added nesting flag

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "remux"
-version = "0.1.0"
+version = "0.1.2"
 edition = "2021"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

src/error.rs

@@ -30,8 +30,15 @@ pub fn missing_target() {
 	exit(4);
 }
 
+///	non-terminal environment prevention; code 5
 pub fn not_terminal() {
 	println!("remux: not running from a terminal");
 	exit(5);
 }
 
+///	tried to nest while not in a session; code 6
+pub fn not_nesting() {
+	println!("remux: cannot use nesting flag outside a TMUX session");
+	exit(6);
+}
+

src/main.rs

@@ -1,4 +1,7 @@
-use std::io::{ stdout, IsTerminal };
+use std::{
+	env::{ set_var, var },
+	io::{ stdout, IsTerminal }
+};
 
 use pico_args::Arguments;
 
@@ -10,17 +13,28 @@ mod util;
 use help::help;
 
 fn main() {
+	//	collect args
 	let mut args = Arguments::from_env();
 
+	//	consume flags
 	if args.contains(["-h", "--help"]) {
 		help(&mut args);
 		return;
 	}
+	let nesting = args.contains(["-n", "--nest"]);
+	let tmux_var = var("TMUX").ok();
+	if nesting {
+		if tmux_var.is_none() {
+			error::not_nesting();
+		}
+		set_var("TMUX", "");
+	}
 
 	if !stdout().is_terminal() { error::not_terminal(); }
 
 	let subcommand = args.subcommand().unwrap();
 
+	//	invoke subcommand function
 	match subcommand.as_deref() {
 		Some("h" | "help")
 			=>	help(&mut args),
@@ -44,5 +58,9 @@ fn main() {
 		_
 			=>	error::no_subcommand(subcommand.unwrap())
 	}
+
+	if nesting {
+		set_var("TMUX", tmux_var.unwrap());
+	}
 }
 

src/util.rs

@@ -22,7 +22,7 @@ pub fn get_sessions() -> Option<Vec<Session>> {
 pub fn prevent_nest() {
 	let tmux = var("TMUX").ok();
 	if tmux.is_some() && tmux.unwrap() != "" {
-		println!("Sessions should be nested with care; unset TMUX to allow.");
+		println!("Sessions should be nested with care; unset TMUX or use the '-n' flag to allow.");
 		exit(1);
 	}
 }