From 5b449f4e1e43bc59109da5a37edf5ec911d3df8e Mon Sep 17 00:00:00 2001
From: Matthias Schiffer <mschiffer@universe-factory.net>
Date: Mon, 13 Apr 2020 02:13:58 +0200
Subject: IO, error handling

---
 safe_libc/src/errno.rs | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 safe_libc/src/errno.rs

(limited to 'safe_libc/src/errno.rs')

diff --git a/safe_libc/src/errno.rs b/safe_libc/src/errno.rs
new file mode 100644
index 0000000..be944d1
--- /dev/null
+++ b/safe_libc/src/errno.rs
@@ -0,0 +1,29 @@
+use crate::string;
+
+use core::fmt;
+
+#[derive(Clone, Copy, Debug)]
+#[repr(transparent)]
+pub struct Errno(pub libc::c_int);
+
+#[inline]
+pub fn errno() -> Errno {
+	unsafe { Errno(*libc::__errno_location()) }
+}
+
+impl fmt::Display for Errno {
+	#[inline]
+	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+		let mut buf = [0u8; 1024];
+		let cstr = unsafe {
+			if libc::strerror_r(self.0, buf.as_mut_ptr().cast(), buf.len()) != 0 {
+				return Err(fmt::Error);
+			}
+			string::CStr::from_bytes_with_nul_unchecked(&buf)
+		};
+		match cstr.to_str() {
+			Err(_) => Err(fmt::Error),
+			Ok(s) => f.write_str(s),
+		}
+	}
+}
-- 
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