Use case statement instead of many if's

example-dns-01-nsupdate-script.md

@@ -14,30 +14,24 @@ This hook script uses the nsupdate utility from the bind package to solve dns-01
 set -e
 set -u
 set -o pipefail
-umask 077
 
 NSUPDATE="nsupdate -k /path/to/Kdnsupdatekey.private"
-done="no"
 
-if [[ "$1" = "deploy_challenge" ]]; then
+case "$1" in
+    "deploy_challenge")
         printf "update add _acme-challenge.%s. 300 in TXT \"%s\"\n\n" "${2}" "${4}" | $NSUPDATE
-    done="yes"
+        ;;
-fi
+    "clean_challenge")
-
-if [[ "$1" = "clean_challenge" ]]; then
         printf "update delete _acme-challenge.%s. 300 in TXT \"%s\"\n\n" "${2}" "${4}" | $NSUPDATE
-    done="yes"
+        ;;
-fi
+    "deploy_cert")
-
-if [[ "${1}" = "deploy_cert" ]]; then
         # do nothing for now
-    done="yes"
+        ;;
-fi
+    *)
-
-if [[ ! "${done}" = "yes" ]]; then
         echo Unkown hook "${1}"
         exit 1
-fi
+        ;;
+esac
 
 exit 0
 ```