New tab opens on current directory

This patch add a new feature, now tab behavior now inherits the
active tab’s current directory on Linux controlled by a settings
toggle, and default is off

src/terminal.rs

@@ -28,7 +28,8 @@ use indexmap::IndexSet;
 use std::{
     borrow::Cow,
     collections::HashMap,
-    io, mem,
+    fs, io, mem,
+    path::PathBuf,
     sync::{
         Arc, Mutex, Weak,
         atomic::{AtomicU32, Ordering},
@@ -257,6 +258,7 @@ pub struct Terminal {
     notifier: Notifier,
     search_regex_opt: Option<RegexSearch>,
     search_value: String,
+    shell_pid: Option<u32>,
     size: Size,
     use_bright_bold: bool,
     zoom_adj: i8,
@@ -328,6 +330,10 @@ impl Terminal {
 
         let window_id = 0;
         let pty = tty::new(&options, size.into(), window_id)?;
+        #[cfg(not(windows))]
+        let shell_pid = Some(pty.child().id());
+        #[cfg(windows)]
+        let shell_pid = pty.child_watcher().pid().map(|pid| pid.get());
 
         let pty_event_loop =
             EventLoop::new(term.clone(), event_proxy, pty, options.drain_on_exit, false)?;
@@ -352,6 +358,7 @@ impl Terminal {
             profile_id_opt,
             search_regex_opt: None,
             search_value: String::new(),
+            shell_pid,
             size,
             tab_title_override,
             term,
@@ -407,6 +414,18 @@ impl Terminal {
         self.notifier.notify(input);
     }
 
+    pub fn working_directory(&self) -> Option<PathBuf> {
+        #[cfg(not(windows))]
+        {
+            let shell_pid = self.shell_pid?;
+            fs::read_link(format!("/proc/{shell_pid}/cwd")).ok()
+        }
+        #[cfg(windows)]
+        {
+            None
+        }
+    }
+
     pub fn input_scroll<I: Into<Cow<'static, [u8]>>>(&self, input: I) {
         self.input_no_scroll(input);
         self.scroll(TerminalScroll::Bottom);