Can read consumption from a file

central_backend/src/app_config.rs

@@ -6,7 +6,7 @@ use std::path::{Path, PathBuf};
 pub enum ConsumptionBackend {
     /// Constant consumption value
     Constant {
-        #[clap(long, default_value_t = 500)]
+        #[clap(short, long, default_value_t = 500)]
         value: i32,
     },
 
@@ -17,6 +17,12 @@ pub enum ConsumptionBackend {
         #[clap(long, default_value_t = 20000)]
         max: i32,
     },
+
+    /// Read consumption value in a file, on the filesystem
+    File {
+        #[clap(short, long, default_value = "/dev/shm/consumption.txt")]
+        path: String,
+    },
 }
 
 /// Solar system central backend