Replace ctrlc with signal-hooksignal

Replaced the 'ctrlc' crate with 'signal-hook' for handling of SIGINT.
The 'signal_hook::low_level::register' function is actually unsafe.
However, according to
https://docs.rs/signal-hook/latest/signal_hook/low_level/fn.register.html,
it is only unsafe in the case of multithreaded applications. There are
some race conditions as well. For instance, it appears that even when we
fork to a child process, SIGINT is captured on both that process, as
well as the shell.

3 files changed, 17 insertions, 99 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 1098731..5e36732 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -3,32 +3,10 @@
 version = 3
 
 [[package]]
-name = "bitflags"
-version = "2.4.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ed570934406eb16438a4e976b1b4500774099c13b8cb96eec99f620f05090ddf"
-
-[[package]]
-name = "cfg-if"
-version = "1.0.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
-
-[[package]]
-name = "ctrlc"
-version = "3.4.2"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b467862cc8610ca6fc9a1532d7777cee0804e678ab45410897b9396495994a0b"
-dependencies = [
- "nix",
- "windows-sys",
-]
-
-[[package]]
 name = "dwarvish"
 version = "0.0.0"
 dependencies = [
- "ctrlc",
+ "signal-hook",
 ]
 
 [[package]]
@@ -38,78 +16,20 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9c198f91728a82281a64e1f4f9eeb25d82cb32a5de251c6bd1b5154d63a8e7bd"
 
 [[package]]
-name = "nix"
-version = "0.27.1"
+name = "signal-hook"
+version = "0.3.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2eb04e9c688eff1c89d72b407f168cf79bb9e867a9d3323ed6c01519eb9cc053"
+checksum = "8621587d4798caf8eb44879d42e56b9a93ea5dcd315a6487c357130095b62801"
 dependencies = [
- "bitflags",
- "cfg-if",
  "libc",
+ "signal-hook-registry",
 ]
 
 [[package]]
-name = "windows-sys"
-version = "0.52.0"
+name = "signal-hook-registry"
+version = "1.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "282be5f36a8ce781fad8c8ae18fa3f9beff57ec1b52cb3de0789201425d9a33d"
+checksum = "d8229b473baa5980ac72ef434c4415e70c4b5e71b423043adb4ba059f89c99a1"
 dependencies = [
- "windows-targets",
-]
-
-[[package]]
-name = "windows-targets"
-version = "0.52.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8a18201040b24831fbb9e4eb208f8892e1f50a37feb53cc7ff887feb8f50e7cd"
-dependencies = [
- "windows_aarch64_gnullvm",
- "windows_aarch64_msvc",
- "windows_i686_gnu",
- "windows_i686_msvc",
- "windows_x86_64_gnu",
- "windows_x86_64_gnullvm",
- "windows_x86_64_msvc",
+ "libc",
 ]
-
-[[package]]
-name = "windows_aarch64_gnullvm"
-version = "0.52.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cb7764e35d4db8a7921e09562a0304bf2f93e0a51bfccee0bd0bb0b666b015ea"
-
-[[package]]
-name = "windows_aarch64_msvc"
-version = "0.52.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bbaa0368d4f1d2aaefc55b6fcfee13f41544ddf36801e793edbbfd7d7df075ef"
-
-[[package]]
-name = "windows_i686_gnu"
-version = "0.52.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a28637cb1fa3560a16915793afb20081aba2c92ee8af57b4d5f28e4b3e7df313"
-
-[[package]]
-name = "windows_i686_msvc"
-version = "0.52.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ffe5e8e31046ce6230cc7215707b816e339ff4d4d67c65dffa206fd0f7aa7b9a"
-
-[[package]]
-name = "windows_x86_64_gnu"
-version = "0.52.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3d6fa32db2bc4a2f5abeacf2b69f7992cd09dca97498da74a151a3132c26befd"
-
-[[package]]
-name = "windows_x86_64_gnullvm"
-version = "0.52.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1a657e1e9d3f514745a572a6846d3c7aa7dbe1658c056ed9c3344c4109a6949e"
-
-[[package]]
-name = "windows_x86_64_msvc"
-version = "0.52.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dff9641d1cd4be8d1a070daf9e3773c5f67e78b4d9d42263020c057706765c04"
diff --git a/Cargo.toml b/Cargo.toml
index 00fdb24..ae18cfc 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,7 +9,5 @@ description = "A POSIX compliance shell and tiny functional programming language
 name = "dwvsh"
 path = "src/main.rs"
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
 [dependencies]
-ctrlc = "3.4.2"
+signal-hook = "0.3.17"
diff --git a/src/main.rs b/src/main.rs
index db349d3..986e006 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,5 +1,4 @@
 mod recite;
-use ctrlc;
 use recite::path::prefresh;
 use recite::Poem;
 use std::io::{self, Write};
@@ -28,7 +27,6 @@ fn repl(path: &Vec<&Path>, prompt: &str) {
     // Main shell loop
     loop {
         // Output the prompt
-        io::stdout().flush().unwrap();
         print!("{}", prompt);
         io::stdout().flush().unwrap();
 
@@ -83,11 +81,13 @@ fn main() {
     let prompt = "|> ";
 
     // Handle signals
-    ctrlc::set_handler(move || {
-        print!("\n{}", prompt);
-        io::stdout().flush().unwrap();
-    })
-    .expect("dwvsh: signals: unable to set sigint handler");
+    unsafe {
+        signal_hook::low_level::register(signal_hook::consts::SIGINT, move || {
+            print!("\n{}", prompt);
+            io::stdout().flush().unwrap();
+        })
+        .unwrap();
+    };
 
     // Begin evaluating commands
     repl(&path, prompt);