Implement eww get command (#319)

crates/eww/src/app.rs

@@ -53,6 +53,10 @@ pub enum DaemonCommand {
         all: bool,
         sender: DaemonResponseSender,
     },
+    GetVar {
+        name: String,
+        sender: DaemonResponseSender,
+    },
     PrintDebug(DaemonResponseSender),
     PrintWindows(DaemonResponseSender),
 }
@@ -176,6 +180,13 @@ impl App {
                     };
                     sender.send_success(output)?
                 }
+                DaemonCommand::GetVar { name, sender } => {
+                    let vars = self.eww_state.get_variables();
+                    match vars.get(name.as_str()) {
+                        Some(x) => sender.send_success(x.to_string())?,
+                        None => sender.send_failure(format!("Variable not found \"{}\"", name))?,
+                    }
+                }
                 DaemonCommand::PrintWindows(sender) => {
                     let output = self
                         .eww_config

crates/eww/src/main.rs

@@ -13,7 +13,7 @@ extern crate gtk;
 extern crate gtk_layer_shell as gtk_layer_shell;
 
 use anyhow::*;
-use daemon_response::DaemonResponseReceiver;
+use daemon_response::{DaemonResponse, DaemonResponseReceiver};
 use opts::ActionWithServer;
 use std::{
     os::unix::net,
@@ -145,7 +145,13 @@ fn handle_server_command(paths: &EwwPaths, action: &ActionWithServer, connect_at
     log::debug!("Connected to Eww server ({}).", &paths.get_ipc_socket_file().display());
     let response = client::do_server_call(&mut stream, action).context("Error while forwarding command to server")?;
     if let Some(response) = response {
-        println!("{}", response);
+        match response {
+            DaemonResponse::Success(x) => println!("{}", x),
+            DaemonResponse::Failure(x) => {
+                eprintln!("{}", x);
+                bail!("Error, server command failed");
+            }
+        }
     }
     Ok(())
 }

crates/eww/src/opts.rs

@@ -81,11 +81,11 @@ pub enum ActionWithServer {
         mappings: Vec<(VarName, DynVal)>,
     },
 
-    // Open the GTK debugger
+    /// Open the GTK debugger
     #[structopt(name = "inspector", alias = "debugger")]
     OpenInspector,
 
-    /// open a window
+    /// Open a window
     #[structopt(name = "open", alias = "o")]
     OpenWindow {
         /// Name of the window you want to open.
@@ -131,7 +131,7 @@ pub enum ActionWithServer {
     #[structopt(name = "reload", alias = "r")]
     Reload,
 
-    /// kill the eww daemon
+    /// Kill the eww daemon
     #[structopt(name = "kill", alias = "k")]
     KillServer,
 
@@ -147,6 +147,10 @@ pub enum ActionWithServer {
         all: bool,
     },
 
+    /// Get the value of a variable if defined
+    #[structopt(name = "get")]
+    GetVar { name: String },
+
     /// Print the names of all configured windows. Windows with a * in front of them are currently opened.
     #[structopt(name = "windows")]
     ShowWindows,
@@ -219,6 +223,9 @@ impl ActionWithServer {
             ActionWithServer::ShowState { all } => {
                 return with_response_channel(|sender| app::DaemonCommand::PrintState { all, sender })
             }
+            ActionWithServer::GetVar { name } => {
+                return with_response_channel(|sender| app::DaemonCommand::GetVar { name, sender })
+            }
             ActionWithServer::ShowDebug => return with_response_channel(app::DaemonCommand::PrintDebug),
         };
         (command, None)