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 // OpenBSD 5.9 pledge(2) bindings
 // http://www.openbsd.org/cgi-bin/man.cgi/OpenBSD-current/man2/pledge.2
 
 // rustc --crate-type=lib pledge.rs
 // rustc -L . main.rs
 
 //
 // pledge_ffi.rs
 use std::os::raw::c_char;
 use std::os::raw::c_int;
 
 #[link(name = "c")]
 extern {
 	pub fn pledge(promises: *const c_char, paths: *const *const c_char) -> c_int;
 }
 
 //
 // pledge.rs
 #![crate_type = "lib"]
 
 use std::ffi::CString;
 mod pledge_ffi;
 
 pub fn pledge(promises: &str) -> bool {
 	if let Ok(c_str) = CString::new(promises) {
 		unsafe {
 			let result = pledge_ffi::pledge(c_str.as_ptr(), std::ptr::null());
 			return result == 0;
 		}
 	}
 	return false;
 }
 
 //
 // main.rs
 extern crate pledge;
 
 use pledge::pledge;
 
 use std::process::exit;
 use std::fs::File;
 use std::io::Write;
 
 fn main() {
 	let mut stderr = std::io::stderr();
 	// example will crash
 	// change to "stdio rpath"
 	if !pledge("stdio") {
 		writeln!(&mut stderr, "pledge").unwrap();
 		exit(1);
 	}
 
 	println!("Now pledged.");
 
 	// attempt elevation
 	if !pledge("stdio rpath") {
 		writeln!(&mut stderr, "pledge elevation fail").unwrap();
 		//exit(1);
 	}
 	// .. promises were equal or reduced
 
 	println!("Opening a file!");
 	// kernel should abort here, unless promises changed
 	let file = match File::open("/tmp/bogus/file") {
 		Err(_) => exit(1),
 		Ok(file) => file,
 	};
 	drop(file);
 }