Merge pull request #369 from Arcterus/busybox-fixes

Fix more bugs to pass Busybox tests

.busybox-config

@@ -0,0 +1,2 @@
+CONFIG_FEATURE_FANCY_HEAD=y
+CONFIG_UNICODE_SUPPORT=y

Makefile

@@ -268,9 +268,8 @@ $(BUILDDIR)/busybox: $(BUILDDIR)/uutils
 	ln -s $(BUILDDIR)/uutils $(BUILDDIR)/busybox
 
 # This is a busybox-specific config file their test suite wants to parse.
-# For now it's blank.
+$(BUILDDIR)/.config: $(BASEDIR)/.busybox-config $(BUILDDIR)/uutils
-$(BUILDDIR)/.config: $(BUILDDIR)/uutils
+	cp $< $@
-	touch $@
 
 ifeq ($(BUSYBOX_SRC),)
 busytest:

src/common/util.rs

@@ -14,42 +14,41 @@ extern crate libc;
 #[macro_export]
 macro_rules! show_error(
     ($($args:expr),+) => ({
-        safe_write!(&mut ::std::io::stderr(), "{}: error: ", ::NAME);
+        pipe_write!(&mut ::std::io::stderr(), "{}: error: ", ::NAME);
-        safe_writeln!(&mut ::std::io::stderr(), $($args),+);
+        pipe_writeln!(&mut ::std::io::stderr(), $($args),+);
     })
 )
 
 #[macro_export]
 macro_rules! show_warning(
     ($($args:expr),+) => ({
-        safe_write!(&mut ::std::io::stderr(), "{}: warning: ", ::NAME);
+        pipe_write!(&mut ::std::io::stderr(), "{}: warning: ", ::NAME);
-        safe_writeln!(&mut ::std::io::stderr(), $($args),+);
+        pipe_writeln!(&mut ::std::io::stderr(), $($args),+);
     })
 )
 
 #[macro_export]
 macro_rules! show_info(
     ($($args:expr),+) => ({
-        safe_write!(&mut ::std::io::stderr(), "{}: ", ::NAME);
+        pipe_write!(&mut ::std::io::stderr(), "{}: ", ::NAME);
-        safe_writeln!(&mut ::std::io::stderr(), $($args),+);
+        pipe_writeln!(&mut ::std::io::stderr(), $($args),+);
     })
 )
 
 #[macro_export]
 macro_rules! eprint(
-    ($($args:expr),+) => (safe_write!(&mut ::std::io::stderr(), $($args),+))
+    ($($args:expr),+) => (pipe_write!(&mut ::std::io::stderr(), $($args),+))
 )
 
 #[macro_export]
 macro_rules! eprintln(
-    ($($args:expr),+) => (safe_writeln!(&mut ::std::io::stderr(), $($args),+))
+    ($($args:expr),+) => (pipe_writeln!(&mut ::std::io::stderr(), $($args),+))
 )
 
 #[macro_export]
 macro_rules! crash(
     ($exitcode:expr, $($args:expr),+) => ({
-        safe_write!(&mut ::std::io::stderr(), "{}: error: ", ::NAME);
+        show_error!($($args),+);
-        safe_writeln!(&mut ::std::io::stderr(), $($args),+);
         unsafe { ::util::libc::exit($exitcode as ::util::libc::c_int); }
     })
 )
@@ -84,12 +83,78 @@ macro_rules! return_if_err(
     )
 )
 
+// XXX: should the pipe_* macros return an Err just to show the write failed?
+
+#[macro_export]
+macro_rules! pipe_print(
+    ($($args:expr),+) => (
+        match write!(&mut ::std::io::stdout() as &mut Writer, $($args),+) {
+            Ok(_) => true,
+            Err(f) => {
+                if f.kind == ::std::io::BrokenPipe {
+                    false
+                } else {
+                    fail!("{}", f)
+                }
+            }
+        }
+    )
+)
+
+#[macro_export]
+macro_rules! pipe_println(
+    ($($args:expr),+) => (
+        match writeln!(&mut ::std::io::stdout() as &mut Writer, $($args),+) {
+            Ok(_) => true,
+            Err(f) => {
+                if f.kind == ::std::io::BrokenPipe {
+                    false
+                } else {
+                    fail!("{}", f)
+                }
+            }
+        }
+    )
+)
+
+#[macro_export]
+macro_rules! pipe_write(
+    ($fd:expr, $($args:expr),+) => (
+        match write!($fd, $($args),+) {
+            Ok(_) => true,
+            Err(f) => {
+                if f.kind == ::std::io::BrokenPipe {
+                    false
+                } else {
+                    fail!("{}", f)
+                }
+            }
+        }
+    )
+)
+
+#[macro_export]
+macro_rules! pipe_writeln(
+    ($fd:expr, $($args:expr),+) => (
+        match write!($fd, $($args),+) {
+            Ok(_) => true,
+            Err(f) => {
+                if f.kind == ::std::io::BrokenPipe {
+                    false
+                } else {
+                    fail!("{}", f)
+                }
+            }
+        }
+    )
+)
+
 #[macro_export]
 macro_rules! safe_write(
     ($fd:expr, $($args:expr),+) => (
         match write!($fd, $($args),+) {
             Ok(_) => {}
-            Err(f) => { fail!(f.to_string()); }
+            Err(f) => fail!(f.to_string())
         }
     )
 )
@@ -99,7 +164,7 @@ macro_rules! safe_writeln(
     ($fd:expr, $($args:expr),+) => (
         match writeln!($fd, $($args),+) {
             Ok(_) => {}
-            Err(f) => { fail!(f.to_string()); }
+            Err(f) => fail!(f.to_string())
         }
     )
 )

src/fold/fold.rs

@@ -26,7 +26,6 @@ static NAME: &'static str = "fold";
 static VERSION: &'static str = "1.0.0";
 
 pub fn uumain(args: Vec<String>) -> int {
-
     let (args, obs_width) = handle_obsolete(args.as_slice());
     let program = args[0].clone();
 
@@ -98,11 +97,15 @@ fn handle_obsolete(args: &[String]) -> (Vec<String>, Option<String>) {
 fn fold(filenames: Vec<String>, bytes: bool, spaces: bool, width: uint) {
     for filename in filenames.iter() {
         let filename: &str = filename.as_slice();
+        let mut stdin_buf;
+        let mut file_buf;
         let buffer = BufferedReader::new(
             if filename == "-" {
-                box io::stdio::stdin_raw() as Box<Reader>
+                stdin_buf = io::stdio::stdin_raw();
+                &mut stdin_buf as &mut Reader
             } else {
-                box safe_unwrap!(File::open(&Path::new(filename))) as Box<Reader>
+                file_buf = safe_unwrap!(File::open(&Path::new(filename)));
+                &mut file_buf as &mut Reader
             }
         );
         fold_file(buffer, bytes, spaces, width);
@@ -112,19 +115,24 @@ fn fold(filenames: Vec<String>, bytes: bool, spaces: bool, width: uint) {
 fn fold_file<T: io::Reader>(file: BufferedReader<T>, bytes: bool, spaces: bool, width: uint) {
     let mut file = file;
     for line in file.lines() {
-        let line = safe_unwrap!(line);
+        let line_string = safe_unwrap!(line);
-        if line.len() == 1 {
+        let mut line = line_string.as_slice();
+        let len = line.len();
+        if line.char_at(len - 1) == '\n' {
+            if len == 1 {
                 println!("");
                 continue;
+            } else {
+                line = line.slice_to(len - 1);
+            }
         }
-        let line = line.as_slice().slice_to(line.len() - 1);
         if bytes {
             let mut i = 0;
             while i < line.len() {
                 let width = if line.len() - i >= width { width } else { line.len() - i };
                 let slice = {
                     let slice = line.slice(i, i + width);
-                    if spaces && i + width != line.len() {
+                    if spaces && i + width < line.len() {
                         match slice.rfind(|ch: char| ch.is_whitespace()) {
                             Some(m) => slice.slice_to(m + 1),
                             None => slice
@@ -140,11 +148,40 @@ fn fold_file<T: io::Reader>(file: BufferedReader<T>, bytes: bool, spaces: bool,
             let mut output = String::new();
             let mut count = 0;
             for (i, ch) in line.chars().enumerate() {
+                if count >= width {
+                    let (val, ncount) = {
+                        let slice = output.as_slice();
+                        let (out, val, ncount) =
+                            if spaces && i + 1 < line.len() {
+                                match slice.rfind(|ch: char| ch.is_whitespace()) {
+                                    Some(m) => {
+                                        let routput = slice.slice_from(m + 1).to_string();
+                                        let ncount = routput.as_slice().chars().fold(0u, |out, ch: char| {
+                                            out + match ch {
+                                                '\t' => 8,
+                                                '\x08' => if out > 0 { -1 } else { 0 },
+                                                '\r' => return 0,
+                                                _ => 1
+                                            }
+                                        });
+                                        (slice.slice_to(m + 1), routput, ncount)
+                                    },
+                                    None => (slice, "".to_string(), 0)
+                                }
+                            } else {
+                                (slice, "".to_string(), 0)
+                            };
+                        println!("{}", out);
+                        (val, ncount)
+                    };
+                    output = val.into_string();
+                    count = ncount;
+                }
                 match ch {
                     '\t' => {
                         count += 8;
                         if count > width {
-                            println!("{}", output.as_slice());
+                            println!("{}", output);
                             output.truncate(0);
                             count = 8;
                         }
@@ -165,31 +202,9 @@ fn fold_file<T: io::Reader>(file: BufferedReader<T>, bytes: bool, spaces: bool,
                     _ => count += 1
                 };
                 output.push_char(ch);
-                if count == width {
-                    let (val, ncount) = {
-                        let slice = output.as_slice();
-                        let (out, val, ncount) =
-                            if spaces && i + 1 != line.len() {
-                                match slice.rfind(|ch: char| ch.is_whitespace()) {
-                                    Some(m) => {
-                                        let routput = slice.slice_from(m + 1).to_string();
-                                        let ncount = routput.as_slice().chars().fold(0, |out, ch: char| out + if ch == '\t' { 8 } else { 1 });
-                                        (slice.slice_to(m + 1), routput, ncount)
-                                    },
-                                    None => (slice, "".to_string(), 0)
-                                }
-                            } else {
-                                (slice, "".to_string(), 0)
-                            };
-                        println!("{}", out);
-                        (val, ncount)
-                    };
-                    output = val.into_string();
-                    count = ncount;
-                }
             }
             if count > 0 {
-                println!("{}", output);
+                print!("{}", output);
             }
         }
     }

src/hashsum/hashsum.rs

@@ -151,20 +151,20 @@ pub fn uumain(args: Vec<String>) -> int {
 }
 
 fn version() {
-    println!("{} v{}", NAME, VERSION);
+    pipe_println!("{} v{}", NAME, VERSION);
 }
 
 fn usage(program: &str, binary_name: &str, opts: &[getopts::OptGroup]) {
     version();
-    println!("");
+    pipe_println!("");
-    println!("Usage:");
+    pipe_println!("Usage:");
     if is_custom_binary(binary_name) {
-        println!("  {} [OPTION]... [FILE]...", program);
+        pipe_println!("  {} [OPTION]... [FILE]...", program);
     } else {
-        println!("  {} {{--md5|--sha1|--sha224|--sha256|--sha384|--sha512}} [OPTION]... [FILE]...", program);
+        pipe_println!("  {} {{--md5|--sha1|--sha224|--sha256|--sha384|--sha512}} [OPTION]... [FILE]...", program);
     }
-    println!("");
+    pipe_println!("");
-    print!("{}", getopts::usage("Compute and check message digests.", opts));
+    pipe_print!("{}", getopts::usage("Compute and check message digests.", opts));
 }
 
 fn hashsum(algoname: &str, mut digest: Box<Digest>, files: Vec<String>, binary: bool, check: bool, tag: bool, status: bool, quiet: bool, strict: bool, warn: bool) -> Result<(), int> {
@@ -177,15 +177,18 @@ fn hashsum(algoname: &str, mut digest: Box<Digest>, files: Vec<String>, binary:
     };
     for filename in files.iter() {
         let filename: &str = filename.as_slice();
+        let mut stdin_buf;
+        let mut file_buf;
         let mut file = BufferedReader::new(
             if filename == "-" {
-                box stdin_raw() as Box<Reader>
+                stdin_buf = stdin_raw();
+                &mut stdin_buf as &mut Reader
             } else {
-                box safe_unwrap!(File::open(&Path::new(filename))) as Box<Reader>
+                file_buf = safe_unwrap!(File::open(&Path::new(filename)));
+                &mut file_buf as &mut Reader
             }
         );
         if check {
-
             // Set up Regexes for line validation and parsing
             let bytes = digest.output_bits() / 4;
             let gnu_re = safe_unwrap!(
@@ -229,11 +232,11 @@ fn hashsum(algoname: &str, mut digest: Box<Digest>, files: Vec<String>, binary:
                     .as_slice().to_ascii().to_lower();
                 if sum.as_slice() == real_sum.as_slice() {
                     if !quiet {
-                        println!("{}: OK", ck_filename);
+                        pipe_println!("{}: OK", ck_filename);
                     }
                 } else {
                     if !status {
-                        println!("{}: FAILED", ck_filename);
+                        pipe_println!("{}: FAILED", ck_filename);
                     }
                     failed += 1;
                 }
@@ -241,9 +244,9 @@ fn hashsum(algoname: &str, mut digest: Box<Digest>, files: Vec<String>, binary:
         } else {
             let sum = safe_unwrap!(digest_reader(&mut digest, &mut file, binary));
             if tag {
-                println!("{} ({}) = {}", algoname, filename, sum);
+                pipe_println!("{} ({}) = {}", algoname, filename, sum);
             } else {
-                println!("{} {}{}", sum, binary_marker, filename);
+                pipe_println!("{} {}{}", sum, binary_marker, filename);
             }
         }
     }

src/head/head.rs

@@ -10,6 +10,8 @@
  * Synced with: https://raw.github.com/avsm/src/master/usr.bin/head/head.c
  */
 
+#![feature(macro_rules)]
+
 extern crate getopts;
 
 use std::char;
@@ -20,10 +22,14 @@ use std::path::Path;
 use std::str::from_utf8;
 use getopts::{optopt, optflag, getopts, usage};
 
-static PROGRAM: &'static str = "head";
+#[path = "../common/util.rs"]
+mod util;
+
+static NAME: &'static str = "head";
 
 pub fn uumain(args: Vec<String>) -> int {
     let mut line_count = 10u;
+    let mut byte_count = 0u;
 
     // handle obsolete -number syntax
     let options = match obsolete(args.tail()) {
@@ -34,7 +40,8 @@ pub fn uumain(args: Vec<String>) -> int {
     let args = options;
 
     let possible_options = [
-        optopt("n", "number", "Number of lines to print", "n"),
+        optopt("c", "bytes", "Print the first K bytes.  With the leading '-', print all but the last K bytes", "[-]K"),
+        optopt("n", "lines", "Print the first K lines.  With the leading '-', print all but the last K lines", "[-]K"),
         optflag("h", "help", "help"),
         optflag("V", "version", "version")
     ];
@@ -42,32 +49,58 @@ pub fn uumain(args: Vec<String>) -> int {
     let given_options = match getopts(args.as_slice(), possible_options) {
         Ok (m) => { m }
         Err(_) => {
-            println!("{:s}", usage(PROGRAM, possible_options));
+            println!("{:s}", usage(NAME, possible_options));
             return 1;
         }
     };
 
     if given_options.opt_present("h") {
-        println!("{:s}", usage(PROGRAM, possible_options));
+        println!("{:s}", usage(NAME, possible_options));
         return 0;
     }
     if given_options.opt_present("V") { version(); return 0 }
 
+    let use_bytes = given_options.opt_present("c");
+
+    // TODO: suffixes (e.g. b, kB, etc.)
     match given_options.opt_str("n") {
         Some(n) => {
+            if use_bytes {
+                show_error!("cannot specify both --bytes and --lines.");
+                return 1;
+            }
             match from_str(n.as_slice()) {
                 Some(m) => { line_count = m }
-                None => {}
+                None => {
+                    show_error!("invalid line count '{}'", n);
+                    return 1;
                 }
             }
+        }
+        None => match given_options.opt_str("c") {
+            Some(count) => match from_str(count.as_slice()) {
+                Some(m) => byte_count = m,
+                None => {
+                    show_error!("invalid byte count '{}'", count);
+                    return 1;
+                }
+            },
             None => {}
+        }
     };
 
     let files = given_options.free;
 
+    let count =
+        if use_bytes {
+            byte_count
+        } else {
+            line_count
+        };
+
     if files.is_empty() {
         let mut buffer = BufferedReader::new(stdin());
-        head(&mut buffer, line_count);
+        head(&mut buffer, count, use_bytes);
     } else {
         let mut multiple = false;
         let mut firstime = true;
@@ -76,18 +109,19 @@ pub fn uumain(args: Vec<String>) -> int {
             multiple = true;
         }
 
-
         for file in files.iter() {
             if multiple {
-                if !firstime { println!(""); }
+                if !firstime { pipe_println!(""); }
-                println!("==> {:s} <==", file.as_slice());
+                pipe_println!("==> {:s} <==", file.as_slice());
             }
             firstime = false;
 
             let path = Path::new(file.as_slice());
             let reader = File::open(&path).unwrap();
             let mut buffer = BufferedReader::new(reader);
-            head(&mut buffer, line_count);
+            if !head(&mut buffer, count, use_bytes) {
+                break;
+            }
         }
     }
 
@@ -98,7 +132,7 @@ pub fn uumain(args: Vec<String>) -> int {
 //
 // In case is found, the options vector will get rid of that object so that
 // getopts works correctly.
-fn obsolete (options: &[String]) -> (Vec<String>, Option<uint>) {
+fn obsolete(options: &[String]) -> (Vec<String>, Option<uint>) {
     let mut options: Vec<String> = Vec::from_slice(options);
     let mut a = 0;
     let b = options.len();
@@ -116,7 +150,7 @@ fn obsolete (options: &[String]) -> (Vec<String>, Option<uint>) {
                 // If this is the last number
                 if pos == len - 1 {
                     options.remove(a);
-                    let number : Option<uint> = from_str(from_utf8(current.slice(1,len)).unwrap());
+                    let number: Option<uint> = from_str(from_utf8(current.slice(1,len)).unwrap());
                     return (options, Some(number.unwrap()));
                 }
             }
@@ -128,10 +162,24 @@ fn obsolete (options: &[String]) -> (Vec<String>, Option<uint>) {
     (options, None)
 }
 
-fn head<T: Reader> (reader: &mut BufferedReader<T>, line_count:uint) {
+// TODO: handle errors on read
-    for line in reader.lines().take(line_count) { print!("{}", line.unwrap()); }
+fn head<T: Reader>(reader: &mut BufferedReader<T>, count: uint, use_bytes: bool) -> bool {
+    if use_bytes {
+        for byte in reader.bytes().take(count) {
+            if !pipe_print!("{}", byte.unwrap() as char) {
+                return false;
+            }
+        }
+    } else {
+        for line in reader.lines().take(count) {
+            if !pipe_print!("{}", line.unwrap()) {
+                return false;
+            }
+        }
+    }
+    true
 }
 
-fn version () {
+fn version() {
     println!("head version 1.0.0");
 }

src/hostname/hostname.rs

@@ -12,12 +12,21 @@
  * https://www.opensource.apple.com/source/shell_cmds/shell_cmds-170/hostname/hostname.c?txt
  */
 
+#![feature(macro_rules)]
+
 extern crate getopts;
 extern crate libc;
 
+use std::collections::hashmap::HashSet;
+use std::io::net::addrinfo;
 use std::str;
 use getopts::{optflag, getopts, usage};
 
+#[path = "../common/util.rs"]
+mod util;
+
+static NAME: &'static str = "hostname";
+
 extern {
     fn gethostname(name: *mut libc::c_char, namelen: libc::size_t) -> libc::c_int;
 }
@@ -36,8 +45,10 @@ pub fn uumain(args: Vec<String>) -> int {
     let program = &args[0];
 
     let options = [
-        optflag("f", "full", "Default option to show full name"),
+        optflag("d", "domain", "Display the name of the DNS domain if possible"),
-        optflag("s", "slice subdomain", "Cuts the subdomain off if any"),
+        optflag("i", "ip-address", "Display the network address(es) of the host"),
+        optflag("f", "fqdn", "Display the FQDN (Fully Qualified Domain Name) (default)"),   // TODO: support --long
+        optflag("s", "short", "Display the short hostname (the portion before the first dot) if possible"),
         optflag("h", "help", "Show help"),
         optflag("V", "version", "Show program's version")
     ];
@@ -57,18 +68,49 @@ pub fn uumain(args: Vec<String>) -> int {
         0 => {
             let hostname = xgethostname();
 
+            if matches.opt_present("i") {
+                match addrinfo::get_host_addresses(hostname.as_slice()) {
+                    Ok(addresses) => {
+                        let mut hashset = HashSet::new();
+                        let mut output = String::new();
+                        for addr in addresses.iter() {
+                            // XXX: not sure why this is necessary...
+                            if !hashset.contains(addr) {
+                                output.push_str(addr.to_string().as_slice());
+                                output.push_str(" ");
+                                hashset.insert(addr.clone());
+                            }
+                        }
+                        let len = output.len();
+                        if len > 0 {
+                            println!("{}", output.as_slice().slice_to(len - 1));
+                        }
+                    }
+                    Err(f) => {
+                        show_error!("{}", f);
+                        return 1;
+                    }
+                }
+            } else {
                 if matches.opt_present("s") {
                     let pos = hostname.as_slice().find_str(".");
                     if pos.is_some() {
                         println!("{:s}", hostname.as_slice().slice_to(pos.unwrap()));
                         return 0;
                     }
+                } else if matches.opt_present("d") {
+                    let pos = hostname.as_slice().find_str(".");
+                    if pos.is_some() {
+                        println!("{}", hostname.as_slice().slice_from(pos.unwrap() + 1));
+                        return 0;
+                    }
                 }
 
-            println!("{:s}", hostname.as_slice());
+                println!("{:s}", hostname);
             }
-        1 => { xsethostname( matches.free.last().unwrap().as_slice() ) }
+        }
-        _ => { help_menu(program.as_slice(), options); }
+        1 => xsethostname(matches.free.last().unwrap().as_slice()),
+        _ => help_menu(program.as_slice(), options)
     };
 
     0

src/seq/seq.rs

@@ -9,27 +9,12 @@ extern crate getopts;
 extern crate libc;
 
 use std::cmp;
-use std::io;
 
 #[path = "../common/util.rs"]
 mod util;
 
 static NAME: &'static str = "seq";
 
-macro_rules! pipe_write(
-    ($($args:expr),+) => (
-        match write!(&mut io::stdout() as &mut Writer, $($args),+) {
-            Ok(_) => {}
-            Err(f) =>
-                if f.kind == io::BrokenPipe {
-                    return
-                } else {
-                    fail!("{}", f.to_string())
-                }
-        }
-    )
-)
-
 #[deriving(Clone)]
 struct SeqOptions {
     separator: String,
@@ -237,27 +222,35 @@ fn print_seq(first: f64, step: f64, last: f64, largest_dec: uint, separator: Str
         let before_dec = istr.as_slice().find('.').unwrap_or(ilen);
         if pad && before_dec < padding {
             for _ in range(0, padding - before_dec) {
-                pipe_write!("0");
+                if !pipe_print!("0") {
+                    return;
                 }
             }
-        pipe_write!("{}", istr);
+        }
+        pipe_print!("{}", istr);
         let mut idec = ilen - before_dec;
         if idec < largest_dec {
             if idec == 0 {
-                pipe_write!(".");
+                if !pipe_print!(".") {
+                    return;
+                }
                 idec += 1;
             }
             for _ in range(idec, largest_dec) {
-                pipe_write!("0")
+                if !pipe_print!("0") {
+                    return;
+                }
             }
         }
         i += 1;
         value = first + i as f64 * step;
         if !done_printing(value, step, last) {
-            pipe_write!("{:s}", separator);
+            if !pipe_print!("{:s}", separator) {
+                return;
+            }
         }
     }
     if (first >= last && step < 0f64) || (first <= last && step > 0f64) {
-        pipe_write!("{:s}", terminator);
+        pipe_print!("{:s}", terminator);
     }
 }

src/uutils/uutils.rs

@@ -54,8 +54,8 @@ fn main() {
         None => (),
     }
 
-    if binary_as_util.ends_with("uutils")
+    if binary_as_util.ends_with("uutils") || binary_as_util.starts_with("uutils") ||
-        || binary_as_util.ends_with("busybox") {
+        binary_as_util.ends_with("busybox") || binary_as_util.starts_with("busybox") {
             // uutils can be called as either "uutils", "busybox"
             // "uutils-suffix" or "busybox-suffix". Not sure
             // what busybox uses the -suffix pattern for.

src/yes/yes.rs

@@ -16,7 +16,7 @@
 extern crate getopts;
 extern crate libc;
 
-use std::io::{print, println};
+use std::io::print;
 
 #[path = "../common/util.rs"]
 mod util;
@@ -60,6 +60,8 @@ pub fn uumain(args: Vec<String>) -> int {
 
 pub fn exec(string: &str) {
     loop {
-        println(string);
+        if !pipe_println!("{}", string) {
+            break;
+        }
     }
 }