1 // Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // ignore-lexer-test FIXME #15883
13 // FIXME: cover these topics:
14 // path, reader, writer, stream, raii (close not needed),
15 // stdio, print!, println!, file access, process spawning,
19 //! I/O, including files, networking, timers, and processes
21 //! `std::io` provides Rust's basic I/O types,
22 //! for reading and writing to files, TCP, UDP,
23 //! and other types of sockets and pipes,
24 //! manipulating the file system, spawning processes.
28 //! Some examples of obvious things you might want to do
30 //! * Read lines from stdin
35 //! for line in io::stdin().lock().lines() {
36 //! print!("{}", line.unwrap());
40 //! * Read a complete file
43 //! use std::io::File;
45 //! let contents = File::open(&Path::new("message.txt")).read_to_end();
48 //! * Write a line to a file
51 //! # #![allow(unused_must_use)]
52 //! use std::io::File;
54 //! let mut file = File::create(&Path::new("message.txt"));
55 //! file.write(b"hello, file!\n");
57 //! # ::std::io::fs::unlink(&Path::new("message.txt"));
60 //! * Iterate over the lines of a file
63 //! use std::io::BufferedReader;
64 //! use std::io::File;
66 //! let path = Path::new("message.txt");
67 //! let mut file = BufferedReader::new(File::open(&path));
68 //! for line in file.lines() {
69 //! print!("{}", line.unwrap());
73 //! * Pull the lines of a file into a vector of strings
76 //! use std::io::BufferedReader;
77 //! use std::io::File;
79 //! let path = Path::new("message.txt");
80 //! let mut file = BufferedReader::new(File::open(&path));
81 //! let lines: Vec<String> = file.lines().map(|x| x.unwrap()).collect();
84 //! * Make a simple TCP client connection and request
87 //! # #![allow(unused_must_use)]
88 //! use std::io::TcpStream;
90 //! # // connection doesn't fail if a server is running on 8080
91 //! # // locally, we still want to be type checking this code, so lets
92 //! # // just stop it running (#11576)
94 //! let mut socket = TcpStream::connect("127.0.0.1:8080").unwrap();
95 //! socket.write(b"GET / HTTP/1.0\n\n");
96 //! let response = socket.read_to_end();
100 //! * Make a simple TCP server
105 //! # #![allow(dead_code)]
106 //! use std::io::{TcpListener, TcpStream};
107 //! use std::io::{Acceptor, Listener};
108 //! use std::thread::Thread;
110 //! let listener = TcpListener::bind("127.0.0.1:80");
112 //! // bind the listener to the specified address
113 //! let mut acceptor = listener.listen();
115 //! fn handle_client(mut stream: TcpStream) {
117 //! # &mut stream; // silence unused mutability/variable warning
119 //! // accept connections and process them, spawning a new tasks for each one
120 //! for stream in acceptor.incoming() {
122 //! Err(e) => { /* connection failed */ }
124 //! Thread::spawn(move|| {
125 //! // connection succeeded
126 //! handle_client(stream)
132 //! // close the socket server
140 //! I/O is an area where nearly every operation can result in unexpected
141 //! errors. Errors should be painfully visible when they happen, and handling them
142 //! should be easy to work with. It should be convenient to handle specific I/O
143 //! errors, and it should also be convenient to not deal with I/O errors.
145 //! Rust's I/O employs a combination of techniques to reduce boilerplate
146 //! while still providing feedback about errors. The basic strategy:
148 //! * All I/O operations return `IoResult<T>` which is equivalent to
149 //! `Result<T, IoError>`. The `Result` type is defined in the `std::result`
151 //! * If the `Result` type goes unused, then the compiler will by default emit a
152 //! warning about the unused result. This is because `Result` has the
153 //! `#[must_use]` attribute.
154 //! * Common traits are implemented for `IoResult`, e.g.
155 //! `impl<R: Reader> Reader for IoResult<R>`, so that error values do not have
156 //! to be 'unwrapped' before use.
158 //! These features combine in the API to allow for expressions like
159 //! `File::create(&Path::new("diary.txt")).write(b"Met a girl.\n")`
160 //! without having to worry about whether "diary.txt" exists or whether
161 //! the write succeeds. As written, if either `new` or `write_line`
162 //! encounters an error then the result of the entire expression will
165 //! If you wanted to handle the error though you might write:
168 //! # #![allow(unused_must_use)]
169 //! use std::io::File;
171 //! match File::create(&Path::new("diary.txt")).write(b"Met a girl.\n") {
172 //! Ok(()) => (), // succeeded
173 //! Err(e) => println!("failed to write to my diary: {}", e),
176 //! # ::std::io::fs::unlink(&Path::new("diary.txt"));
179 //! So what actually happens if `create` encounters an error?
180 //! It's important to know that what `new` returns is not a `File`
181 //! but an `IoResult<File>`. If the file does not open, then `new` will simply
182 //! return `Err(..)`. Because there is an implementation of `Writer` (the trait
183 //! required ultimately required for types to implement `write_line`) there is no
184 //! need to inspect or unwrap the `IoResult<File>` and we simply call `write_line`
185 //! on it. If `new` returned an `Err(..)` then the followup call to `write_line`
186 //! will also return an error.
190 //! Explicit pattern matching on `IoResult`s can get quite verbose, especially
191 //! when performing many I/O operations. Some examples (like those above) are
192 //! alleviated with extra methods implemented on `IoResult`, but others have more
193 //! complex interdependencies among each I/O operation.
195 //! The `try!` macro from `std::macros` is provided as a method of early-return
196 //! inside `Result`-returning functions. It expands to an early-return on `Err`
197 //! and otherwise unwraps the contained `Ok` value.
199 //! If you wanted to read several `u32`s from a file and return their product:
202 //! use std::io::{File, IoResult};
204 //! fn file_product(p: &Path) -> IoResult<u32> {
205 //! let mut f = File::open(p);
206 //! let x1 = try!(f.read_le_u32());
207 //! let x2 = try!(f.read_le_u32());
212 //! match file_product(&Path::new("numbers.bin")) {
213 //! Ok(x) => println!("{}", x),
214 //! Err(e) => println!("Failed to read numbers!")
218 //! With `try!` in `file_product`, each `read_le_u32` need not be directly
219 //! concerned with error handling; instead its caller is responsible for
220 //! responding to errors that may occur while attempting to read the numbers.
223 #![deny(unused_must_use)]
225 pub use self::SeekStyle::*;
226 pub use self::FileMode::*;
227 pub use self::FileAccess::*;
228 pub use self::IoErrorKind::*;
231 use default::Default;
235 use iter::{Iterator, IteratorExt};
240 use option::Option::{Some, None};
244 use result::Result::{Ok, Err};
255 pub use self::stdio::stdin;
256 pub use self::stdio::stdout;
257 pub use self::stdio::stderr;
258 pub use self::stdio::print;
259 pub use self::stdio::println;
261 pub use self::fs::File;
262 pub use self::timer::Timer;
263 pub use self::net::ip::IpAddr;
264 pub use self::net::tcp::TcpListener;
265 pub use self::net::tcp::TcpStream;
266 pub use self::pipe::PipeStream;
267 pub use self::process::{Process, Command};
268 pub use self::tempfile::TempDir;
270 pub use self::mem::{MemReader, BufReader, MemWriter, BufWriter};
271 pub use self::buffered::{BufferedReader, BufferedWriter, BufferedStream,
273 pub use self::comm_adapters::{ChanReader, ChanWriter};
292 /// The default buffer size for various I/O operations
293 // libuv recommends 64k buffers to maximize throughput
294 // https://groups.google.com/forum/#!topic/libuv/oQO1HJAIDdA
295 const DEFAULT_BUF_SIZE: uint = 1024 * 64;
297 /// A convenient typedef of the return value of any I/O action.
298 pub type IoResult<T> = Result<T, IoError>;
300 /// The type passed to I/O condition handlers to indicate error
304 /// Is something like this sufficient? It's kind of archaic
305 #[derive(PartialEq, Eq, Clone, Show)]
307 /// An enumeration which can be matched against for determining the flavor
309 pub kind: IoErrorKind,
310 /// A human-readable description about the error
311 pub desc: &'static str,
312 /// Detailed information about this error, not always available
313 pub detail: Option<String>
317 /// Convert an `errno` value into an `IoError`.
319 /// If `detail` is `true`, the `detail` field of the `IoError`
320 /// struct is filled with an allocated string describing the error
321 /// in more detail, retrieved from the operating system.
322 pub fn from_errno(errno: uint, detail: bool) -> IoError {
323 let mut err = sys::decode_error(errno as i32);
324 if detail && err.kind == OtherIoError {
325 err.detail = Some(os::error_string(errno).chars()
326 .map(|c| c.to_lowercase()).collect())
331 /// Retrieve the last error to occur as a (detailed) IoError.
333 /// This uses the OS `errno`, and so there should not be any task
334 /// descheduling or migration (other than that performed by the
335 /// operating system) between the call(s) for which errors are
336 /// being checked and the call of this function.
337 pub fn last_error() -> IoError {
338 IoError::from_errno(os::errno() as uint, true)
343 impl fmt::Display for IoError {
344 fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
346 IoError { kind: OtherIoError, desc: "unknown error", detail: Some(ref detail) } =>
347 write!(fmt, "{}", detail),
348 IoError { detail: None, desc, .. } =>
349 write!(fmt, "{}", desc),
350 IoError { detail: Some(ref detail), desc, .. } =>
351 write!(fmt, "{} ({})", desc, detail)
356 impl Error for IoError {
357 fn description(&self) -> &str { self.desc }
360 /// A list specifying general categories of I/O error.
361 #[derive(Copy, PartialEq, Eq, Clone, Show)]
362 pub enum IoErrorKind {
363 /// Any I/O error not part of this list.
365 /// The operation could not complete because end of file was reached.
367 /// The file was not found.
369 /// The file permissions disallowed access to this file.
371 /// A network connection failed for some reason not specified in this list.
373 /// The network operation failed because the network connection was closed.
375 /// The connection was refused by the remote server.
377 /// The connection was reset by the remote server.
379 /// The connection was aborted (terminated) by the remote server.
381 /// The network operation failed because it was not connected yet.
383 /// The operation failed because a pipe was closed.
385 /// A file already existed with that name.
387 /// No file exists at that location.
389 /// The path did not specify the type of file that this operation required. For example,
390 /// attempting to copy a directory with the `fs::copy()` operation will fail with this error.
391 MismatchedFileTypeForOperation,
392 /// The operation temporarily failed (for example, because a signal was received), and retrying
395 /// No I/O functionality is available for this task.
397 /// A parameter was incorrect in a way that caused an I/O error not part of this list.
399 /// The I/O operation's timeout expired, causing it to be canceled.
401 /// This write operation failed to write all of its data.
403 /// Normally the write() method on a Writer guarantees that all of its data
404 /// has been written, but some operations may be terminated after only
405 /// partially writing some data. An example of this is a timed out write
406 /// which successfully wrote a known number of bytes, but bailed out after
409 /// The payload contained as part of this variant is the number of bytes
410 /// which are known to have been successfully written.
412 /// The Reader returned 0 bytes from `read()` too many times.
416 /// A trait that lets you add a `detail` to an IoError easily
417 trait UpdateIoError<T> {
418 /// Returns an IoError with updated description and detail
419 fn update_err<D>(self, desc: &'static str, detail: D) -> Self where
420 D: FnOnce(&IoError) -> String;
422 /// Returns an IoError with updated detail
423 fn update_detail<D>(self, detail: D) -> Self where
424 D: FnOnce(&IoError) -> String;
426 /// Returns an IoError with update description
427 fn update_desc(self, desc: &'static str) -> Self;
430 impl<T> UpdateIoError<T> for IoResult<T> {
431 fn update_err<D>(self, desc: &'static str, detail: D) -> IoResult<T> where
432 D: FnOnce(&IoError) -> String,
434 self.map_err(move |mut e| {
435 let detail = detail(&e);
437 e.detail = Some(detail);
442 fn update_detail<D>(self, detail: D) -> IoResult<T> where
443 D: FnOnce(&IoError) -> String,
445 self.map_err(move |mut e| { e.detail = Some(detail(&e)); e })
448 fn update_desc(self, desc: &'static str) -> IoResult<T> {
449 self.map_err(|mut e| { e.desc = desc; e })
453 static NO_PROGRESS_LIMIT: uint = 1000;
455 /// A trait for objects which are byte-oriented streams. Readers are defined by
456 /// one method, `read`. This function will block until data is available,
457 /// filling in the provided buffer with any data read.
459 /// Readers are intended to be composable with one another. Many objects
460 /// throughout the I/O and related libraries take and provide types which
461 /// implement the `Reader` trait.
464 // Only method which need to get implemented for this trait
466 /// Read bytes, up to the length of `buf` and place them in `buf`.
467 /// Returns the number of bytes read. The number of bytes read may
468 /// be less than the number requested, even 0. Returns `Err` on EOF.
472 /// If an error occurs during this I/O operation, then it is returned as
473 /// `Err(IoError)`. Note that end-of-file is considered an error, and can be
474 /// inspected for in the error's `kind` field. Also note that reading 0
475 /// bytes is not considered an error in all circumstances
477 /// # Implementation Note
479 /// When implementing this method on a new Reader, you are strongly encouraged
480 /// not to return 0 if you can avoid it.
481 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint>;
483 // Convenient helper methods based on the above methods
485 /// Reads at least `min` bytes and places them in `buf`.
486 /// Returns the number of bytes read.
488 /// This will continue to call `read` until at least `min` bytes have been
489 /// read. If `read` returns 0 too many times, `NoProgress` will be
494 /// If an error occurs at any point, that error is returned, and no further
496 fn read_at_least(&mut self, min: uint, buf: &mut [u8]) -> IoResult<uint> {
499 detail: Some(String::from_str("the buffer is too short")),
500 ..standard_error(InvalidInput)
507 match self.read(buf.slice_from_mut(read)) {
510 if zeroes >= NO_PROGRESS_LIMIT {
511 return Err(standard_error(NoProgress));
518 err@Err(_) => return err
525 /// Reads a single byte. Returns `Err` on EOF.
526 fn read_byte(&mut self) -> IoResult<u8> {
528 try!(self.read_at_least(1, &mut buf));
532 /// Reads up to `len` bytes and appends them to a vector.
533 /// Returns the number of bytes read. The number of bytes read may be
534 /// less than the number requested, even 0. Returns Err on EOF.
538 /// If an error occurs during this I/O operation, then it is returned
539 /// as `Err(IoError)`. See `read()` for more details.
540 fn push(&mut self, len: uint, buf: &mut Vec<u8>) -> IoResult<uint> {
541 let start_len = buf.len();
545 let s = unsafe { slice_vec_capacity(buf, start_len, start_len + len) };
548 unsafe { buf.set_len(start_len + n) };
552 /// Reads at least `min` bytes, but no more than `len`, and appends them to
554 /// Returns the number of bytes read.
556 /// This will continue to call `read` until at least `min` bytes have been
557 /// read. If `read` returns 0 too many times, `NoProgress` will be
562 /// If an error occurs at any point, that error is returned, and no further
564 fn push_at_least(&mut self, min: uint, len: uint, buf: &mut Vec<u8>) -> IoResult<uint> {
567 detail: Some(String::from_str("the buffer is too short")),
568 ..standard_error(InvalidInput)
572 let start_len = buf.len();
575 // we can't just use self.read_at_least(min, slice) because we need to push
576 // successful reads onto the vector before any returned errors.
581 let s = unsafe { slice_vec_capacity(buf, start_len + read, start_len + len) };
582 try!(self.read_at_least(1, s))
584 unsafe { buf.set_len(start_len + read) };
589 /// Reads exactly `len` bytes and gives you back a new vector of length
594 /// Fails with the same conditions as `read`. Additionally returns error
595 /// on EOF. Note that if an error is returned, then some number of bytes may
596 /// have already been consumed from the underlying reader, and they are lost
597 /// (not returned as part of the error). If this is unacceptable, then it is
598 /// recommended to use the `push_at_least` or `read` methods.
599 fn read_exact(&mut self, len: uint) -> IoResult<Vec<u8>> {
600 let mut buf = Vec::with_capacity(len);
601 match self.push_at_least(len, len, &mut buf) {
607 /// Reads all remaining bytes from the stream.
611 /// Returns any non-EOF error immediately. Previously read bytes are
612 /// discarded when an error is returned.
614 /// When EOF is encountered, all bytes read up to that point are returned.
615 fn read_to_end(&mut self) -> IoResult<Vec<u8>> {
616 let mut buf = Vec::with_capacity(DEFAULT_BUF_SIZE);
618 match self.push_at_least(1, DEFAULT_BUF_SIZE, &mut buf) {
620 Err(ref e) if e.kind == EndOfFile => break,
621 Err(e) => return Err(e)
627 /// Reads all of the remaining bytes of this stream, interpreting them as a
628 /// UTF-8 encoded stream. The corresponding string is returned.
632 /// This function returns all of the same errors as `read_to_end` with an
633 /// additional error if the reader's contents are not a valid sequence of
635 fn read_to_string(&mut self) -> IoResult<String> {
636 self.read_to_end().and_then(|s| {
637 match String::from_utf8(s) {
639 Err(_) => Err(standard_error(InvalidInput)),
644 // Byte conversion helpers
646 /// Reads `n` little-endian unsigned integer bytes.
648 /// `n` must be between 1 and 8, inclusive.
649 fn read_le_uint_n(&mut self, nbytes: uint) -> IoResult<u64> {
650 assert!(nbytes > 0 && nbytes <= 8);
656 val += (try!(self.read_u8()) as u64) << pos;
663 /// Reads `n` little-endian signed integer bytes.
665 /// `n` must be between 1 and 8, inclusive.
666 fn read_le_int_n(&mut self, nbytes: uint) -> IoResult<i64> {
667 self.read_le_uint_n(nbytes).map(|i| extend_sign(i, nbytes))
670 /// Reads `n` big-endian unsigned integer bytes.
672 /// `n` must be between 1 and 8, inclusive.
673 fn read_be_uint_n(&mut self, nbytes: uint) -> IoResult<u64> {
674 assert!(nbytes > 0 && nbytes <= 8);
680 val += (try!(self.read_u8()) as u64) << i * 8;
685 /// Reads `n` big-endian signed integer bytes.
687 /// `n` must be between 1 and 8, inclusive.
688 fn read_be_int_n(&mut self, nbytes: uint) -> IoResult<i64> {
689 self.read_be_uint_n(nbytes).map(|i| extend_sign(i, nbytes))
692 /// Reads a little-endian unsigned integer.
694 /// The number of bytes returned is system-dependent.
695 fn read_le_uint(&mut self) -> IoResult<uint> {
696 self.read_le_uint_n(uint::BYTES).map(|i| i as uint)
699 /// Reads a little-endian integer.
701 /// The number of bytes returned is system-dependent.
702 fn read_le_int(&mut self) -> IoResult<int> {
703 self.read_le_int_n(int::BYTES).map(|i| i as int)
706 /// Reads a big-endian unsigned integer.
708 /// The number of bytes returned is system-dependent.
709 fn read_be_uint(&mut self) -> IoResult<uint> {
710 self.read_be_uint_n(uint::BYTES).map(|i| i as uint)
713 /// Reads a big-endian integer.
715 /// The number of bytes returned is system-dependent.
716 fn read_be_int(&mut self) -> IoResult<int> {
717 self.read_be_int_n(int::BYTES).map(|i| i as int)
720 /// Reads a big-endian `u64`.
722 /// `u64`s are 8 bytes long.
723 fn read_be_u64(&mut self) -> IoResult<u64> {
724 self.read_be_uint_n(8)
727 /// Reads a big-endian `u32`.
729 /// `u32`s are 4 bytes long.
730 fn read_be_u32(&mut self) -> IoResult<u32> {
731 self.read_be_uint_n(4).map(|i| i as u32)
734 /// Reads a big-endian `u16`.
736 /// `u16`s are 2 bytes long.
737 fn read_be_u16(&mut self) -> IoResult<u16> {
738 self.read_be_uint_n(2).map(|i| i as u16)
741 /// Reads a big-endian `i64`.
743 /// `i64`s are 8 bytes long.
744 fn read_be_i64(&mut self) -> IoResult<i64> {
745 self.read_be_int_n(8)
748 /// Reads a big-endian `i32`.
750 /// `i32`s are 4 bytes long.
751 fn read_be_i32(&mut self) -> IoResult<i32> {
752 self.read_be_int_n(4).map(|i| i as i32)
755 /// Reads a big-endian `i16`.
757 /// `i16`s are 2 bytes long.
758 fn read_be_i16(&mut self) -> IoResult<i16> {
759 self.read_be_int_n(2).map(|i| i as i16)
762 /// Reads a big-endian `f64`.
764 /// `f64`s are 8 byte, IEEE754 double-precision floating point numbers.
765 fn read_be_f64(&mut self) -> IoResult<f64> {
766 self.read_be_u64().map(|i| unsafe {
767 transmute::<u64, f64>(i)
771 /// Reads a big-endian `f32`.
773 /// `f32`s are 4 byte, IEEE754 single-precision floating point numbers.
774 fn read_be_f32(&mut self) -> IoResult<f32> {
775 self.read_be_u32().map(|i| unsafe {
776 transmute::<u32, f32>(i)
780 /// Reads a little-endian `u64`.
782 /// `u64`s are 8 bytes long.
783 fn read_le_u64(&mut self) -> IoResult<u64> {
784 self.read_le_uint_n(8)
787 /// Reads a little-endian `u32`.
789 /// `u32`s are 4 bytes long.
790 fn read_le_u32(&mut self) -> IoResult<u32> {
791 self.read_le_uint_n(4).map(|i| i as u32)
794 /// Reads a little-endian `u16`.
796 /// `u16`s are 2 bytes long.
797 fn read_le_u16(&mut self) -> IoResult<u16> {
798 self.read_le_uint_n(2).map(|i| i as u16)
801 /// Reads a little-endian `i64`.
803 /// `i64`s are 8 bytes long.
804 fn read_le_i64(&mut self) -> IoResult<i64> {
805 self.read_le_int_n(8)
808 /// Reads a little-endian `i32`.
810 /// `i32`s are 4 bytes long.
811 fn read_le_i32(&mut self) -> IoResult<i32> {
812 self.read_le_int_n(4).map(|i| i as i32)
815 /// Reads a little-endian `i16`.
817 /// `i16`s are 2 bytes long.
818 fn read_le_i16(&mut self) -> IoResult<i16> {
819 self.read_le_int_n(2).map(|i| i as i16)
822 /// Reads a little-endian `f64`.
824 /// `f64`s are 8 byte, IEEE754 double-precision floating point numbers.
825 fn read_le_f64(&mut self) -> IoResult<f64> {
826 self.read_le_u64().map(|i| unsafe {
827 transmute::<u64, f64>(i)
831 /// Reads a little-endian `f32`.
833 /// `f32`s are 4 byte, IEEE754 single-precision floating point numbers.
834 fn read_le_f32(&mut self) -> IoResult<f32> {
835 self.read_le_u32().map(|i| unsafe {
836 transmute::<u32, f32>(i)
842 /// `u8`s are 1 byte.
843 fn read_u8(&mut self) -> IoResult<u8> {
849 /// `i8`s are 1 byte.
850 fn read_i8(&mut self) -> IoResult<i8> {
851 self.read_byte().map(|i| i as i8)
855 /// A reader which can be converted to a RefReader.
856 pub trait ByRefReader {
857 /// Creates a wrapper around a mutable reference to the reader.
859 /// This is useful to allow applying adaptors while still
860 /// retaining ownership of the original value.
861 fn by_ref<'a>(&'a mut self) -> RefReader<'a, Self>;
864 impl<T: Reader> ByRefReader for T {
865 fn by_ref<'a>(&'a mut self) -> RefReader<'a, T> {
866 RefReader { inner: self }
870 /// A reader which can be converted to bytes.
871 pub trait BytesReader {
872 /// Create an iterator that reads a single byte on
873 /// each iteration, until EOF.
877 /// Any error other than `EndOfFile` that is produced by the underlying Reader
878 /// is returned by the iterator and should be handled by the caller.
879 fn bytes<'r>(&'r mut self) -> extensions::Bytes<'r, Self>;
882 impl<T: Reader> BytesReader for T {
883 fn bytes<'r>(&'r mut self) -> extensions::Bytes<'r, T> {
884 extensions::Bytes::new(self)
888 impl<'a> Reader for Box<Reader+'a> {
889 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> {
890 let reader: &mut Reader = &mut **self;
895 impl<'a> Reader for &'a mut (Reader+'a) {
896 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> { (*self).read(buf) }
899 /// Returns a slice of `v` between `start` and `end`.
901 /// Similar to `slice()` except this function only bounds the slice on the
902 /// capacity of `v`, not the length.
906 /// Panics when `start` or `end` point outside the capacity of `v`, or when
908 // Private function here because we aren't sure if we want to expose this as
909 // API yet. If so, it should be a method on Vec.
910 unsafe fn slice_vec_capacity<'a, T>(v: &'a mut Vec<T>, start: uint, end: uint) -> &'a mut [T] {
914 assert!(start <= end);
915 assert!(end <= v.capacity());
917 data: v.as_ptr().offset(start as int),
922 /// A `RefReader` is a struct implementing `Reader` which contains a reference
923 /// to another reader. This is often useful when composing streams.
929 /// use std::io::ByRefReader;
930 /// use std::io::util::LimitReader;
932 /// fn process_input<R: Reader>(r: R) {}
934 /// let mut stream = io::stdin();
936 /// // Only allow the function to process at most one kilobyte of input
938 /// let stream = LimitReader::new(stream.by_ref(), 1024);
939 /// process_input(stream);
942 /// // 'stream' is still available for use here
944 pub struct RefReader<'a, R:'a> {
945 /// The underlying reader which this is referencing
949 impl<'a, R: Reader> Reader for RefReader<'a, R> {
950 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> { self.inner.read(buf) }
953 impl<'a, R: Buffer> Buffer for RefReader<'a, R> {
954 fn fill_buf(&mut self) -> IoResult<&[u8]> { self.inner.fill_buf() }
955 fn consume(&mut self, amt: uint) { self.inner.consume(amt) }
958 fn extend_sign(val: u64, nbytes: uint) -> i64 {
959 let shift = (8 - nbytes) * 8;
960 (val << shift) as i64 >> shift
963 /// A trait for objects which are byte-oriented streams. Writers are defined by
964 /// one method, `write`. This function will block until the provided buffer of
965 /// bytes has been entirely written, and it will return any failures which occur.
967 /// Another commonly overridden method is the `flush` method for writers such as
968 /// buffered writers.
970 /// Writers are intended to be composable with one another. Many objects
971 /// throughout the I/O and related libraries take and provide types which
972 /// implement the `Writer` trait.
974 /// Write the entirety of a given buffer
978 /// If an error happens during the I/O operation, the error is returned as
979 /// `Err`. Note that it is considered an error if the entire buffer could
980 /// not be written, and if an error is returned then it is unknown how much
981 /// data (if any) was actually written.
982 fn write(&mut self, buf: &[u8]) -> IoResult<()>;
984 /// Flush this output stream, ensuring that all intermediately buffered
985 /// contents reach their destination.
987 /// This is by default a no-op and implementers of the `Writer` trait should
988 /// decide whether their stream needs to be buffered or not.
989 fn flush(&mut self) -> IoResult<()> { Ok(()) }
991 /// Writes a formatted string into this writer, returning any error
994 /// This method is primarily used to interface with the `format_args!`
995 /// macro, but it is rare that this should explicitly be called. The
996 /// `write!` macro should be favored to invoke this method instead.
1000 /// This function will return any I/O error reported while formatting.
1001 fn write_fmt(&mut self, fmt: fmt::Arguments) -> IoResult<()> {
1002 // Create a shim which translates a Writer to a fmt::Writer and saves
1003 // off I/O errors. instead of discarding them
1004 struct Adaptor<'a, T: ?Sized +'a> {
1006 error: IoResult<()>,
1009 impl<'a, T: ?Sized + Writer> fmt::Writer for Adaptor<'a, T> {
1010 fn write_str(&mut self, s: &str) -> fmt::Result {
1011 match self.inner.write(s.as_bytes()) {
1014 self.error = Err(e);
1021 let mut output = Adaptor { inner: self, error: Ok(()) };
1022 match fmt::write(&mut output, fmt) {
1024 Err(..) => output.error
1029 /// Write a rust string into this sink.
1031 /// The bytes written will be the UTF-8 encoded version of the input string.
1032 /// If other encodings are desired, it is recommended to compose this stream
1033 /// with another performing the conversion, or to use `write` with a
1034 /// converted byte-array instead.
1036 fn write_str(&mut self, s: &str) -> IoResult<()> {
1037 self.write(s.as_bytes())
1040 /// Writes a string into this sink, and then writes a literal newline (`\n`)
1041 /// byte afterwards. Note that the writing of the newline is *not* atomic in
1042 /// the sense that the call to `write` is invoked twice (once with the
1043 /// string and once with a newline character).
1045 /// If other encodings or line ending flavors are desired, it is recommended
1046 /// that the `write` method is used specifically instead.
1048 fn write_line(&mut self, s: &str) -> IoResult<()> {
1049 self.write_str(s).and_then(|()| self.write(&[b'\n']))
1052 /// Write a single char, encoded as UTF-8.
1054 fn write_char(&mut self, c: char) -> IoResult<()> {
1055 let mut buf = [0u8; 4];
1056 let n = c.encode_utf8(buf.as_mut_slice()).unwrap_or(0);
1057 self.write(&buf[..n])
1060 /// Write the result of passing n through `int::to_str_bytes`.
1062 fn write_int(&mut self, n: int) -> IoResult<()> {
1063 write!(self, "{}", n)
1066 /// Write the result of passing n through `uint::to_str_bytes`.
1068 fn write_uint(&mut self, n: uint) -> IoResult<()> {
1069 write!(self, "{}", n)
1072 /// Write a little-endian uint (number of bytes depends on system).
1074 fn write_le_uint(&mut self, n: uint) -> IoResult<()> {
1075 extensions::u64_to_le_bytes(n as u64, uint::BYTES, |v| self.write(v))
1078 /// Write a little-endian int (number of bytes depends on system).
1080 fn write_le_int(&mut self, n: int) -> IoResult<()> {
1081 extensions::u64_to_le_bytes(n as u64, int::BYTES, |v| self.write(v))
1084 /// Write a big-endian uint (number of bytes depends on system).
1086 fn write_be_uint(&mut self, n: uint) -> IoResult<()> {
1087 extensions::u64_to_be_bytes(n as u64, uint::BYTES, |v| self.write(v))
1090 /// Write a big-endian int (number of bytes depends on system).
1092 fn write_be_int(&mut self, n: int) -> IoResult<()> {
1093 extensions::u64_to_be_bytes(n as u64, int::BYTES, |v| self.write(v))
1096 /// Write a big-endian u64 (8 bytes).
1098 fn write_be_u64(&mut self, n: u64) -> IoResult<()> {
1099 extensions::u64_to_be_bytes(n, 8u, |v| self.write(v))
1102 /// Write a big-endian u32 (4 bytes).
1104 fn write_be_u32(&mut self, n: u32) -> IoResult<()> {
1105 extensions::u64_to_be_bytes(n as u64, 4u, |v| self.write(v))
1108 /// Write a big-endian u16 (2 bytes).
1110 fn write_be_u16(&mut self, n: u16) -> IoResult<()> {
1111 extensions::u64_to_be_bytes(n as u64, 2u, |v| self.write(v))
1114 /// Write a big-endian i64 (8 bytes).
1116 fn write_be_i64(&mut self, n: i64) -> IoResult<()> {
1117 extensions::u64_to_be_bytes(n as u64, 8u, |v| self.write(v))
1120 /// Write a big-endian i32 (4 bytes).
1122 fn write_be_i32(&mut self, n: i32) -> IoResult<()> {
1123 extensions::u64_to_be_bytes(n as u64, 4u, |v| self.write(v))
1126 /// Write a big-endian i16 (2 bytes).
1128 fn write_be_i16(&mut self, n: i16) -> IoResult<()> {
1129 extensions::u64_to_be_bytes(n as u64, 2u, |v| self.write(v))
1132 /// Write a big-endian IEEE754 double-precision floating-point (8 bytes).
1134 fn write_be_f64(&mut self, f: f64) -> IoResult<()> {
1136 self.write_be_u64(transmute(f))
1140 /// Write a big-endian IEEE754 single-precision floating-point (4 bytes).
1142 fn write_be_f32(&mut self, f: f32) -> IoResult<()> {
1144 self.write_be_u32(transmute(f))
1148 /// Write a little-endian u64 (8 bytes).
1150 fn write_le_u64(&mut self, n: u64) -> IoResult<()> {
1151 extensions::u64_to_le_bytes(n, 8u, |v| self.write(v))
1154 /// Write a little-endian u32 (4 bytes).
1156 fn write_le_u32(&mut self, n: u32) -> IoResult<()> {
1157 extensions::u64_to_le_bytes(n as u64, 4u, |v| self.write(v))
1160 /// Write a little-endian u16 (2 bytes).
1162 fn write_le_u16(&mut self, n: u16) -> IoResult<()> {
1163 extensions::u64_to_le_bytes(n as u64, 2u, |v| self.write(v))
1166 /// Write a little-endian i64 (8 bytes).
1168 fn write_le_i64(&mut self, n: i64) -> IoResult<()> {
1169 extensions::u64_to_le_bytes(n as u64, 8u, |v| self.write(v))
1172 /// Write a little-endian i32 (4 bytes).
1174 fn write_le_i32(&mut self, n: i32) -> IoResult<()> {
1175 extensions::u64_to_le_bytes(n as u64, 4u, |v| self.write(v))
1178 /// Write a little-endian i16 (2 bytes).
1180 fn write_le_i16(&mut self, n: i16) -> IoResult<()> {
1181 extensions::u64_to_le_bytes(n as u64, 2u, |v| self.write(v))
1184 /// Write a little-endian IEEE754 double-precision floating-point
1187 fn write_le_f64(&mut self, f: f64) -> IoResult<()> {
1189 self.write_le_u64(transmute(f))
1193 /// Write a little-endian IEEE754 single-precision floating-point
1196 fn write_le_f32(&mut self, f: f32) -> IoResult<()> {
1198 self.write_le_u32(transmute(f))
1202 /// Write a u8 (1 byte).
1204 fn write_u8(&mut self, n: u8) -> IoResult<()> {
1208 /// Write an i8 (1 byte).
1210 fn write_i8(&mut self, n: i8) -> IoResult<()> {
1211 self.write(&[n as u8])
1215 /// A writer which can be converted to a RefWriter.
1216 pub trait ByRefWriter {
1217 /// Creates a wrapper around a mutable reference to the writer.
1219 /// This is useful to allow applying wrappers while still
1220 /// retaining ownership of the original value.
1222 fn by_ref<'a>(&'a mut self) -> RefWriter<'a, Self>;
1225 impl<T: Writer> ByRefWriter for T {
1226 fn by_ref<'a>(&'a mut self) -> RefWriter<'a, T> {
1227 RefWriter { inner: self }
1231 impl<'a> Writer for Box<Writer+'a> {
1233 fn write(&mut self, buf: &[u8]) -> IoResult<()> {
1234 (&mut **self).write(buf)
1238 fn flush(&mut self) -> IoResult<()> {
1239 (&mut **self).flush()
1243 impl<'a> Writer for &'a mut (Writer+'a) {
1245 fn write(&mut self, buf: &[u8]) -> IoResult<()> { (**self).write(buf) }
1248 fn flush(&mut self) -> IoResult<()> { (**self).flush() }
1251 /// A `RefWriter` is a struct implementing `Writer` which contains a reference
1252 /// to another writer. This is often useful when composing streams.
1257 /// use std::io::util::TeeReader;
1258 /// use std::io::{stdin, ByRefWriter};
1260 /// fn process_input<R: Reader>(r: R) {}
1262 /// let mut output = Vec::new();
1265 /// // Don't give ownership of 'output' to the 'tee'. Instead we keep a
1266 /// // handle to it in the outer scope
1267 /// let mut tee = TeeReader::new(stdin(), output.by_ref());
1268 /// process_input(tee);
1271 /// println!("input processed: {:?}", output);
1273 pub struct RefWriter<'a, W:'a> {
1274 /// The underlying writer which this is referencing
1278 impl<'a, W: Writer> Writer for RefWriter<'a, W> {
1280 fn write(&mut self, buf: &[u8]) -> IoResult<()> { self.inner.write(buf) }
1283 fn flush(&mut self) -> IoResult<()> { self.inner.flush() }
1287 /// A Stream is a readable and a writable object. Data written is typically
1288 /// received by the object which reads receive data from.
1289 pub trait Stream: Reader + Writer { }
1291 impl<T: Reader + Writer> Stream for T {}
1293 /// An iterator that reads a line on each iteration,
1294 /// until `.read_line()` encounters `EndOfFile`.
1296 /// # Notes about the Iteration Protocol
1298 /// The `Lines` may yield `None` and thus terminate
1299 /// an iteration, but continue to yield elements if iteration
1300 /// is attempted again.
1304 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1305 /// is returned by the iterator and should be handled by the caller.
1306 pub struct Lines<'r, T:'r> {
1310 impl<'r, T: Buffer> Iterator for Lines<'r, T> {
1311 type Item = IoResult<String>;
1313 fn next(&mut self) -> Option<IoResult<String>> {
1314 match self.buffer.read_line() {
1315 Ok(x) => Some(Ok(x)),
1316 Err(IoError { kind: EndOfFile, ..}) => None,
1317 Err(y) => Some(Err(y))
1322 /// An iterator that reads a utf8-encoded character on each iteration,
1323 /// until `.read_char()` encounters `EndOfFile`.
1325 /// # Notes about the Iteration Protocol
1327 /// The `Chars` may yield `None` and thus terminate
1328 /// an iteration, but continue to yield elements if iteration
1329 /// is attempted again.
1333 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1334 /// is returned by the iterator and should be handled by the caller.
1335 pub struct Chars<'r, T:'r> {
1339 impl<'r, T: Buffer> Iterator for Chars<'r, T> {
1340 type Item = IoResult<char>;
1342 fn next(&mut self) -> Option<IoResult<char>> {
1343 match self.buffer.read_char() {
1344 Ok(x) => Some(Ok(x)),
1345 Err(IoError { kind: EndOfFile, ..}) => None,
1346 Err(y) => Some(Err(y))
1351 /// A Buffer is a type of reader which has some form of internal buffering to
1352 /// allow certain kinds of reading operations to be more optimized than others.
1353 /// This type extends the `Reader` trait with a few methods that are not
1354 /// possible to reasonably implement with purely a read interface.
1355 pub trait Buffer: Reader {
1356 /// Fills the internal buffer of this object, returning the buffer contents.
1357 /// Note that none of the contents will be "read" in the sense that later
1358 /// calling `read` may return the same contents.
1360 /// The `consume` function must be called with the number of bytes that are
1361 /// consumed from this buffer returned to ensure that the bytes are never
1366 /// This function will return an I/O error if the underlying reader was
1367 /// read, but returned an error. Note that it is not an error to return a
1368 /// 0-length buffer.
1369 fn fill_buf<'a>(&'a mut self) -> IoResult<&'a [u8]>;
1371 /// Tells this buffer that `amt` bytes have been consumed from the buffer,
1372 /// so they should no longer be returned in calls to `read`.
1373 fn consume(&mut self, amt: uint);
1375 /// Reads the next line of input, interpreted as a sequence of UTF-8
1376 /// encoded Unicode codepoints. If a newline is encountered, then the
1377 /// newline is contained in the returned string.
1382 /// use std::io::BufReader;
1384 /// let mut reader = BufReader::new(b"hello\nworld");
1385 /// assert_eq!("hello\n", &*reader.read_line().unwrap());
1390 /// This function has the same error semantics as `read_until`:
1392 /// * All non-EOF errors will be returned immediately
1393 /// * If an error is returned previously consumed bytes are lost
1394 /// * EOF is only returned if no bytes have been read
1395 /// * Reach EOF may mean that the delimiter is not present in the return
1398 /// Additionally, this function can fail if the line of input read is not a
1399 /// valid UTF-8 sequence of bytes.
1400 fn read_line(&mut self) -> IoResult<String> {
1401 self.read_until(b'\n').and_then(|line|
1402 match String::from_utf8(line) {
1404 Err(_) => Err(standard_error(InvalidInput)),
1409 /// Reads a sequence of bytes leading up to a specified delimiter. Once the
1410 /// specified byte is encountered, reading ceases and the bytes up to and
1411 /// including the delimiter are returned.
1415 /// If any I/O error is encountered other than EOF, the error is immediately
1416 /// returned. Note that this may discard bytes which have already been read,
1417 /// and those bytes will *not* be returned. It is recommended to use other
1418 /// methods if this case is worrying.
1420 /// If EOF is encountered, then this function will return EOF if 0 bytes
1421 /// have been read, otherwise the pending byte buffer is returned. This
1422 /// is the reason that the byte buffer returned may not always contain the
1424 fn read_until(&mut self, byte: u8) -> IoResult<Vec<u8>> {
1425 let mut res = Vec::new();
1430 let available = match self.fill_buf() {
1432 Err(ref e) if res.len() > 0 && e.kind == EndOfFile => {
1436 Err(e) => return Err(e)
1438 match available.iter().position(|&b| b == byte) {
1440 res.push_all(&available[..(i + 1)]);
1445 res.push_all(available);
1446 used = available.len();
1456 /// Reads the next utf8-encoded character from the underlying stream.
1460 /// If an I/O error occurs, or EOF, then this function will return `Err`.
1461 /// This function will also return error if the stream does not contain a
1462 /// valid utf-8 encoded codepoint as the next few bytes in the stream.
1463 fn read_char(&mut self) -> IoResult<char> {
1464 let first_byte = try!(self.read_byte());
1465 let width = unicode::str::utf8_char_width(first_byte);
1466 if width == 1 { return Ok(first_byte as char) }
1467 if width == 0 { return Err(standard_error(InvalidInput)) } // not utf8
1468 let mut buf = [first_byte, 0, 0, 0];
1471 while start < width {
1472 match try!(self.read(buf.slice_mut(start, width))) {
1473 n if n == width - start => break,
1474 n if n < width - start => { start += n; }
1475 _ => return Err(standard_error(InvalidInput)),
1479 match str::from_utf8(&buf[..width]).ok() {
1480 Some(s) => Ok(s.char_at(0)),
1481 None => Err(standard_error(InvalidInput))
1486 /// Extension methods for the Buffer trait which are included in the prelude.
1487 pub trait BufferPrelude {
1488 /// Create an iterator that reads a utf8-encoded character on each iteration
1493 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1494 /// is returned by the iterator and should be handled by the caller.
1495 fn chars<'r>(&'r mut self) -> Chars<'r, Self>;
1497 /// Create an iterator that reads a line on each iteration until EOF.
1501 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1502 /// is returned by the iterator and should be handled by the caller.
1503 fn lines<'r>(&'r mut self) -> Lines<'r, Self>;
1506 impl<T: Buffer> BufferPrelude for T {
1507 fn chars<'r>(&'r mut self) -> Chars<'r, T> {
1508 Chars { buffer: self }
1511 fn lines<'r>(&'r mut self) -> Lines<'r, T> {
1512 Lines { buffer: self }
1516 /// When seeking, the resulting cursor is offset from a base by the offset given
1517 /// to the `seek` function. The base used is specified by this enumeration.
1519 pub enum SeekStyle {
1520 /// Seek from the beginning of the stream
1522 /// Seek from the end of the stream
1524 /// Seek from the current position
1528 /// An object implementing `Seek` internally has some form of cursor which can
1529 /// be moved within a stream of bytes. The stream typically has a fixed size,
1530 /// allowing seeking relative to either end.
1532 /// Return position of file cursor in the stream
1533 fn tell(&self) -> IoResult<u64>;
1535 /// Seek to an offset in a stream
1537 /// A successful seek clears the EOF indicator. Seeking beyond EOF is
1538 /// allowed, but seeking before position 0 is not allowed.
1542 /// * Seeking to a negative offset is considered an error
1543 /// * Seeking past the end of the stream does not modify the underlying
1544 /// stream, but the next write may cause the previous data to be filled in
1545 /// with a bit pattern.
1546 fn seek(&mut self, pos: i64, style: SeekStyle) -> IoResult<()>;
1549 /// A listener is a value that can consume itself to start listening for
1552 /// Doing so produces some sort of Acceptor.
1553 pub trait Listener<T, A: Acceptor<T>> {
1554 /// Spin up the listener and start queuing incoming connections
1558 /// Returns `Err` if this listener could not be bound to listen for
1559 /// connections. In all cases, this listener is consumed.
1560 fn listen(self) -> IoResult<A>;
1563 /// An acceptor is a value that presents incoming connections
1564 pub trait Acceptor<T> {
1565 /// Wait for and accept an incoming connection
1569 /// Returns `Err` if an I/O error is encountered.
1570 fn accept(&mut self) -> IoResult<T>;
1572 /// Create an iterator over incoming connection attempts.
1574 /// Note that I/O errors will be yielded by the iterator itself.
1575 fn incoming<'r>(&'r mut self) -> IncomingConnections<'r, Self> {
1576 IncomingConnections { inc: self }
1580 /// An infinite iterator over incoming connection attempts.
1581 /// Calling `next` will block the task until a connection is attempted.
1583 /// Since connection attempts can continue forever, this iterator always returns
1584 /// `Some`. The `Some` contains the `IoResult` representing whether the
1585 /// connection attempt was successful. A successful connection will be wrapped
1586 /// in `Ok`. A failed connection is represented as an `Err`.
1587 pub struct IncomingConnections<'a, A: ?Sized +'a> {
1592 impl<'a, T, A: ?Sized + Acceptor<T>> Iterator for IncomingConnections<'a, A> {
1593 type Item = IoResult<T>;
1595 fn next(&mut self) -> Option<IoResult<T>> {
1596 Some(self.inc.accept())
1600 /// Creates a standard error for a commonly used flavor of error. The `detail`
1601 /// field of the returned error will always be `None`.
1608 /// let eof = io::standard_error(io::EndOfFile);
1609 /// let einval = io::standard_error(io::InvalidInput);
1611 pub fn standard_error(kind: IoErrorKind) -> IoError {
1612 let desc = match kind {
1613 EndOfFile => "end of file",
1614 IoUnavailable => "I/O is unavailable",
1615 InvalidInput => "invalid input",
1616 OtherIoError => "unknown I/O error",
1617 FileNotFound => "file not found",
1618 PermissionDenied => "permission denied",
1619 ConnectionFailed => "connection failed",
1620 Closed => "stream is closed",
1621 ConnectionRefused => "connection refused",
1622 ConnectionReset => "connection reset",
1623 ConnectionAborted => "connection aborted",
1624 NotConnected => "not connected",
1625 BrokenPipe => "broken pipe",
1626 PathAlreadyExists => "file already exists",
1627 PathDoesntExist => "no such file",
1628 MismatchedFileTypeForOperation => "mismatched file type",
1629 ResourceUnavailable => "resource unavailable",
1630 TimedOut => "operation timed out",
1631 ShortWrite(..) => "short write",
1632 NoProgress => "no progress",
1641 /// A mode specifies how a file should be opened or created. These modes are
1642 /// passed to `File::open_mode` and are used to control where the file is
1643 /// positioned when it is initially opened.
1644 #[derive(Copy, Clone, PartialEq, Eq, Show)]
1646 /// Opens a file positioned at the beginning.
1648 /// Opens a file positioned at EOF.
1650 /// Opens a file, truncating it if it already exists.
1654 /// Access permissions with which the file should be opened. `File`s
1655 /// opened with `Read` will return an error if written to.
1656 #[derive(Copy, Clone, PartialEq, Eq, Show)]
1657 pub enum FileAccess {
1658 /// Read-only access, requests to write will result in an error
1660 /// Write-only access, requests to read will result in an error
1662 /// Read-write access, no requests are denied by default
1666 /// Different kinds of files which can be identified by a call to stat
1667 #[derive(Copy, PartialEq, Show, Hash, Clone)]
1669 /// This is a normal file, corresponding to `S_IFREG`
1672 /// This file is a directory, corresponding to `S_IFDIR`
1675 /// This file is a named pipe, corresponding to `S_IFIFO`
1678 /// This file is a block device, corresponding to `S_IFBLK`
1681 /// This file is a symbolic link to another file, corresponding to `S_IFLNK`
1684 /// The type of this file is not recognized as one of the other categories
1688 /// A structure used to describe metadata information about a file. This
1689 /// structure is created through the `stat` method on a `Path`.
1694 /// # #![allow(unstable)]
1696 /// use std::io::fs::PathExtensions;
1698 /// let info = match Path::new("foo.txt").stat() {
1699 /// Ok(stat) => stat,
1700 /// Err(e) => panic!("couldn't read foo.txt: {}", e),
1703 /// println!("byte size: {}", info.size);
1705 #[derive(Copy, Hash)]
1706 pub struct FileStat {
1707 /// The size of the file, in bytes
1709 /// The kind of file this path points to (directory, file, pipe, etc.)
1711 /// The file permissions currently on the file
1712 pub perm: FilePermission,
1714 // FIXME(#10301): These time fields are pretty useless without an actual
1715 // time representation, what are the milliseconds relative
1718 /// The time that the file was created at, in platform-dependent
1721 /// The time that this file was last modified, in platform-dependent
1724 /// The time that this file was last accessed, in platform-dependent
1728 /// Information returned by stat() which is not guaranteed to be
1729 /// platform-independent. This information may be useful on some platforms,
1730 /// but it may have different meanings or no meaning at all on other
1733 /// Usage of this field is discouraged, but if access is desired then the
1734 /// fields are located here.
1736 pub unstable: UnstableFileStat,
1739 /// This structure represents all of the possible information which can be
1740 /// returned from a `stat` syscall which is not contained in the `FileStat`
1741 /// structure. This information is not necessarily platform independent, and may
1742 /// have different meanings or no meaning at all on some platforms.
1744 #[derive(Copy, Hash)]
1745 pub struct UnstableFileStat {
1746 /// The ID of the device containing the file.
1748 /// The file serial number.
1752 /// The number of hard links to this file.
1754 /// The user ID of the file.
1756 /// The group ID of the file.
1758 /// The optimal block size for I/O.
1760 /// The blocks allocated for this file.
1762 /// User-defined flags for the file.
1764 /// The file generation number.
1770 /// A set of permissions for a file or directory is represented by a set of
1771 /// flags which are or'd together.
1773 flags FilePermission: u32 {
1774 const USER_READ = 0o400,
1775 const USER_WRITE = 0o200,
1776 const USER_EXECUTE = 0o100,
1777 const GROUP_READ = 0o040,
1778 const GROUP_WRITE = 0o020,
1779 const GROUP_EXECUTE = 0o010,
1780 const OTHER_READ = 0o004,
1781 const OTHER_WRITE = 0o002,
1782 const OTHER_EXECUTE = 0o001,
1784 const USER_RWX = USER_READ.bits | USER_WRITE.bits | USER_EXECUTE.bits,
1785 const GROUP_RWX = GROUP_READ.bits | GROUP_WRITE.bits | GROUP_EXECUTE.bits,
1786 const OTHER_RWX = OTHER_READ.bits | OTHER_WRITE.bits | OTHER_EXECUTE.bits,
1788 /// Permissions for user owned files, equivalent to 0644 on unix-like
1790 const USER_FILE = USER_READ.bits | USER_WRITE.bits | GROUP_READ.bits | OTHER_READ.bits,
1792 /// Permissions for user owned directories, equivalent to 0755 on
1793 /// unix-like systems.
1794 const USER_DIR = USER_RWX.bits | GROUP_READ.bits | GROUP_EXECUTE.bits |
1795 OTHER_READ.bits | OTHER_EXECUTE.bits,
1797 /// Permissions for user owned executables, equivalent to 0755
1798 /// on unix-like systems.
1799 const USER_EXEC = USER_DIR.bits,
1801 /// All possible permissions enabled.
1802 const ALL_PERMISSIONS = USER_RWX.bits | GROUP_RWX.bits | OTHER_RWX.bits,
1808 impl Default for FilePermission {
1811 fn default() -> FilePermission { FilePermission::empty() }
1815 impl fmt::Display for FilePermission {
1816 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1817 write!(f, "{:04o}", self.bits)
1823 use self::BadReaderBehavior::*;
1824 use super::{IoResult, Reader, MemReader, NoProgress, InvalidInput, Writer};
1825 use prelude::v1::{Ok, Vec, Buffer, SliceExt};
1828 #[derive(Clone, PartialEq, Show)]
1829 enum BadReaderBehavior {
1834 struct BadReader<T> {
1836 behavior: Vec<BadReaderBehavior>,
1839 impl<T: Reader> BadReader<T> {
1840 fn new(r: T, behavior: Vec<BadReaderBehavior>) -> BadReader<T> {
1841 BadReader { behavior: behavior, r: r }
1845 impl<T: Reader> Reader for BadReader<T> {
1846 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> {
1847 let BadReader { ref mut behavior, ref mut r } = *self;
1849 if behavior.is_empty() {
1850 // fall back on good
1853 match behavior.as_mut_slice()[0] {
1854 GoodBehavior(0) => (),
1855 GoodBehavior(ref mut x) => {
1859 BadBehavior(0) => (),
1860 BadBehavior(ref mut x) => {
1871 fn test_read_at_least() {
1872 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1873 vec![GoodBehavior(uint::MAX)]);
1874 let buf = &mut [0u8; 5];
1875 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1876 assert!(r.read_exact(5).unwrap().len() == 5); // read_exact uses read_at_least
1877 assert!(r.read_at_least(0, buf).is_ok());
1879 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1880 vec![BadBehavior(50), GoodBehavior(uint::MAX)]);
1881 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1883 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1884 vec![BadBehavior(1), GoodBehavior(1),
1885 BadBehavior(50), GoodBehavior(uint::MAX)]);
1886 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1887 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1889 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1890 vec![BadBehavior(uint::MAX)]);
1891 assert_eq!(r.read_at_least(1, buf).unwrap_err().kind, NoProgress);
1893 let mut r = MemReader::new(b"hello, world!".to_vec());
1894 assert_eq!(r.read_at_least(5, buf).unwrap(), 5);
1895 assert_eq!(r.read_at_least(6, buf).unwrap_err().kind, InvalidInput);
1899 fn test_push_at_least() {
1900 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1901 vec![GoodBehavior(uint::MAX)]);
1902 let mut buf = Vec::new();
1903 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1904 assert!(r.push_at_least(0, 5, &mut buf).is_ok());
1906 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1907 vec![BadBehavior(50), GoodBehavior(uint::MAX)]);
1908 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1910 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1911 vec![BadBehavior(1), GoodBehavior(1),
1912 BadBehavior(50), GoodBehavior(uint::MAX)]);
1913 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1914 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1916 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1917 vec![BadBehavior(uint::MAX)]);
1918 assert_eq!(r.push_at_least(1, 5, &mut buf).unwrap_err().kind, NoProgress);
1920 let mut r = MemReader::new(b"hello, world!".to_vec());
1921 assert_eq!(r.push_at_least(5, 1, &mut buf).unwrap_err().kind, InvalidInput);
1928 assert_eq!(format!("{}", USER_READ), "0400");
1929 assert_eq!(format!("{}", USER_FILE), "0644");
1930 assert_eq!(format!("{}", USER_EXEC), "0755");
1931 assert_eq!(format!("{}", USER_RWX), "0700");
1932 assert_eq!(format!("{}", GROUP_RWX), "0070");
1933 assert_eq!(format!("{}", OTHER_RWX), "0007");
1934 assert_eq!(format!("{}", ALL_PERMISSIONS), "0777");
1935 assert_eq!(format!("{}", USER_READ | USER_WRITE | OTHER_WRITE), "0602");
1938 fn _ensure_buffer_is_object_safe<T: Buffer>(x: &T) -> &Buffer {