fix(input): handle Ctrl+C via SIGINT signal instead of keypress

CHANGELOG.md

@@ -8,6 +8,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 
 ### Fixed
 
+* Fix Ctrl+C handling to use SIGINT signal instead of keypress #491 - @chiranjeevi-max
 * Update CONTRIBUTING information #438 - @YJDoc2 @cyqsimon
 * Fix new clippy lint #457 - @cyqsimon
 * Apply new clippy lints #468 - @cyqsimon

Cargo.toml

@@ -31,6 +31,7 @@ chrono = "0.4"
 clap-verbosity-flag = "3.0.3"
 clap = { version = "4.5.41", features = ["derive"] }
 crossterm = "0.29.0"
+ctrlc = "3.4"
 derive_more = { version = "2.0.1", features = ["debug"] }
 eyre = "0.6.12"
 itertools = "0.14.0"

src/main.rs

@@ -70,6 +70,11 @@ fn main() -> eyre::Result<()> {
         let _ = crossterm::execute!(&mut stdout, terminal::EnterAlternateScreen);
         let terminal_backend = CrosstermBackend::new(stdout);
         start(terminal_backend, os_input, opts);
+
+        // Ensure terminal is restored after exit (handles SIGINT case).
+        // These operations are idempotent, so safe to call even if 'q' already cleaned up.
+        let _ = terminal::disable_raw_mode();
+        let _ = crossterm::execute!(std::io::stdout(), terminal::LeaveAlternateScreen);
     }
     Ok(())
 }
@@ -96,6 +101,17 @@ where
     let cumulative_time = Arc::new(RwLock::new(Duration::new(0, 0)));
     let table_cycle_offset = Arc::new(AtomicUsize::new(0));
 
+    // handle SIGINT properly instead of as a keypress
+    // see https://github.com/imsnif/bandwhich/issues/487
+    #[cfg(not(test))]
+    {
+        let running = running.clone();
+        ctrlc::set_handler(move || {
+            running.store(false, Ordering::Release);
+        })
+        .expect("failed to set SIGINT handler");
+    }
+
     let mut active_threads = vec![];
 
     let terminal_events = os_input.terminal_events;
@@ -175,7 +191,11 @@ where
             let display_handler = display_handler.thread().clone();
 
             move || {
-                for evt in terminal_events {
+                let mut terminal_events = terminal_events;
+                while running.load(Ordering::Acquire) {
+                    let Some(evt) = terminal_events.next() else {
+                        continue;
+                    };
                     let mut ui = ui.lock().unwrap();
 
                     match evt {
@@ -192,12 +212,6 @@ where
                             );
                         }
                         Event::Key(KeyEvent {
-                            modifiers: KeyModifiers::CONTROL,
-                            code: KeyCode::Char('c'),
-                            kind: KeyEventKind::Press,
-                            ..
-                        })
-                        | Event::Key(KeyEvent {
                             modifiers: KeyModifiers::NONE,
                             code: KeyCode::Char('q'),
                             kind: KeyEventKind::Press,

src/os/shared.rs

@@ -1,10 +1,10 @@
 use std::{
     io::{self, ErrorKind, Write},
     net::Ipv4Addr,
-    time,
+    time::{self, Duration},
 };
 
-use crossterm::event::{read, Event};
+use crossterm::event::{poll, read, Event};
 use eyre::{bail, eyre};
 use itertools::Itertools;
 use log::{debug, warn};
@@ -35,12 +35,25 @@ impl ProcessInfo {
     }
 }
 
+/// Poll timeout for terminal events.
+/// This allows the event loop to periodically check the `running` flag
+/// for graceful shutdown on SIGINT.
+const POLL_TIMEOUT: Duration = Duration::from_millis(100);
+
 pub struct TerminalEvents;
 
 impl Iterator for TerminalEvents {
     type Item = Event;
+    /// Returns the next terminal event, or `None` if no event is available
+    /// within the poll timeout.
+    ///
+    /// Note: `None` here means "no event right now", not "iteration complete".
+    /// The consumer should use `while running` instead of `for evt in ...`.
     fn next(&mut self) -> Option<Event> {
-        read().ok()
+        match poll(POLL_TIMEOUT) {
+            Ok(true) => read().ok(),
+            Ok(false) | Err(_) => None,
+        }
     }
 }
 

src/tests/cases/test_utils.rs

@@ -25,8 +25,8 @@ use crate::{
 pub fn sleep_and_quit_events(sleep_num: usize) -> Box<TerminalEvents> {
     let events = iter::repeat_n(None, sleep_num)
         .chain([Some(Event::Key(KeyEvent::new(
-            KeyCode::Char('c'),
-            KeyModifiers::CONTROL,
+            KeyCode::Char('q'),
+            KeyModifiers::NONE,
         )))])
         .collect();
     Box::new(TerminalEvents::new(events))
@@ -37,8 +37,8 @@ pub fn sleep_resize_and_quit_events(sleep_num: usize) -> Box<TerminalEvents> {
         .chain([
             Some(Event::Resize(100, 100)),
             Some(Event::Key(KeyEvent::new(
-                KeyCode::Char('c'),
-                KeyModifiers::CONTROL,
+                KeyCode::Char('q'),
+                KeyModifiers::NONE,
             ))),
         ])
         .collect();