Add version command line argument

internal/config_specification.toml

@@ -108,6 +108,10 @@ doc = "Exit after the initial sync is over (don't start Electrum server)."
 name = "cache_merkle_proofs"
 doc = "Cache merkle proofs on subscription (if disabled, they are computed on demand)."
 
+[[switch]]
+name = "version"
+doc = "Print out the program version."
+
 [[param]]
 name = "index_lookup_limit"
 type = "usize"

src/config.rs

@@ -308,6 +308,11 @@ impl Config {
             std::process::exit(1);
         }
 
+        if config.version {
+            println!("v{}", ELECTRS_VERSION);
+            std::process::exit(0);
+        }
+
         let config = Config {
             network: config.network,
             db_path: config.db_dir,