overwrite file only if download succeeded

acme-downloader.sh

@@ -184,9 +184,10 @@ check_version
 VERSION_STATUS=$?
 
 if [[ -n $FORCE_UPDATE ]]; then
-    curl $SCRIPT_URL -o $0
+    curl $SCRIPT_URL -o ${0}.new
     UPDATE_STATUS=$?
     if [ $UPDATE_STATUS == 0 ]; then
+        rm -f $0; mv ${0}.new $0; chmod 0755 $0
         echo -e "\n$0 updated successfully\n"
     else
         echo -e "\nfailed to update $0"
@@ -198,7 +199,7 @@ fi
 if [[ -n $UPDATE ]]; then
     UPDATE_STATUS="skip"
     if [ $VERSION_STATUS -eq 1 ]; then
-        curl $SCRIPT_URL -o $0
+        curl $SCRIPT_URL -o ${0}.new
         UPDATE_STATUS=$?
     fi
     if [ $UPDATE_STATUS == "skip" ]; then
@@ -206,6 +207,7 @@ if [[ -n $UPDATE ]]; then
         echo -e "\n$0 is already up to date\n"
     elif [ $UPDATE_STATUS -eq 0 ]; then
         EXIT_STATUS=0
+        rm -f $0; mv ${0}.new $0; chmod 0755 $0
         echo -e "\n$0 updated successfully\n"
     else
         EXIT_STATUS=$UPDATE_STATUS
@@ -215,7 +217,6 @@ if [[ -n $UPDATE ]]; then
     clean_up $EXIT_STATUS
 fi
 
-
 if [[ -z $REDIS_TOKEN ]] || [[ -z $VAULT_TOKEN ]] || [[ -z $CERT_NAME ]] || [[ -z $TEAM_NAME ]] || [[ -z $TYPE ]]; then
     echo -e "\n--redis-token, --vault-token, --cert-name, --team-name and --type are mandatory\n"
     usage