'switch' command now defaults to previous session if present

src/command/session.rs

@@ -8,21 +8,18 @@ use tmux_interface::{
 use crate::{
 	error,
 	state::State,
-	util::{ self, NULL }
+	util::{
+		self,
+		message,
+		MSG_PREVIOUS, MSG_SESSION_PATH, NULL
+	}
 };
 
 pub fn path(state: &mut State) {
 	state.session_enforce("path");
 
-	let message = commands::DisplayMessage::new().print().message("#{session_path}");
-
-	let result = Tmux::new().add_command(message).output().unwrap();
-	let text = String::from_utf8(result.0.stdout);
-
-	if let Ok(output) = text {
-		//	trim the trailing line break
-		let target = output.len() - 1;
-		println!("{}", &output[0..target]);
+	if let Some(message) = message(MSG_SESSION_PATH) {
+		println!("{message}");
 	}
 }
 
@@ -36,8 +33,13 @@ pub fn switch(state: &mut State) {
 	//TODO: -d flag handling needs to be done manually
 
 	let args = state.args.clone().finish();
-	if args.len() < 1 { error::missing_target(); }
-	let target = args.get(0).unwrap().to_string_lossy().to_string();
+	let target: String = match args.get(0).map(|s| s.to_str().unwrap()) {
+		None		|
+		Some("-")	=>	if let Some(prev) = message(MSG_PREVIOUS) { prev }
+						else { error::missing_target(); panic!() },
+
+		Some(inner)	=>	inner.to_owned()
+	};
 
 	let exists = util::session_exists(target.clone());
 	if !exists { error::no_target(target.clone()); }

src/state.rs

@@ -9,7 +9,7 @@ use crate::{
 	env::{ env_var, REPO_FILE, TMUX },
 	error,
 	flag::Flags,
-	util::{ find, session_name }
+	util::{ find, message, MSG_SESSION_NAME }
 };
 
 pub struct State<'a> {
@@ -29,7 +29,7 @@ impl State<'_> {
 		let flags = Flags::from(args);
 		let tmux_var = env::var(TMUX).ok();
 		let session = tmux_var.is_some();
-		let title = if session { session_name() } else { None };
+		let title = if session { message(MSG_SESSION_NAME) } else { None };
 		let repository = Repository::find();
 
 		State {

src/util.rs

@@ -14,8 +14,13 @@ use crate::error;
 
 pub const NULL: Option<StdIO> = Some(StdIO::Null);
 
-pub fn session_name() -> Option<String> {
-	let message = commands::DisplayMessage::new().print().message("#{session_name}");
+pub const MSG_PREVIOUS:		&str	= "#{client_last_session}";
+pub const MSG_SESSION_NAME:	&str	= "#S";
+pub const MSG_SESSION_PATH:	&str	= "#{session_path}";
+pub const MSG_WINDOW_NAME:	&str	= "#{window_name}";
+
+pub fn message(fstr: &str) -> Option<String> {
+	let message = commands::DisplayMessage::new().print().message(fstr);
 
 	let result = Tmux::new().add_command(message).output();
 	if let Ok(output) = result {