system: monitoring: Add a procedure to get the total available ram in the current system in bytes

modules/radix/system/monitoring.scm

@@ -4,6 +4,7 @@
   #:export (current-memory-info
             current-ram-usage
             current-swap-usage
+            ram-total
 
             current-battery-capacity))
 
@@ -29,6 +30,13 @@
            (cut string-split <> #\:))
          lines)))
 
+(define (ram-total)
+  (let* ((port (open "/proc/meminfo" O_RDONLY))
+         (_ (read port))
+         (mem-in-b (* (read port) 1024)))
+    (close-input-port port)
+    mem-in-b))
+
 (define (current-ram-usage)
   (apply - (map (cut assoc-ref (current-memory-info) <>)
                 '("MemTotal" "MemFree" "Buffers" "Cached" "SReclaimable"))))