Refactor signal handling in yes, tee, and timeout

Yes, using libc while using nix was a bit redundant.
Upon investigation, duplicated code was found and moved to uucore.

src/uu/tee/src/tee.rs

@@ -11,7 +11,9 @@ use std::io::{copy, sink, stdin, stdout, Error, ErrorKind, Read, Result, Write};
 use std::path::PathBuf;
 use uucore::display::Quotable;
 use uucore::error::UResult;
-use uucore::{format_usage, help_about, help_section, help_usage, show_error};
+use uucore::{
+    format_usage, help_about, help_section, help_usage, show_error, signals::enable_pipe_errors,
+};
 
 // spell-checker:ignore nopipe
 
@@ -150,21 +152,6 @@ fn ignore_interrupts() -> Result<()> {
     Ok(())
 }
 
-#[cfg(unix)]
-fn enable_pipe_errors() -> Result<()> {
-    let ret = unsafe { libc::signal(libc::SIGPIPE, libc::SIG_DFL) };
-    if ret == libc::SIG_ERR {
-        return Err(Error::new(ErrorKind::Other, ""));
-    }
-    Ok(())
-}
-
-#[cfg(not(unix))]
-fn enable_pipe_errors() -> Result<()> {
-    // Do nothing.
-    Ok(())
-}
-
 fn tee(options: &Options) -> Result<()> {
     if options.ignore_interrupts {
         ignore_interrupts()?;

src/uu/timeout/src/timeout.rs

@@ -17,7 +17,7 @@ use std::time::Duration;
 use uucore::display::Quotable;
 use uucore::error::{UClapError, UResult, USimpleError, UUsageError};
 use uucore::process::ChildExt;
-use uucore::signals::{signal_by_name_or_value, signal_name_by_value};
+use uucore::signals::{enable_pipe_errors, signal_by_name_or_value, signal_name_by_value};
 use uucore::{format_usage, show_error};
 
 static ABOUT: &str = "Start COMMAND, and kill it if still running after DURATION.";
@@ -285,21 +285,6 @@ fn preserve_signal_info(signal: libc::c_int) -> libc::c_int {
     signal
 }
 
-#[cfg(unix)]
-fn enable_pipe_errors() -> std::io::Result<()> {
-    let ret = unsafe { libc::signal(libc::SIGPIPE, libc::SIG_DFL) };
-    if ret == libc::SIG_ERR {
-        return Err(std::io::Error::new(std::io::ErrorKind::Other, ""));
-    }
-    Ok(())
-}
-
-#[cfg(not(unix))]
-fn enable_pipe_errors() -> std::io::Result<()> {
-    // Do nothing.
-    Ok(())
-}
-
 /// TODO: Improve exit codes, and make them consistent with the GNU Coreutils exit codes.
 
 fn timeout(

src/uu/yes/Cargo.toml

@@ -16,8 +16,7 @@ path = "src/yes.rs"
 
 [dependencies]
 clap = { workspace=true }
-libc = { workspace=true }
-uucore = { workspace=true, features=["pipes"] }
+uucore = { workspace=true, features=["pipes", "signals"] }
 
 [target.'cfg(any(target_os = "linux", target_os = "android"))'.dependencies]
 nix = { workspace=true }

src/uu/yes/src/yes.rs

@@ -8,11 +8,12 @@
 /* last synced with: yes (GNU coreutils) 8.13 */
 
 use std::borrow::Cow;
-use std::io::{self, Result, Write};
+use std::io::{self, Write};
 
 use clap::{Arg, ArgAction, Command};
+#[cfg(unix)]
 use uucore::error::{UResult, USimpleError};
-use uucore::{format_usage, help_about, help_usage};
+use uucore::{format_usage, help_about, help_usage, signals::enable_pipe_errors};
 
 #[cfg(any(target_os = "linux", target_os = "android"))]
 mod splice;
@@ -69,21 +70,6 @@ fn prepare_buffer<'a>(input: &'a str, buffer: &'a mut [u8; BUF_SIZE]) -> &'a [u8
     }
 }
 
-#[cfg(unix)]
-fn enable_pipe_errors() -> Result<()> {
-    let ret = unsafe { libc::signal(libc::SIGPIPE, libc::SIG_DFL) };
-    if ret == libc::SIG_ERR {
-        return Err(io::Error::new(io::ErrorKind::Other, ""));
-    }
-    Ok(())
-}
-
-#[cfg(not(unix))]
-fn enable_pipe_errors() -> Result<()> {
-    // Do nothing.
-    Ok(())
-}
-
 pub fn exec(bytes: &[u8]) -> io::Result<()> {
     let stdout = io::stdout();
     let mut stdout = stdout.lock();

src/uucore/Cargo.toml

@@ -49,7 +49,7 @@ sm3 = { workspace=true }
 
 [target.'cfg(unix)'.dependencies]
 walkdir = { workspace=true, optional=true }
-nix = { workspace=true, features = ["fs", "uio", "zerocopy"] }
+nix = { workspace=true, features = ["fs", "uio", "zerocopy", "signal"] }
 
 [dev-dependencies]
 clap = { workspace=true }

src/uucore/src/lib/features/signals.rs

@@ -7,6 +7,10 @@
 
 // spell-checker:ignore (vars/api) fcntl setrlimit setitimer
 // spell-checker:ignore (vars/signals) ABRT ALRM CHLD SEGV SIGABRT SIGALRM SIGBUS SIGCHLD SIGCONT SIGEMT SIGFPE SIGHUP SIGILL SIGINFO SIGINT SIGIO SIGIOT SIGKILL SIGPIPE SIGPROF SIGPWR SIGQUIT SIGSEGV SIGSTOP SIGSYS SIGTERM SIGTRAP SIGTSTP SIGTHR SIGTTIN SIGTTOU SIGURG SIGUSR SIGVTALRM SIGWINCH SIGXCPU SIGXFSZ STKFLT PWR THR TSTP TTIN TTOU VTALRM XCPU XFSZ
+use nix::sys::signal::{
+    signal, SigHandler::SigDfl, SigHandler::SigIgn, Signal::SIGINT, Signal::SIGPIPE,
+};
+use std::io::{Error, ErrorKind, Result};
 
 pub static DEFAULT_SIGNAL: usize = 15;
 
@@ -196,6 +200,36 @@ pub fn signal_name_by_value(signal_value: usize) -> Option<&'static str> {
     ALL_SIGNALS.get(signal_value).copied()
 }
 
+#[cfg(unix)]
+pub fn enable_pipe_errors() -> Result<()> {
+    // SAFETY: this function is safe as long as we do not use a custom SigHandler -- we use the default one.
+    match unsafe { signal(SIGPIPE, SigDfl) } {
+        Ok(_) => Ok(()),
+        _ => Err(Error::from(ErrorKind::Other)),
+    }
+}
+
+#[cfg(not(unix))]
+pub fn enable_pipe_errors() -> Result<()> {
+    // Do nothing.
+    Ok(())
+}
+
+#[cfg(unix)]
+pub fn ignore_interrupts() -> Result<()> {
+    // SAFETY: this function is safe as long as we do not use a custom SigHandler -- we use the ignore one.
+    match unsafe { signal(SIGINT, SigIgn) } {
+        Ok(_) => Ok(()),
+        _ => Err(Error::from(ErrorKind::Other)),
+    }
+}
+
+#[cfg(not(unix))]
+pub fn ignore_interrupts() -> Result<()> {
+    // Do nothing.
+    Ok(())
+}
+
 #[test]
 fn signal_by_value() {
     assert_eq!(signal_by_name_or_value("0"), Some(0));