expose sequence length of trip to onboard unit

1 files changed, 13 insertions, 7 deletions

diff --git a/tools/obu-config b/tools/obu-config
index 0cce2ee..d635834 100755
--- a/tools/obu-config
+++ b/tools/obu-config
@@ -16,14 +16,16 @@ give just the key to look something up
 
 Options:
  -s --statefile: state file
+ -d --delete: explicitly delete an entry
  -h --help: display this help
-" progname))
+" progname progname))
   (exit 0))
 
 (define (main args)
   (let-args
    (cdr args)
    ((statefile "s|state=s")
+    (delete "d|delete")
     (help "h|help" => (cut show-help (car args)))
    . restargs)
 
@@ -32,28 +34,32 @@ Options:
         "./obu-state.edn"
         statefile))
 
-  (if (= (length restargs) 2)
+  (if (or delete (= (length restargs) 2))
       (set file
            (list-ref restargs 0)
-           (list-ref restargs 1))
+           (if delete #f (list-ref restargs 1))
+           delete)
       (display
        (get file
             (list-ref restargs 0))))
   (exit 0)))
 
-(define (set file key value)
+(define (set file key value delete)
   (define data
     (if (file-exists? file)
         (call-with-input-file file parse-edn)
         (edn-map)))
   (define data2
-    (hashmap-set data (string->symbol key) value))
+    (if delete
+        (hashmap-delete data (string->symbol key))
+        (hashmap-set data (string->symbol key) value)))
   (call-with-output-file file
     (cut construct-edn data2 <>)))
 
 (define (get file key)
   (if (file-exists? file)
-      (hashmap-ref
+      (guard (e [else #f])
+        (hashmap-ref
        (call-with-input-file file parse-edn)
-       (string->symbol key))
+       (string->symbol key)))
       #f))