From ab0366a07626806cf3b27a857148bd33a0a42c83 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bastian=20K=C3=B6cher?= <bkchr@users.noreply.github.com>
Date: Sun, 29 Mar 2020 14:12:18 +0200
Subject: [PATCH] Add method to `sc-cli` to reset the `SIGPIPE` signal handler
 (#5447)

The signal handler will be reset to the default system one. This means
the program will be exited instead of panicking. This is required to
support piping in the console.
---
 substrate/Cargo.lock                  |  1 +
 substrate/bin/node/cli/src/command.rs |  2 ++
 substrate/client/cli/Cargo.toml       |  3 +++
 substrate/client/cli/src/lib.rs       | 18 ++++++++++++++++++
 4 files changed, 24 insertions(+)

diff --git a/substrate/Cargo.lock b/substrate/Cargo.lock
index b0d6c55686..e87be8f0fb 100644
--- a/substrate/Cargo.lock
+++ b/substrate/Cargo.lock
@@ -5832,6 +5832,7 @@ dependencies = [
  "lazy_static",
  "log 0.4.8",
  "names",
+ "nix",
  "parity-util-mem",
  "regex",
  "rpassword",
diff --git a/substrate/bin/node/cli/src/command.rs b/substrate/bin/node/cli/src/command.rs
index 21584f0898..6e9b5ca575 100644
--- a/substrate/bin/node/cli/src/command.rs
+++ b/substrate/bin/node/cli/src/command.rs
@@ -25,6 +25,8 @@ where
 	I: Iterator<Item = T>,
 	T: Into<std::ffi::OsString> + Clone,
 {
+	sc_cli::reset_signal_pipe_handler()?;
+
 	let args: Vec<_> = args.collect();
 	let opt = sc_cli::from_iter::<Cli, _>(args.clone(), &version);
 
diff --git a/substrate/client/cli/Cargo.toml b/substrate/client/cli/Cargo.toml
index d623d670ad..7b9313c8d6 100644
--- a/substrate/client/cli/Cargo.toml
+++ b/substrate/client/cli/Cargo.toml
@@ -44,6 +44,9 @@ parity-util-mem = { version = "0.6.0", default-features = false, features = ["pr
 [target.'cfg(not(target_os = "unknown"))'.dependencies]
 rpassword = "4.0.1"
 
+[target.'cfg(target_family = "unix")'.dependencies]
+nix = "0.17.0"
+
 [dev-dependencies]
 tempfile = "3.1.0"
 
diff --git a/substrate/client/cli/src/lib.rs b/substrate/client/cli/src/lib.rs
index f94df935a1..18a5991e39 100644
--- a/substrate/client/cli/src/lib.rs
+++ b/substrate/client/cli/src/lib.rs
@@ -221,3 +221,21 @@ fn kill_color(s: &str) -> String {
 	}
 	RE.replace_all(s, "").to_string()
 }
+
+/// Reset the signal pipe (`SIGPIPE`) handler to the default one provided by the system.
+/// This will end the program on `SIGPIPE` instead of panicking.
+///
+/// This should be called before calling any cli method or printing any output.
+pub fn reset_signal_pipe_handler() -> Result<()> {
+	#[cfg(target_family = "unix")]
+	{
+		use nix::sys::signal;
+
+		unsafe {
+			signal::signal(signal::Signal::SIGPIPE, signal::SigHandler::SigDfl)
+				.map_err(|e| Error::Other(e.to_string()))?;
+		}
+	}
+
+	Ok(())
+}