std: <ExitStatus as Display>::fmt name the signal it died from

library/std/src/sys/unix/process/process_unix.rs

@@ -695,18 +695,85 @@ impl From<c_int> for ExitStatus {
  }
 }
 
+/// Convert a signal number to a readable, searchable name.
+///
+/// This string should be displayed right after the signal number.
+/// If a signal is unrecognized, it returns the empty string, so that
+/// you just get the number like "0". If it is recognized, you'll get
+/// something like "9 (SIGKILL)".
+fn signal_string(signal: i32) -> &'static str {
+ match signal {
+ libc::SIGHUP => " (SIGHUP)",
+ libc::SIGINT => " (SIGINT)",
+ libc::SIGQUIT => " (SIGQUIT)",
+ libc::SIGILL => " (SIGILL)",
+ libc::SIGTRAP => " (SIGTRAP)",
+ libc::SIGABRT => " (SIGABRT)",
+ libc::SIGBUS => " (SIGBUS)",
+ libc::SIGFPE => " (SIGFPE)",
+ libc::SIGKILL => " (SIGKILL)",
+ libc::SIGUSR1 => " (SIGUSR1)",
+ libc::SIGSEGV => " (SIGSEGV)",
+ libc::SIGUSR2 => " (SIGUSR2)",
+ libc::SIGPIPE => " (SIGPIPE)",
+ libc::SIGALRM => " (SIGALRM)",
+ libc::SIGTERM => " (SIGTERM)",
+ libc::SIGCHLD => " (SIGCHLD)",
+ libc::SIGCONT => " (SIGCONT)",
+ libc::SIGSTOP => " (SIGSTOP)",
+ libc::SIGTSTP => " (SIGTSTP)",
+ libc::SIGTTIN => " (SIGTTIN)",
+ libc::SIGTTOU => " (SIGTTOU)",
+ libc::SIGURG => " (SIGURG)",
+ libc::SIGXCPU => " (SIGXCPU)",
+ libc::SIGXFSZ => " (SIGXFSZ)",
+ libc::SIGVTALRM => " (SIGVTALRM)",
+ libc::SIGPROF => " (SIGPROF)",
+ libc::SIGWINCH => " (SIGWINCH)",
+ libc::SIGIO => " (SIGIO)",
+ libc::SIGSYS => " (SIGSYS)",
+ #[cfg(target_os = "linux")]
+ libc::SIGSTKFLT => " (SIGSTKFLT)",
+ #[cfg(target_os = "linux")]
+ libc::SIGPWR => " (SIGPWR)",
+ #[cfg(any(
+ target_os = "macos",
+ target_os = "ios",
+ target_os = "tvos",
+ target_os = "freebsd",
+ target_os = "netbsd",
+ target_os = "openbsd",
+ target_os = "dragonfly"
+ ))]
+ libc::SIGEMT => " (SIGEMT)",
+ #[cfg(any(
+ target_os = "macos",
+ target_os = "ios",
+ target_os = "tvos",
+ target_os = "freebsd",
+ target_os = "netbsd",
+ target_os = "openbsd",
+ target_os = "dragonfly"
+ ))]
+ libc::SIGINFO => " (SIGINFO)",
+ _ => "",
+ }
+}
+
 impl fmt::Display for ExitStatus {
  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
  if let Some(code) = self.code() {
  write!(f, "exit status: {code}")
  } else if let Some(signal) = self.signal() {
+ let signal_string = signal_string(signal);
  if self.core_dumped() {
- write!(f, "signal: {signal} (core dumped)")
+ write!(f, "signal: {signal}{signal_string} (core dumped)")
  } else {
- write!(f, "signal: {signal}")
+ write!(f, "signal: {signal}{signal_string}")
  }
  } else if let Some(signal) = self.stopped_signal() {
- write!(f, "stopped (not terminated) by signal: {signal}")
+ let signal_string = signal_string(signal);
+ write!(f, "stopped (not terminated) by signal: {signal}{signal_string}")
  } else if self.continued() {
  write!(f, "continued (WIFCONTINUED)")
  } else {

library/std/src/sys/unix/process/process_unix/tests.rs

@@ -14,8 +14,8 @@ fn exitstatus_display_tests() {
 
  let t = |v, s| assert_eq!(s, format!("{}", <ExitStatus as ExitStatusExt>::from_raw(v)));
 
- t(0x0000f, "signal: 15");
- t(0x0008b, "signal: 11 (core dumped)");
+ t(0x0000f, "signal: 15 (SIGTERM)");
+ t(0x0008b, "signal: 11 (SIGSEGV) (core dumped)");
  t(0x00000, "exit status: 0");
  t(0x0ff00, "exit status: 255");
 
@@ -24,7 +24,7 @@ fn exitstatus_display_tests() {
  // The purpose of this test is to test our string formatting, not our understanding of the wait
  // status magic numbers. So restrict these to Linux.
  if cfg!(target_os = "linux") {
- t(0x0137f, "stopped (not terminated) by signal: 19");
+ t(0x0137f, "stopped (not terminated) by signal: 19 (SIGSTOP)");
  t(0x0ffff, "continued (WIFCONTINUED)");
  }