Restore to cloudflare if no backup found

shecanman

@@ -6,15 +6,14 @@
 # If you have found any issue or have some feature request:
 # Please raise them here: https://github.com/amirz98/shecanman/issues
 
-VRESION="0.2.0"
+VRESION="0.3.0"
 
 SHEACN_DNS_ARRAY=("178.22.122.100" "185.51.200.2")
 
 SHECAN_DNS="# Shecan dns server
 nameserver 178.22.122.100
 nameserver 185.51.200.2"
 
-
 # check if stdout is a terminal
 if test -t 1; then
   # see if it supports colors
@@ -25,6 +24,7 @@ if test -t 1; then
     normal="$(tput sgr0)"
     red="$(tput setaf 1)"
     green="$(tput setaf 2)"
+    yellow="$(tput setaf 3)"
   fi
 fi
 
@@ -59,6 +59,7 @@ function exit_if_not_root() {
 }
 
 function is_shecan_on() {
+  # read dns config file line by line
   while read -r line; do
     # ignore the line if does not begin with nameserver
     [[ ! $line =~ ^nameserver.* ]] && continue
@@ -81,7 +82,7 @@ function switch_on() {
   else
     exit_if_not_root
     cp /etc/resolv.conf /etc/resolv.conf.backup
-    echo "$SHECAN_DNS" >/etc/resolv.conf
+    echo -e "$SHECAN_DNS" >/etc/resolv.conf
     echo "${bold}${green} Shecan DNS switched on.${normal}"
   fi
 }
@@ -91,9 +92,51 @@ function switch_off() {
     echo "${bold}${green} Shecan is not in use.${normal}"
   else
     exit_if_not_root
-    cp /etc/resolv.conf.backup /etc/resolv.conf
-    rm /etc/resolv.conf.backup
-    echo "${bold}${green} Shecan DNS switched off.${normal}"
+    # restore backup configs if exists
+    if [[ -f /etc/resolv.conf.backup ]]; then
+      cp /etc/resolv.conf.backup /etc/resolv.conf
+      rm /etc/resolv.conf.backup
+      echo "${bold}${green} Shecan DNS switched off.${normal}"
+    else
+      # dns config backup file not found; this happens only when the user changes the dns configs manually
+      # restruct a valid dns config based on current dns config file
+      new_config="# Restored by ShecanMan\n"
+      non_shecan_dns_count=0
+      # read dns config file line by line, keep dns servers that are not for Shecan.ir
+      while read -r line; do
+        # ignore the line if does not begin with nameserver
+        [[ ! $line =~ ^nameserver.* ]] && continue
+
+        is_shecan_dns=1
+        for shecan in "${SHEACN_DNS_ARRAY[@]}"; do
+          if [[ "$line" =~ .*"$shecan".* ]]; then
+            # found a non-shecan dns
+            is_shecan_dns=0
+            break
+          fi
+        done
+
+        # keep the dns if it's not a shecan dns
+        if [[ $is_shecan_dns == 1 ]]; then
+          new_config+="$line\n"
+          non_shecan_dns_count=$((non_shecan_dns_count + 1))
+        fi
+      done </etc/resolv.conf
+
+      # if no non-shecan dns found, use Cloudflare dns server as a single dns entry
+      if [[ $non_shecan_dns_count == 0 ]]; then
+        new_config+="nameserver 1.1.1.1"
+      fi
+
+      # save the configs
+      echo -e $new_config >/etc/resolv.conf
+
+      if [[ $non_shecan_dns_count == 0 ]]; then
+        echo "${bold}${yellow} Backup DNS not found! Notice that your DNS is now set to Cloudflare (1.1.1.1).${normal}"
+      fi
+
+      echo "${bold}${green} Shecan DNS switched off.${normal}"
+    fi
   fi
 }