// Copyright 2015 James Bostock. See the LICENSE file at the top-level
// directory of this distribution.

// An implementation of the cat(1) command in Rust.
// See http://man.cat-v.org/unix-6th/1/cat
use std::env;
use std::fs::File;
use std::io;
use std::io::Write;
use std::path::Path;

fn cat(filename: &str) -> io::Result<u64> {
    let mut reader = if filename == "-" {
        Box::new(io::stdin()) as Box<io::Read>
    } else {
        Box::new(try!(File::open(Path::new(&filename)))) as Box<io::Read>
    };

    io::copy(& mut reader, & mut io::stdout())
}

fn main() {
    let mut args : Vec<_> = env::args().collect();

    if args.len() == 1 {
        args.push("-".to_string());
    }

    for arg in args.iter().skip(1) {
        match cat(&arg) {
            Ok(_) => {},
            Err(e) => {
                let mut stderr = std::io::stderr();
                writeln!(&mut stderr, "{}: {}", arg, e).unwrap();
            }
        };
    }
}

// Copyright 2015 James Bostock. See the LICENSE file at the top-level
// directory of this distribution.

// An implementation of the cat(1) command in Rust.
// See http://man.cat-v.org/unix-6th/1/cat
use std::env;
use std::fs::File;
use std::io;
use std::path::Path;

fn cat(filename: &str) -> io::Result<u64> {
    let mut reader = if filename == "-" {
        Box::new(io::stdin()) as Box<io::Read>
    } else {
        Box::new(try!(File::open(Path::new(&filename)))) as Box<io::Read>
    };

    io::copy(& mut reader, & mut io::stdout())
}

fn main() {
    let mut args : Vec<_> = env::args().collect();

    if args.len() == 1 {
        args.push("-".to_string());
    }

    for arg in args.iter().skip(1) {
        match cat(&arg) {
            Ok(_) => {},
            Err(e) => {
                println!("{}: {}", arg, e);
            }
        };
    }
}

--- 
+++ 
@@ -6,6 +6,7 @@
 use std::env;
 use std::fs::File;
 use std::io;
+use std::io::Write;
 use std::path::Path;
 
 fn cat(filename: &str) -> io::Result<u64> {
@@ -29,7 +30,8 @@
         match cat(&arg) {
             Ok(_) => {},
             Err(e) => {
-                println!("{}: {}", arg, e);
+                let mut stderr = std::io::stderr();
+                writeln!(&mut stderr, "{}: {}", arg, e).unwrap();
             }
         };
     }
Write error message to standard error.
