ui: print and set environment variables

ui/src/execute.rs

@@ -135,6 +135,26 @@ named!(
     )
 );
 
+named!(
+    setenv<Action>,
+    do_parse!(
+        ws!(tag!("setenv"))
+            >> key: map_res!(take_until1!("="), std::str::from_utf8)
+            >> ws!(tag!("="))
+            >> val: map_res!(call!(not_line_ending), std::str::from_utf8)
+            >> (SetEnv(key.to_string(), val.to_string()))
+    )
+);
+
+named!(
+    printenv<Action>,
+    do_parse!(
+        ws!(tag!("env"))
+            >> key: map_res!(call!(not_line_ending), std::str::from_utf8)
+            >> (PrintEnv(key.to_string()))
+    )
+);
+
 named!(pub parse_command<Action>,
-    alt_complete!( goto | listing_action | sort | subsort | close | mailinglist)
+    alt_complete!( goto | listing_action | sort | subsort | close | mailinglist | setenv | printenv)
         );

ui/src/execute/actions.rs

@@ -68,4 +68,6 @@ pub enum Action {
     Tab(TabAction),
     ToggleThreadSnooze,
     MailingListAction(MailingListAction),
+    SetEnv(String, String),
+    PrintEnv(String),
 }

ui/src/state.rs

@@ -33,6 +33,7 @@ use melib::backends::{FolderHash, NotifyFn};
 
 use chan::{Receiver, Sender};
 use fnv::FnvHashMap;
+use std::env;
 use std::io::Write;
 use std::result;
 use std::thread;
@@ -471,7 +472,21 @@ impl State {
         let result = parse_command(&cmd.as_bytes()).to_full_result();
 
         if let Ok(v) = result {
-            self.rcv_event(UIEvent::Action(v));
+            match v {
+                SetEnv(key, val) => {
+                    env::set_var(key.as_str(), val.as_str());
+                }
+                PrintEnv(key) => {
+                    self.context.replies.push_back(UIEvent::StatusEvent(
+                        StatusEvent::DisplayMessage(
+                            env::var(key.as_str()).unwrap_or_else(|e| e.to_string()),
+                        ),
+                    ));
+                }
+                v => {
+                    self.rcv_event(UIEvent::Action(v));
+                }
+            }
         }
     }