Cache disk list to avoid multiple lsblk calls

Add get_disk_list() function that caches the output of lsblk
on first call. Subsequent calls return the cached value,
reducing overhead when multiple functions need to iterate
over disk devices.

#8

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

proxDoc.sh

@@ -13,6 +13,12 @@ readonly CMD_TIMEOUT=30  # Default timeout in seconds for external commands
 # Optional log file - set via environment variable PROXDOC_LOGFILE
 LOGFILE="${PROXDOC_LOGFILE:-}"
 
+###################
+# Cached Data
+###################
+# Disk list cache - populated on first use
+DISK_LIST=""
+
 ###################
 # Pattern Constants
 ###################
@@ -114,6 +120,14 @@ checkIfOnHypervisor() {
     command -v pveversion >/dev/null 2>&1
 }
 
+# Get disk list with caching to avoid multiple lsblk calls
+get_disk_list() {
+    if [[ -z "$DISK_LIST" ]]; then
+        DISK_LIST=$(lsblk -d -o name 2>/dev/null | grep -E "$DISK_DEVICE_PATTERN")
+    fi
+    echo "$DISK_LIST"
+}
+
 ###################
 # System Information Functions
 ###################
@@ -155,7 +169,7 @@ get_disk_health() {
             if ! timeout $CMD_TIMEOUT smartctl -H "/dev/$disk"; then
                 log_message warn "smartctl timed out or failed for /dev/$disk"
             fi
-        done < <(lsblk -d -o name | grep -E "$DISK_DEVICE_PATTERN")
+        done <<< "$(get_disk_list)"
     else
         log_message warn "smartctl not found. Install smartmontools for disk health monitoring"
     fi
@@ -588,7 +602,7 @@ quick_health_check() {
             else
                 echo -e "/dev/$disk: ${YELLOW}check timed out or unavailable${NC}"
             fi
-        done < <(lsblk -d -o name | grep -E "$DISK_DEVICE_PATTERN")
+        done <<< "$(get_disk_list)"
     fi
 
     # Node Exporter