1822,6 +1828,10 @@ write_dnsmasq_conf() {
 			no-poll
 		EOF
     fi
+    if [[ $DNS_NOCACHE -eq 1 ]]; then
+        echo "cache-size=0" >> "$CONFDIR/dnsmasq.conf"
+        echo "no-negcache" >> "$CONFDIR/dnsmasq.conf"
+    fi
     if [[ $IPV6 -eq 1 ]];then
         cat <<- EOF  >> "$CONFDIR/dnsmasq.conf"
 			listen-address=${GATEWAY6}