Reduce code-duplication

Signed-off-by: DL6ER <dl6er@dl6er.de>

automated install/basic-install.sh

@@ -2030,21 +2030,9 @@ FTLcheckUpdate() {
             # Alt branches don't have a tagged version against them, so just
             # confirm the checksum of the local vs remote to decide whether we
             # download or not
-            remoteSha1=$(curl -sSL --fail "https://ftl.pi-hole.net/${ftlBranch}/${binary}.sha1" | cut -d ' ' -f 1)
-            localSha1=$(sha1sum "${ftlLoc}" | cut -d ' ' -f 1)
-
-            # Check we downloaded a valid checksum (no 404 or other error like
-            # no DNS resolution)
-            if [[ ! "${remoteSha1}" =~ ^[a-f0-9]{40}$ ]]; then
-                printf "  %b Remote checksum not available, trying to download binary from ftl.pi-hole.net.\\n" "${CROSS}"
-                return 0
-            elif [[ "${remoteSha1}" != "${localSha1}" ]]; then
-                printf "  %b Checksums do not match, downloading from ftl.pi-hole.net.\\n" "${INFO}"
-                return 0
-            else
-                printf "  %b Checksum of installed binary matches remote. No need to download!\\n" "${INFO}"
-                return 1
-            fi
+            printf "  %b FTL binary already installed. Confirming Checksum...\\n" "${INFO}"
+            checkSumFile="https://ftl.pi-hole.net/${ftlBranch}/${binary}.sha1"
+            # Continue further down...
         else
             return 0
         fi
@@ -2066,34 +2054,39 @@ FTLcheckUpdate() {
 
             # Check if the installed version matches the latest version
             if [[ "${FTLversion}" != "${FTLlatesttag}" ]]; then
-                # If the installed version does not match the latest version, then download
+                # If the installed version does not match the latest version,
+                # then download
                 return 0
             else
                 # If the installed version matches the latest version, then
                 # check the installed sha1sum of the binary vs the remote
                 # sha1sum. If they do not match, then download
-                printf "  %b Latest FTL Binary already installed (%s). Confirming Checksum...\\n" "${INFO}" "${FTLlatesttag}"
-
-                remoteSha1=$(curl -sSL --fail "https://github.com/pi-hole/FTL/releases/download/${FTLversion%$'\r'}/${binary}.sha1" | cut -d ' ' -f 1)
-                localSha1=$(sha1sum "${ftlLoc}" | cut -d ' ' -f 1)
-
-                # Check we downloaded a valid checksum (no 404 or other error like
-                # no DNS resolution)
-                if [[ ! "${remoteSha1}" =~ ^[a-f0-9]{40}$ ]]; then
-                    printf "  %b Remote checksum not available, trying to redownload binary...\\n" "${CROSS}"
-                    return 0
-                elif [[ "${remoteSha1}" != "${localSha1}" ]]; then
-                    printf "  %b Corruption detected, redownloading binary...\\n" "${CROSS}"
-                    return 0
-                else
-                    printf "  %b Checksum correct. No need to download!\\n" "${INFO}"
-                    return 1
-                fi
+                printf "  %b Latest FTL binary already installed (%s). Confirming Checksum...\\n" "${INFO}" "${FTLlatesttag}"
+                checkSumFile="https://github.com/pi-hole/FTL/releases/download/${FTLversion%$'\r'}/${binary}.sha1"
+                # Continue further down...
             fi
         else
             return 0
         fi
     fi
+
+    # If we reach this point, we need to check the checksum of the local vs
+    # remote to decide whether we download or not
+    remoteSha1=$(curl -sSL --fail "${checkSumFile}" | cut -d ' ' -f 1)
+    localSha1=$(sha1sum "${ftlLoc}" | cut -d ' ' -f 1)
+
+    # Check we downloaded a valid checksum (no 404 or other error like
+    # no DNS resolution)
+    if [[ ! "${remoteSha1}" =~ ^[a-f0-9]{40}$ ]]; then
+        printf "  %b Remote checksum not available, trying to redownload binary...\\n" "${CROSS}"
+        return 0
+    elif [[ "${remoteSha1}" != "${localSha1}" ]]; then
+        printf "  %b Corruption detected, redownloading binary...\\n" "${CROSS}"
+        return 0
+    fi
+
+    printf "  %b Checksum correct. No need to download!\\n" "${INFO}"
+    return 1
 }
 
 # Detect suitable FTL binary platform