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::*;
232 use default::Default;
233 use error::{FromError, Error};
236 use iter::{Iterator, IteratorExt};
241 use option::Option::{Some, None};
245 use result::Result::{Ok, Err};
256 pub use self::stdio::stdin;
257 pub use self::stdio::stdout;
258 pub use self::stdio::stderr;
259 pub use self::stdio::print;
260 pub use self::stdio::println;
262 pub use self::fs::File;
263 pub use self::timer::Timer;
264 pub use self::net::ip::IpAddr;
265 pub use self::net::tcp::TcpListener;
266 pub use self::net::tcp::TcpStream;
267 pub use self::pipe::PipeStream;
268 pub use self::process::{Process, Command};
269 pub use self::tempfile::TempDir;
271 pub use self::mem::{MemReader, BufReader, MemWriter, BufWriter};
272 pub use self::buffered::{BufferedReader, BufferedWriter, BufferedStream,
274 pub use self::comm_adapters::{ChanReader, ChanWriter};
293 /// The default buffer size for various I/O operations
294 // libuv recommends 64k buffers to maximize throughput
295 // https://groups.google.com/forum/#!topic/libuv/oQO1HJAIDdA
296 const DEFAULT_BUF_SIZE: uint = 1024 * 64;
298 /// A convenient typedef of the return value of any I/O action.
299 pub type IoResult<T> = Result<T, IoError>;
301 /// The type passed to I/O condition handlers to indicate error
305 /// Is something like this sufficient? It's kind of archaic
306 #[derive(PartialEq, Eq, Clone, Show)]
308 /// An enumeration which can be matched against for determining the flavor
310 pub kind: IoErrorKind,
311 /// A human-readable description about the error
312 pub desc: &'static str,
313 /// Detailed information about this error, not always available
314 pub detail: Option<String>
318 /// Convert an `errno` value into an `IoError`.
320 /// If `detail` is `true`, the `detail` field of the `IoError`
321 /// struct is filled with an allocated string describing the error
322 /// in more detail, retrieved from the operating system.
323 pub fn from_errno(errno: uint, detail: bool) -> IoError {
324 let mut err = sys::decode_error(errno as i32);
325 if detail && err.kind == OtherIoError {
326 err.detail = Some(os::error_string(errno).chars()
327 .map(|c| c.to_lowercase()).collect())
332 /// Retrieve the last error to occur as a (detailed) IoError.
334 /// This uses the OS `errno`, and so there should not be any task
335 /// descheduling or migration (other than that performed by the
336 /// operating system) between the call(s) for which errors are
337 /// being checked and the call of this function.
338 pub fn last_error() -> IoError {
339 IoError::from_errno(os::errno() as uint, true)
343 impl fmt::String 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 {
361 fn detail(&self) -> Option<String> {
366 impl FromError<IoError> for Box<Error> {
367 fn from_error(err: IoError) -> Box<Error> {
372 /// A list specifying general categories of I/O error.
373 #[derive(Copy, PartialEq, Eq, Clone, Show)]
374 pub enum IoErrorKind {
375 /// Any I/O error not part of this list.
377 /// The operation could not complete because end of file was reached.
379 /// The file was not found.
381 /// The file permissions disallowed access to this file.
383 /// A network connection failed for some reason not specified in this list.
385 /// The network operation failed because the network connection was closed.
387 /// The connection was refused by the remote server.
389 /// The connection was reset by the remote server.
391 /// The connection was aborted (terminated) by the remote server.
393 /// The network operation failed because it was not connected yet.
395 /// The operation failed because a pipe was closed.
397 /// A file already existed with that name.
399 /// No file exists at that location.
401 /// The path did not specify the type of file that this operation required. For example,
402 /// attempting to copy a directory with the `fs::copy()` operation will fail with this error.
403 MismatchedFileTypeForOperation,
404 /// The operation temporarily failed (for example, because a signal was received), and retrying
407 /// No I/O functionality is available for this task.
409 /// A parameter was incorrect in a way that caused an I/O error not part of this list.
411 /// The I/O operation's timeout expired, causing it to be canceled.
413 /// This write operation failed to write all of its data.
415 /// Normally the write() method on a Writer guarantees that all of its data
416 /// has been written, but some operations may be terminated after only
417 /// partially writing some data. An example of this is a timed out write
418 /// which successfully wrote a known number of bytes, but bailed out after
421 /// The payload contained as part of this variant is the number of bytes
422 /// which are known to have been successfully written.
424 /// The Reader returned 0 bytes from `read()` too many times.
428 /// A trait that lets you add a `detail` to an IoError easily
429 trait UpdateIoError<T> {
430 /// Returns an IoError with updated description and detail
431 fn update_err<D>(self, desc: &'static str, detail: D) -> Self where
432 D: FnOnce(&IoError) -> String;
434 /// Returns an IoError with updated detail
435 fn update_detail<D>(self, detail: D) -> Self where
436 D: FnOnce(&IoError) -> String;
438 /// Returns an IoError with update description
439 fn update_desc(self, desc: &'static str) -> Self;
442 impl<T> UpdateIoError<T> for IoResult<T> {
443 fn update_err<D>(self, desc: &'static str, detail: D) -> IoResult<T> where
444 D: FnOnce(&IoError) -> String,
446 self.map_err(move |mut e| {
447 let detail = detail(&e);
449 e.detail = Some(detail);
454 fn update_detail<D>(self, detail: D) -> IoResult<T> where
455 D: FnOnce(&IoError) -> String,
457 self.map_err(move |mut e| { e.detail = Some(detail(&e)); e })
460 fn update_desc(self, desc: &'static str) -> IoResult<T> {
461 self.map_err(|mut e| { e.desc = desc; e })
465 static NO_PROGRESS_LIMIT: uint = 1000;
467 /// A trait for objects which are byte-oriented streams. Readers are defined by
468 /// one method, `read`. This function will block until data is available,
469 /// filling in the provided buffer with any data read.
471 /// Readers are intended to be composable with one another. Many objects
472 /// throughout the I/O and related libraries take and provide types which
473 /// implement the `Reader` trait.
476 // Only method which need to get implemented for this trait
478 /// Read bytes, up to the length of `buf` and place them in `buf`.
479 /// Returns the number of bytes read. The number of bytes read may
480 /// be less than the number requested, even 0. Returns `Err` on EOF.
484 /// If an error occurs during this I/O operation, then it is returned as
485 /// `Err(IoError)`. Note that end-of-file is considered an error, and can be
486 /// inspected for in the error's `kind` field. Also note that reading 0
487 /// bytes is not considered an error in all circumstances
489 /// # Implementation Note
491 /// When implementing this method on a new Reader, you are strongly encouraged
492 /// not to return 0 if you can avoid it.
493 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint>;
495 // Convenient helper methods based on the above methods
497 /// Reads at least `min` bytes and places them in `buf`.
498 /// Returns the number of bytes read.
500 /// This will continue to call `read` until at least `min` bytes have been
501 /// read. If `read` returns 0 too many times, `NoProgress` will be
506 /// If an error occurs at any point, that error is returned, and no further
508 fn read_at_least(&mut self, min: uint, buf: &mut [u8]) -> IoResult<uint> {
511 detail: Some(String::from_str("the buffer is too short")),
512 ..standard_error(InvalidInput)
519 match self.read(buf.slice_from_mut(read)) {
522 if zeroes >= NO_PROGRESS_LIMIT {
523 return Err(standard_error(NoProgress));
530 err@Err(_) => return err
537 /// Reads a single byte. Returns `Err` on EOF.
538 fn read_byte(&mut self) -> IoResult<u8> {
540 try!(self.read_at_least(1, &mut buf));
544 /// Reads up to `len` bytes and appends them to a vector.
545 /// Returns the number of bytes read. The number of bytes read may be
546 /// less than the number requested, even 0. Returns Err on EOF.
550 /// If an error occurs during this I/O operation, then it is returned
551 /// as `Err(IoError)`. See `read()` for more details.
552 fn push(&mut self, len: uint, buf: &mut Vec<u8>) -> IoResult<uint> {
553 let start_len = buf.len();
557 let s = unsafe { slice_vec_capacity(buf, start_len, start_len + len) };
560 unsafe { buf.set_len(start_len + n) };
564 /// Reads at least `min` bytes, but no more than `len`, and appends them to
566 /// Returns the number of bytes read.
568 /// This will continue to call `read` until at least `min` bytes have been
569 /// read. If `read` returns 0 too many times, `NoProgress` will be
574 /// If an error occurs at any point, that error is returned, and no further
576 fn push_at_least(&mut self, min: uint, len: uint, buf: &mut Vec<u8>) -> IoResult<uint> {
579 detail: Some(String::from_str("the buffer is too short")),
580 ..standard_error(InvalidInput)
584 let start_len = buf.len();
587 // we can't just use self.read_at_least(min, slice) because we need to push
588 // successful reads onto the vector before any returned errors.
593 let s = unsafe { slice_vec_capacity(buf, start_len + read, start_len + len) };
594 try!(self.read_at_least(1, s))
596 unsafe { buf.set_len(start_len + read) };
601 /// Reads exactly `len` bytes and gives you back a new vector of length
606 /// Fails with the same conditions as `read`. Additionally returns error
607 /// on EOF. Note that if an error is returned, then some number of bytes may
608 /// have already been consumed from the underlying reader, and they are lost
609 /// (not returned as part of the error). If this is unacceptable, then it is
610 /// recommended to use the `push_at_least` or `read` methods.
611 fn read_exact(&mut self, len: uint) -> IoResult<Vec<u8>> {
612 let mut buf = Vec::with_capacity(len);
613 match self.push_at_least(len, len, &mut buf) {
619 /// Reads all remaining bytes from the stream.
623 /// Returns any non-EOF error immediately. Previously read bytes are
624 /// discarded when an error is returned.
626 /// When EOF is encountered, all bytes read up to that point are returned.
627 fn read_to_end(&mut self) -> IoResult<Vec<u8>> {
628 let mut buf = Vec::with_capacity(DEFAULT_BUF_SIZE);
630 match self.push_at_least(1, DEFAULT_BUF_SIZE, &mut buf) {
632 Err(ref e) if e.kind == EndOfFile => break,
633 Err(e) => return Err(e)
639 /// Reads all of the remaining bytes of this stream, interpreting them as a
640 /// UTF-8 encoded stream. The corresponding string is returned.
644 /// This function returns all of the same errors as `read_to_end` with an
645 /// additional error if the reader's contents are not a valid sequence of
647 fn read_to_string(&mut self) -> IoResult<String> {
648 self.read_to_end().and_then(|s| {
649 match String::from_utf8(s) {
651 Err(_) => Err(standard_error(InvalidInput)),
656 // Byte conversion helpers
658 /// Reads `n` little-endian unsigned integer bytes.
660 /// `n` must be between 1 and 8, inclusive.
661 fn read_le_uint_n(&mut self, nbytes: uint) -> IoResult<u64> {
662 assert!(nbytes > 0 && nbytes <= 8);
668 val += (try!(self.read_u8()) as u64) << pos;
675 /// Reads `n` little-endian signed integer bytes.
677 /// `n` must be between 1 and 8, inclusive.
678 fn read_le_int_n(&mut self, nbytes: uint) -> IoResult<i64> {
679 self.read_le_uint_n(nbytes).map(|i| extend_sign(i, nbytes))
682 /// Reads `n` big-endian unsigned integer bytes.
684 /// `n` must be between 1 and 8, inclusive.
685 fn read_be_uint_n(&mut self, nbytes: uint) -> IoResult<u64> {
686 assert!(nbytes > 0 && nbytes <= 8);
692 val += (try!(self.read_u8()) as u64) << i * 8;
697 /// Reads `n` big-endian signed integer bytes.
699 /// `n` must be between 1 and 8, inclusive.
700 fn read_be_int_n(&mut self, nbytes: uint) -> IoResult<i64> {
701 self.read_be_uint_n(nbytes).map(|i| extend_sign(i, nbytes))
704 /// Reads a little-endian unsigned integer.
706 /// The number of bytes returned is system-dependent.
707 fn read_le_uint(&mut self) -> IoResult<uint> {
708 self.read_le_uint_n(uint::BYTES).map(|i| i as uint)
711 /// Reads a little-endian integer.
713 /// The number of bytes returned is system-dependent.
714 fn read_le_int(&mut self) -> IoResult<int> {
715 self.read_le_int_n(int::BYTES).map(|i| i as int)
718 /// Reads a big-endian unsigned integer.
720 /// The number of bytes returned is system-dependent.
721 fn read_be_uint(&mut self) -> IoResult<uint> {
722 self.read_be_uint_n(uint::BYTES).map(|i| i as uint)
725 /// Reads a big-endian integer.
727 /// The number of bytes returned is system-dependent.
728 fn read_be_int(&mut self) -> IoResult<int> {
729 self.read_be_int_n(int::BYTES).map(|i| i as int)
732 /// Reads a big-endian `u64`.
734 /// `u64`s are 8 bytes long.
735 fn read_be_u64(&mut self) -> IoResult<u64> {
736 self.read_be_uint_n(8)
739 /// Reads a big-endian `u32`.
741 /// `u32`s are 4 bytes long.
742 fn read_be_u32(&mut self) -> IoResult<u32> {
743 self.read_be_uint_n(4).map(|i| i as u32)
746 /// Reads a big-endian `u16`.
748 /// `u16`s are 2 bytes long.
749 fn read_be_u16(&mut self) -> IoResult<u16> {
750 self.read_be_uint_n(2).map(|i| i as u16)
753 /// Reads a big-endian `i64`.
755 /// `i64`s are 8 bytes long.
756 fn read_be_i64(&mut self) -> IoResult<i64> {
757 self.read_be_int_n(8)
760 /// Reads a big-endian `i32`.
762 /// `i32`s are 4 bytes long.
763 fn read_be_i32(&mut self) -> IoResult<i32> {
764 self.read_be_int_n(4).map(|i| i as i32)
767 /// Reads a big-endian `i16`.
769 /// `i16`s are 2 bytes long.
770 fn read_be_i16(&mut self) -> IoResult<i16> {
771 self.read_be_int_n(2).map(|i| i as i16)
774 /// Reads a big-endian `f64`.
776 /// `f64`s are 8 byte, IEEE754 double-precision floating point numbers.
777 fn read_be_f64(&mut self) -> IoResult<f64> {
778 self.read_be_u64().map(|i| unsafe {
779 transmute::<u64, f64>(i)
783 /// Reads a big-endian `f32`.
785 /// `f32`s are 4 byte, IEEE754 single-precision floating point numbers.
786 fn read_be_f32(&mut self) -> IoResult<f32> {
787 self.read_be_u32().map(|i| unsafe {
788 transmute::<u32, f32>(i)
792 /// Reads a little-endian `u64`.
794 /// `u64`s are 8 bytes long.
795 fn read_le_u64(&mut self) -> IoResult<u64> {
796 self.read_le_uint_n(8)
799 /// Reads a little-endian `u32`.
801 /// `u32`s are 4 bytes long.
802 fn read_le_u32(&mut self) -> IoResult<u32> {
803 self.read_le_uint_n(4).map(|i| i as u32)
806 /// Reads a little-endian `u16`.
808 /// `u16`s are 2 bytes long.
809 fn read_le_u16(&mut self) -> IoResult<u16> {
810 self.read_le_uint_n(2).map(|i| i as u16)
813 /// Reads a little-endian `i64`.
815 /// `i64`s are 8 bytes long.
816 fn read_le_i64(&mut self) -> IoResult<i64> {
817 self.read_le_int_n(8)
820 /// Reads a little-endian `i32`.
822 /// `i32`s are 4 bytes long.
823 fn read_le_i32(&mut self) -> IoResult<i32> {
824 self.read_le_int_n(4).map(|i| i as i32)
827 /// Reads a little-endian `i16`.
829 /// `i16`s are 2 bytes long.
830 fn read_le_i16(&mut self) -> IoResult<i16> {
831 self.read_le_int_n(2).map(|i| i as i16)
834 /// Reads a little-endian `f64`.
836 /// `f64`s are 8 byte, IEEE754 double-precision floating point numbers.
837 fn read_le_f64(&mut self) -> IoResult<f64> {
838 self.read_le_u64().map(|i| unsafe {
839 transmute::<u64, f64>(i)
843 /// Reads a little-endian `f32`.
845 /// `f32`s are 4 byte, IEEE754 single-precision floating point numbers.
846 fn read_le_f32(&mut self) -> IoResult<f32> {
847 self.read_le_u32().map(|i| unsafe {
848 transmute::<u32, f32>(i)
854 /// `u8`s are 1 byte.
855 fn read_u8(&mut self) -> IoResult<u8> {
861 /// `i8`s are 1 byte.
862 fn read_i8(&mut self) -> IoResult<i8> {
863 self.read_byte().map(|i| i as i8)
867 /// A reader which can be converted to a RefReader.
868 pub trait ByRefReader {
869 /// Creates a wrapper around a mutable reference to the reader.
871 /// This is useful to allow applying adaptors while still
872 /// retaining ownership of the original value.
873 fn by_ref<'a>(&'a mut self) -> RefReader<'a, Self>;
876 impl<T: Reader> ByRefReader for T {
877 fn by_ref<'a>(&'a mut self) -> RefReader<'a, T> {
878 RefReader { inner: self }
882 /// A reader which can be converted to bytes.
883 pub trait BytesReader {
884 /// Create an iterator that reads a single byte on
885 /// each iteration, until EOF.
889 /// Any error other than `EndOfFile` that is produced by the underlying Reader
890 /// is returned by the iterator and should be handled by the caller.
891 fn bytes<'r>(&'r mut self) -> extensions::Bytes<'r, Self>;
894 impl<T: Reader> BytesReader for T {
895 fn bytes<'r>(&'r mut self) -> extensions::Bytes<'r, T> {
896 extensions::Bytes::new(self)
900 impl<'a> Reader for Box<Reader+'a> {
901 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> {
902 let reader: &mut Reader = &mut **self;
907 impl<'a> Reader for &'a mut (Reader+'a) {
908 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> { (*self).read(buf) }
911 /// Returns a slice of `v` between `start` and `end`.
913 /// Similar to `slice()` except this function only bounds the slice on the
914 /// capacity of `v`, not the length.
918 /// Panics when `start` or `end` point outside the capacity of `v`, or when
920 // Private function here because we aren't sure if we want to expose this as
921 // API yet. If so, it should be a method on Vec.
922 unsafe fn slice_vec_capacity<'a, T>(v: &'a mut Vec<T>, start: uint, end: uint) -> &'a mut [T] {
926 assert!(start <= end);
927 assert!(end <= v.capacity());
929 data: v.as_ptr().offset(start as int),
934 /// A `RefReader` is a struct implementing `Reader` which contains a reference
935 /// to another reader. This is often useful when composing streams.
941 /// # fn process_input<R: Reader>(r: R) {}
944 /// use std::io::ByRefReader;
945 /// use std::io::util::LimitReader;
947 /// let mut stream = io::stdin();
949 /// // Only allow the function to process at most one kilobyte of input
951 /// let stream = LimitReader::new(stream.by_ref(), 1024);
952 /// process_input(stream);
955 /// // 'stream' is still available for use here
959 pub struct RefReader<'a, R:'a> {
960 /// The underlying reader which this is referencing
964 impl<'a, R: Reader> Reader for RefReader<'a, R> {
965 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> { self.inner.read(buf) }
968 impl<'a, R: Buffer> Buffer for RefReader<'a, R> {
969 fn fill_buf(&mut self) -> IoResult<&[u8]> { self.inner.fill_buf() }
970 fn consume(&mut self, amt: uint) { self.inner.consume(amt) }
973 fn extend_sign(val: u64, nbytes: uint) -> i64 {
974 let shift = (8 - nbytes) * 8;
975 (val << shift) as i64 >> shift
978 /// A trait for objects which are byte-oriented streams. Writers are defined by
979 /// one method, `write`. This function will block until the provided buffer of
980 /// bytes has been entirely written, and it will return any failures which occur.
982 /// Another commonly overridden method is the `flush` method for writers such as
983 /// buffered writers.
985 /// Writers are intended to be composable with one another. Many objects
986 /// throughout the I/O and related libraries take and provide types which
987 /// implement the `Writer` trait.
989 /// Write the entirety of a given buffer
993 /// If an error happens during the I/O operation, the error is returned as
994 /// `Err`. Note that it is considered an error if the entire buffer could
995 /// not be written, and if an error is returned then it is unknown how much
996 /// data (if any) was actually written.
997 fn write(&mut self, buf: &[u8]) -> IoResult<()>;
999 /// Flush this output stream, ensuring that all intermediately buffered
1000 /// contents reach their destination.
1002 /// This is by default a no-op and implementers of the `Writer` trait should
1003 /// decide whether their stream needs to be buffered or not.
1004 fn flush(&mut self) -> IoResult<()> { Ok(()) }
1006 /// Writes a formatted string into this writer, returning any error
1009 /// This method is primarily used to interface with the `format_args!`
1010 /// macro, but it is rare that this should explicitly be called. The
1011 /// `write!` macro should be favored to invoke this method instead.
1015 /// This function will return any I/O error reported while formatting.
1016 fn write_fmt(&mut self, fmt: fmt::Arguments) -> IoResult<()> {
1017 // Create a shim which translates a Writer to a fmt::Writer and saves
1018 // off I/O errors. instead of discarding them
1019 struct Adaptor<'a, T: ?Sized +'a> {
1021 error: IoResult<()>,
1024 impl<'a, T: ?Sized + Writer> fmt::Writer for Adaptor<'a, T> {
1025 fn write_str(&mut self, s: &str) -> fmt::Result {
1026 match self.inner.write(s.as_bytes()) {
1029 self.error = Err(e);
1036 let mut output = Adaptor { inner: self, error: Ok(()) };
1037 match fmt::write(&mut output, fmt) {
1039 Err(..) => output.error
1044 /// Write a rust string into this sink.
1046 /// The bytes written will be the UTF-8 encoded version of the input string.
1047 /// If other encodings are desired, it is recommended to compose this stream
1048 /// with another performing the conversion, or to use `write` with a
1049 /// converted byte-array instead.
1051 fn write_str(&mut self, s: &str) -> IoResult<()> {
1052 self.write(s.as_bytes())
1055 /// Writes a string into this sink, and then writes a literal newline (`\n`)
1056 /// byte afterwards. Note that the writing of the newline is *not* atomic in
1057 /// the sense that the call to `write` is invoked twice (once with the
1058 /// string and once with a newline character).
1060 /// If other encodings or line ending flavors are desired, it is recommended
1061 /// that the `write` method is used specifically instead.
1063 fn write_line(&mut self, s: &str) -> IoResult<()> {
1064 self.write_str(s).and_then(|()| self.write(&[b'\n']))
1067 /// Write a single char, encoded as UTF-8.
1069 fn write_char(&mut self, c: char) -> IoResult<()> {
1070 let mut buf = [0u8; 4];
1071 let n = c.encode_utf8(buf.as_mut_slice()).unwrap_or(0);
1072 self.write(&buf[0..n])
1075 /// Write the result of passing n through `int::to_str_bytes`.
1077 fn write_int(&mut self, n: int) -> IoResult<()> {
1078 write!(self, "{}", n)
1081 /// Write the result of passing n through `uint::to_str_bytes`.
1083 fn write_uint(&mut self, n: uint) -> IoResult<()> {
1084 write!(self, "{}", n)
1087 /// Write a little-endian uint (number of bytes depends on system).
1089 fn write_le_uint(&mut self, n: uint) -> IoResult<()> {
1090 extensions::u64_to_le_bytes(n as u64, uint::BYTES, |v| self.write(v))
1093 /// Write a little-endian int (number of bytes depends on system).
1095 fn write_le_int(&mut self, n: int) -> IoResult<()> {
1096 extensions::u64_to_le_bytes(n as u64, int::BYTES, |v| self.write(v))
1099 /// Write a big-endian uint (number of bytes depends on system).
1101 fn write_be_uint(&mut self, n: uint) -> IoResult<()> {
1102 extensions::u64_to_be_bytes(n as u64, uint::BYTES, |v| self.write(v))
1105 /// Write a big-endian int (number of bytes depends on system).
1107 fn write_be_int(&mut self, n: int) -> IoResult<()> {
1108 extensions::u64_to_be_bytes(n as u64, int::BYTES, |v| self.write(v))
1111 /// Write a big-endian u64 (8 bytes).
1113 fn write_be_u64(&mut self, n: u64) -> IoResult<()> {
1114 extensions::u64_to_be_bytes(n, 8u, |v| self.write(v))
1117 /// Write a big-endian u32 (4 bytes).
1119 fn write_be_u32(&mut self, n: u32) -> IoResult<()> {
1120 extensions::u64_to_be_bytes(n as u64, 4u, |v| self.write(v))
1123 /// Write a big-endian u16 (2 bytes).
1125 fn write_be_u16(&mut self, n: u16) -> IoResult<()> {
1126 extensions::u64_to_be_bytes(n as u64, 2u, |v| self.write(v))
1129 /// Write a big-endian i64 (8 bytes).
1131 fn write_be_i64(&mut self, n: i64) -> IoResult<()> {
1132 extensions::u64_to_be_bytes(n as u64, 8u, |v| self.write(v))
1135 /// Write a big-endian i32 (4 bytes).
1137 fn write_be_i32(&mut self, n: i32) -> IoResult<()> {
1138 extensions::u64_to_be_bytes(n as u64, 4u, |v| self.write(v))
1141 /// Write a big-endian i16 (2 bytes).
1143 fn write_be_i16(&mut self, n: i16) -> IoResult<()> {
1144 extensions::u64_to_be_bytes(n as u64, 2u, |v| self.write(v))
1147 /// Write a big-endian IEEE754 double-precision floating-point (8 bytes).
1149 fn write_be_f64(&mut self, f: f64) -> IoResult<()> {
1151 self.write_be_u64(transmute(f))
1155 /// Write a big-endian IEEE754 single-precision floating-point (4 bytes).
1157 fn write_be_f32(&mut self, f: f32) -> IoResult<()> {
1159 self.write_be_u32(transmute(f))
1163 /// Write a little-endian u64 (8 bytes).
1165 fn write_le_u64(&mut self, n: u64) -> IoResult<()> {
1166 extensions::u64_to_le_bytes(n, 8u, |v| self.write(v))
1169 /// Write a little-endian u32 (4 bytes).
1171 fn write_le_u32(&mut self, n: u32) -> IoResult<()> {
1172 extensions::u64_to_le_bytes(n as u64, 4u, |v| self.write(v))
1175 /// Write a little-endian u16 (2 bytes).
1177 fn write_le_u16(&mut self, n: u16) -> IoResult<()> {
1178 extensions::u64_to_le_bytes(n as u64, 2u, |v| self.write(v))
1181 /// Write a little-endian i64 (8 bytes).
1183 fn write_le_i64(&mut self, n: i64) -> IoResult<()> {
1184 extensions::u64_to_le_bytes(n as u64, 8u, |v| self.write(v))
1187 /// Write a little-endian i32 (4 bytes).
1189 fn write_le_i32(&mut self, n: i32) -> IoResult<()> {
1190 extensions::u64_to_le_bytes(n as u64, 4u, |v| self.write(v))
1193 /// Write a little-endian i16 (2 bytes).
1195 fn write_le_i16(&mut self, n: i16) -> IoResult<()> {
1196 extensions::u64_to_le_bytes(n as u64, 2u, |v| self.write(v))
1199 /// Write a little-endian IEEE754 double-precision floating-point
1202 fn write_le_f64(&mut self, f: f64) -> IoResult<()> {
1204 self.write_le_u64(transmute(f))
1208 /// Write a little-endian IEEE754 single-precision floating-point
1211 fn write_le_f32(&mut self, f: f32) -> IoResult<()> {
1213 self.write_le_u32(transmute(f))
1217 /// Write a u8 (1 byte).
1219 fn write_u8(&mut self, n: u8) -> IoResult<()> {
1223 /// Write an i8 (1 byte).
1225 fn write_i8(&mut self, n: i8) -> IoResult<()> {
1226 self.write(&[n as u8])
1230 /// A writer which can be converted to a RefWriter.
1231 pub trait ByRefWriter {
1232 /// Creates a wrapper around a mutable reference to the writer.
1234 /// This is useful to allow applying wrappers while still
1235 /// retaining ownership of the original value.
1237 fn by_ref<'a>(&'a mut self) -> RefWriter<'a, Self>;
1240 impl<T: Writer> ByRefWriter for T {
1241 fn by_ref<'a>(&'a mut self) -> RefWriter<'a, T> {
1242 RefWriter { inner: self }
1246 impl<'a> Writer for Box<Writer+'a> {
1248 fn write(&mut self, buf: &[u8]) -> IoResult<()> {
1249 (&mut **self).write(buf)
1253 fn flush(&mut self) -> IoResult<()> {
1254 (&mut **self).flush()
1258 impl<'a> Writer for &'a mut (Writer+'a) {
1260 fn write(&mut self, buf: &[u8]) -> IoResult<()> { (**self).write(buf) }
1263 fn flush(&mut self) -> IoResult<()> { (**self).flush() }
1266 /// A `RefWriter` is a struct implementing `Writer` which contains a reference
1267 /// to another writer. This is often useful when composing streams.
1273 /// # fn process_input<R: Reader>(r: R) {}
1275 /// use std::io::util::TeeReader;
1276 /// use std::io::{stdin, ByRefWriter};
1278 /// let mut output = Vec::new();
1281 /// // Don't give ownership of 'output' to the 'tee'. Instead we keep a
1282 /// // handle to it in the outer scope
1283 /// let mut tee = TeeReader::new(stdin(), output.by_ref());
1284 /// process_input(tee);
1287 /// println!("input processed: {:?}", output);
1290 pub struct RefWriter<'a, W:'a> {
1291 /// The underlying writer which this is referencing
1295 impl<'a, W: Writer> Writer for RefWriter<'a, W> {
1297 fn write(&mut self, buf: &[u8]) -> IoResult<()> { self.inner.write(buf) }
1300 fn flush(&mut self) -> IoResult<()> { self.inner.flush() }
1304 /// A Stream is a readable and a writable object. Data written is typically
1305 /// received by the object which reads receive data from.
1306 pub trait Stream: Reader + Writer { }
1308 impl<T: Reader + Writer> Stream for T {}
1310 /// An iterator that reads a line on each iteration,
1311 /// until `.read_line()` encounters `EndOfFile`.
1313 /// # Notes about the Iteration Protocol
1315 /// The `Lines` may yield `None` and thus terminate
1316 /// an iteration, but continue to yield elements if iteration
1317 /// is attempted again.
1321 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1322 /// is returned by the iterator and should be handled by the caller.
1323 pub struct Lines<'r, T:'r> {
1327 impl<'r, T: Buffer> Iterator for Lines<'r, T> {
1328 type Item = IoResult<String>;
1330 fn next(&mut self) -> Option<IoResult<String>> {
1331 match self.buffer.read_line() {
1332 Ok(x) => Some(Ok(x)),
1333 Err(IoError { kind: EndOfFile, ..}) => None,
1334 Err(y) => Some(Err(y))
1339 /// An iterator that reads a utf8-encoded character on each iteration,
1340 /// until `.read_char()` encounters `EndOfFile`.
1342 /// # Notes about the Iteration Protocol
1344 /// The `Chars` may yield `None` and thus terminate
1345 /// an iteration, but continue to yield elements if iteration
1346 /// is attempted again.
1350 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1351 /// is returned by the iterator and should be handled by the caller.
1352 pub struct Chars<'r, T:'r> {
1356 impl<'r, T: Buffer> Iterator for Chars<'r, T> {
1357 type Item = IoResult<char>;
1359 fn next(&mut self) -> Option<IoResult<char>> {
1360 match self.buffer.read_char() {
1361 Ok(x) => Some(Ok(x)),
1362 Err(IoError { kind: EndOfFile, ..}) => None,
1363 Err(y) => Some(Err(y))
1368 /// A Buffer is a type of reader which has some form of internal buffering to
1369 /// allow certain kinds of reading operations to be more optimized than others.
1370 /// This type extends the `Reader` trait with a few methods that are not
1371 /// possible to reasonably implement with purely a read interface.
1372 pub trait Buffer: Reader {
1373 /// Fills the internal buffer of this object, returning the buffer contents.
1374 /// Note that none of the contents will be "read" in the sense that later
1375 /// calling `read` may return the same contents.
1377 /// The `consume` function must be called with the number of bytes that are
1378 /// consumed from this buffer returned to ensure that the bytes are never
1383 /// This function will return an I/O error if the underlying reader was
1384 /// read, but returned an error. Note that it is not an error to return a
1385 /// 0-length buffer.
1386 fn fill_buf<'a>(&'a mut self) -> IoResult<&'a [u8]>;
1388 /// Tells this buffer that `amt` bytes have been consumed from the buffer,
1389 /// so they should no longer be returned in calls to `read`.
1390 fn consume(&mut self, amt: uint);
1392 /// Reads the next line of input, interpreted as a sequence of UTF-8
1393 /// encoded Unicode codepoints. If a newline is encountered, then the
1394 /// newline is contained in the returned string.
1399 /// use std::io::BufReader;
1401 /// let mut reader = BufReader::new(b"hello\nworld");
1402 /// assert_eq!("hello\n", &*reader.read_line().unwrap());
1407 /// This function has the same error semantics as `read_until`:
1409 /// * All non-EOF errors will be returned immediately
1410 /// * If an error is returned previously consumed bytes are lost
1411 /// * EOF is only returned if no bytes have been read
1412 /// * Reach EOF may mean that the delimiter is not present in the return
1415 /// Additionally, this function can fail if the line of input read is not a
1416 /// valid UTF-8 sequence of bytes.
1417 fn read_line(&mut self) -> IoResult<String> {
1418 self.read_until(b'\n').and_then(|line|
1419 match String::from_utf8(line) {
1421 Err(_) => Err(standard_error(InvalidInput)),
1426 /// Reads a sequence of bytes leading up to a specified delimiter. Once the
1427 /// specified byte is encountered, reading ceases and the bytes up to and
1428 /// including the delimiter are returned.
1432 /// If any I/O error is encountered other than EOF, the error is immediately
1433 /// returned. Note that this may discard bytes which have already been read,
1434 /// and those bytes will *not* be returned. It is recommended to use other
1435 /// methods if this case is worrying.
1437 /// If EOF is encountered, then this function will return EOF if 0 bytes
1438 /// have been read, otherwise the pending byte buffer is returned. This
1439 /// is the reason that the byte buffer returned may not always contain the
1441 fn read_until(&mut self, byte: u8) -> IoResult<Vec<u8>> {
1442 let mut res = Vec::new();
1447 let available = match self.fill_buf() {
1449 Err(ref e) if res.len() > 0 && e.kind == EndOfFile => {
1453 Err(e) => return Err(e)
1455 match available.iter().position(|&b| b == byte) {
1457 res.push_all(&available[0..(i + 1)]);
1462 res.push_all(available);
1463 used = available.len();
1473 /// Reads the next utf8-encoded character from the underlying stream.
1477 /// If an I/O error occurs, or EOF, then this function will return `Err`.
1478 /// This function will also return error if the stream does not contain a
1479 /// valid utf-8 encoded codepoint as the next few bytes in the stream.
1480 fn read_char(&mut self) -> IoResult<char> {
1481 let first_byte = try!(self.read_byte());
1482 let width = unicode::str::utf8_char_width(first_byte);
1483 if width == 1 { return Ok(first_byte as char) }
1484 if width == 0 { return Err(standard_error(InvalidInput)) } // not utf8
1485 let mut buf = [first_byte, 0, 0, 0];
1488 while start < width {
1489 match try!(self.read(buf.slice_mut(start, width))) {
1490 n if n == width - start => break,
1491 n if n < width - start => { start += n; }
1492 _ => return Err(standard_error(InvalidInput)),
1496 match str::from_utf8(&buf[0..width]).ok() {
1497 Some(s) => Ok(s.char_at(0)),
1498 None => Err(standard_error(InvalidInput))
1503 /// Extension methods for the Buffer trait which are included in the prelude.
1504 pub trait BufferPrelude {
1505 /// Create an iterator that reads a utf8-encoded character on each iteration
1510 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1511 /// is returned by the iterator and should be handled by the caller.
1512 fn chars<'r>(&'r mut self) -> Chars<'r, Self>;
1514 /// Create an iterator that reads a line on each iteration until EOF.
1518 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1519 /// is returned by the iterator and should be handled by the caller.
1520 fn lines<'r>(&'r mut self) -> Lines<'r, Self>;
1523 impl<T: Buffer> BufferPrelude for T {
1524 fn chars<'r>(&'r mut self) -> Chars<'r, T> {
1525 Chars { buffer: self }
1528 fn lines<'r>(&'r mut self) -> Lines<'r, T> {
1529 Lines { buffer: self }
1533 /// When seeking, the resulting cursor is offset from a base by the offset given
1534 /// to the `seek` function. The base used is specified by this enumeration.
1536 pub enum SeekStyle {
1537 /// Seek from the beginning of the stream
1539 /// Seek from the end of the stream
1541 /// Seek from the current position
1545 /// An object implementing `Seek` internally has some form of cursor which can
1546 /// be moved within a stream of bytes. The stream typically has a fixed size,
1547 /// allowing seeking relative to either end.
1549 /// Return position of file cursor in the stream
1550 fn tell(&self) -> IoResult<u64>;
1552 /// Seek to an offset in a stream
1554 /// A successful seek clears the EOF indicator. Seeking beyond EOF is
1555 /// allowed, but seeking before position 0 is not allowed.
1559 /// * Seeking to a negative offset is considered an error
1560 /// * Seeking past the end of the stream does not modify the underlying
1561 /// stream, but the next write may cause the previous data to be filled in
1562 /// with a bit pattern.
1563 fn seek(&mut self, pos: i64, style: SeekStyle) -> IoResult<()>;
1566 /// A listener is a value that can consume itself to start listening for
1569 /// Doing so produces some sort of Acceptor.
1570 pub trait Listener<T, A: Acceptor<T>> {
1571 /// Spin up the listener and start queuing incoming connections
1575 /// Returns `Err` if this listener could not be bound to listen for
1576 /// connections. In all cases, this listener is consumed.
1577 fn listen(self) -> IoResult<A>;
1580 /// An acceptor is a value that presents incoming connections
1581 pub trait Acceptor<T> {
1582 /// Wait for and accept an incoming connection
1586 /// Returns `Err` if an I/O error is encountered.
1587 fn accept(&mut self) -> IoResult<T>;
1589 /// Create an iterator over incoming connection attempts.
1591 /// Note that I/O errors will be yielded by the iterator itself.
1592 fn incoming<'r>(&'r mut self) -> IncomingConnections<'r, Self> {
1593 IncomingConnections { inc: self }
1597 /// An infinite iterator over incoming connection attempts.
1598 /// Calling `next` will block the task until a connection is attempted.
1600 /// Since connection attempts can continue forever, this iterator always returns
1601 /// `Some`. The `Some` contains the `IoResult` representing whether the
1602 /// connection attempt was successful. A successful connection will be wrapped
1603 /// in `Ok`. A failed connection is represented as an `Err`.
1604 pub struct IncomingConnections<'a, A: ?Sized +'a> {
1609 impl<'a, T, A: ?Sized + Acceptor<T>> Iterator for IncomingConnections<'a, A> {
1610 type Item = IoResult<T>;
1612 fn next(&mut self) -> Option<IoResult<T>> {
1613 Some(self.inc.accept())
1617 /// Creates a standard error for a commonly used flavor of error. The `detail`
1618 /// field of the returned error will always be `None`.
1625 /// let eof = io::standard_error(io::EndOfFile);
1626 /// let einval = io::standard_error(io::InvalidInput);
1628 pub fn standard_error(kind: IoErrorKind) -> IoError {
1629 let desc = match kind {
1630 EndOfFile => "end of file",
1631 IoUnavailable => "I/O is unavailable",
1632 InvalidInput => "invalid input",
1633 OtherIoError => "unknown I/O error",
1634 FileNotFound => "file not found",
1635 PermissionDenied => "permission denied",
1636 ConnectionFailed => "connection failed",
1637 Closed => "stream is closed",
1638 ConnectionRefused => "connection refused",
1639 ConnectionReset => "connection reset",
1640 ConnectionAborted => "connection aborted",
1641 NotConnected => "not connected",
1642 BrokenPipe => "broken pipe",
1643 PathAlreadyExists => "file already exists",
1644 PathDoesntExist => "no such file",
1645 MismatchedFileTypeForOperation => "mismatched file type",
1646 ResourceUnavailable => "resource unavailable",
1647 TimedOut => "operation timed out",
1648 ShortWrite(..) => "short write",
1649 NoProgress => "no progress",
1658 /// A mode specifies how a file should be opened or created. These modes are
1659 /// passed to `File::open_mode` and are used to control where the file is
1660 /// positioned when it is initially opened.
1661 #[derive(Copy, Clone, PartialEq, Eq, Show)]
1663 /// Opens a file positioned at the beginning.
1665 /// Opens a file positioned at EOF.
1667 /// Opens a file, truncating it if it already exists.
1671 /// Access permissions with which the file should be opened. `File`s
1672 /// opened with `Read` will return an error if written to.
1673 #[derive(Copy, Clone, PartialEq, Eq, Show)]
1674 pub enum FileAccess {
1675 /// Read-only access, requests to write will result in an error
1677 /// Write-only access, requests to read will result in an error
1679 /// Read-write access, no requests are denied by default
1683 /// Different kinds of files which can be identified by a call to stat
1684 #[derive(Copy, PartialEq, Show, Hash, Clone)]
1686 /// This is a normal file, corresponding to `S_IFREG`
1689 /// This file is a directory, corresponding to `S_IFDIR`
1692 /// This file is a named pipe, corresponding to `S_IFIFO`
1695 /// This file is a block device, corresponding to `S_IFBLK`
1698 /// This file is a symbolic link to another file, corresponding to `S_IFLNK`
1701 /// The type of this file is not recognized as one of the other categories
1705 /// A structure used to describe metadata information about a file. This
1706 /// structure is created through the `stat` method on a `Path`.
1711 /// # use std::io::fs::PathExtensions;
1714 /// let info = match Path::new("foo.txt").stat() {
1715 /// Ok(stat) => stat,
1716 /// Err(e) => panic!("couldn't read foo.txt: {}", e),
1719 /// println!("byte size: {}", info.size);
1722 #[derive(Copy, Hash)]
1723 pub struct FileStat {
1724 /// The size of the file, in bytes
1726 /// The kind of file this path points to (directory, file, pipe, etc.)
1728 /// The file permissions currently on the file
1729 pub perm: FilePermission,
1731 // FIXME(#10301): These time fields are pretty useless without an actual
1732 // time representation, what are the milliseconds relative
1735 /// The time that the file was created at, in platform-dependent
1738 /// The time that this file was last modified, in platform-dependent
1741 /// The time that this file was last accessed, in platform-dependent
1745 /// Information returned by stat() which is not guaranteed to be
1746 /// platform-independent. This information may be useful on some platforms,
1747 /// but it may have different meanings or no meaning at all on other
1750 /// Usage of this field is discouraged, but if access is desired then the
1751 /// fields are located here.
1753 pub unstable: UnstableFileStat,
1756 /// This structure represents all of the possible information which can be
1757 /// returned from a `stat` syscall which is not contained in the `FileStat`
1758 /// structure. This information is not necessarily platform independent, and may
1759 /// have different meanings or no meaning at all on some platforms.
1761 #[derive(Copy, Hash)]
1762 pub struct UnstableFileStat {
1763 /// The ID of the device containing the file.
1765 /// The file serial number.
1769 /// The number of hard links to this file.
1771 /// The user ID of the file.
1773 /// The group ID of the file.
1775 /// The optimal block size for I/O.
1777 /// The blocks allocated for this file.
1779 /// User-defined flags for the file.
1781 /// The file generation number.
1787 /// A set of permissions for a file or directory is represented by a set of
1788 /// flags which are or'd together.
1789 flags FilePermission: u32 {
1790 const USER_READ = 0o400,
1791 const USER_WRITE = 0o200,
1792 const USER_EXECUTE = 0o100,
1793 const GROUP_READ = 0o040,
1794 const GROUP_WRITE = 0o020,
1795 const GROUP_EXECUTE = 0o010,
1796 const OTHER_READ = 0o004,
1797 const OTHER_WRITE = 0o002,
1798 const OTHER_EXECUTE = 0o001,
1800 const USER_RWX = USER_READ.bits | USER_WRITE.bits | USER_EXECUTE.bits,
1801 const GROUP_RWX = GROUP_READ.bits | GROUP_WRITE.bits | GROUP_EXECUTE.bits,
1802 const OTHER_RWX = OTHER_READ.bits | OTHER_WRITE.bits | OTHER_EXECUTE.bits,
1804 /// Permissions for user owned files, equivalent to 0644 on unix-like
1806 const USER_FILE = USER_READ.bits | USER_WRITE.bits | GROUP_READ.bits | OTHER_READ.bits,
1808 /// Permissions for user owned directories, equivalent to 0755 on
1809 /// unix-like systems.
1810 const USER_DIR = USER_RWX.bits | GROUP_READ.bits | GROUP_EXECUTE.bits |
1811 OTHER_READ.bits | OTHER_EXECUTE.bits,
1813 /// Permissions for user owned executables, equivalent to 0755
1814 /// on unix-like systems.
1815 const USER_EXEC = USER_DIR.bits,
1817 /// All possible permissions enabled.
1818 const ALL_PERMISSIONS = USER_RWX.bits | GROUP_RWX.bits | OTHER_RWX.bits,
1824 impl Default for FilePermission {
1827 fn default() -> FilePermission { FilePermission::empty() }
1830 impl fmt::Show for FilePermission {
1831 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1832 fmt::String::fmt(self, f)
1836 impl fmt::String for FilePermission {
1837 fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
1838 write!(f, "{:04o}", self.bits)
1844 use self::BadReaderBehavior::*;
1845 use super::{IoResult, Reader, MemReader, NoProgress, InvalidInput, Writer};
1846 use prelude::v1::{Ok, Vec, Buffer, SliceExt};
1849 #[derive(Clone, PartialEq, Show)]
1850 enum BadReaderBehavior {
1855 struct BadReader<T> {
1857 behavior: Vec<BadReaderBehavior>,
1860 impl<T: Reader> BadReader<T> {
1861 fn new(r: T, behavior: Vec<BadReaderBehavior>) -> BadReader<T> {
1862 BadReader { behavior: behavior, r: r }
1866 impl<T: Reader> Reader for BadReader<T> {
1867 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> {
1868 let BadReader { ref mut behavior, ref mut r } = *self;
1870 if behavior.is_empty() {
1871 // fall back on good
1874 match behavior.as_mut_slice()[0] {
1875 GoodBehavior(0) => (),
1876 GoodBehavior(ref mut x) => {
1880 BadBehavior(0) => (),
1881 BadBehavior(ref mut x) => {
1892 fn test_read_at_least() {
1893 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1894 vec![GoodBehavior(uint::MAX)]);
1895 let buf = &mut [0u8; 5];
1896 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1897 assert!(r.read_exact(5).unwrap().len() == 5); // read_exact uses read_at_least
1898 assert!(r.read_at_least(0, buf).is_ok());
1900 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1901 vec![BadBehavior(50), GoodBehavior(uint::MAX)]);
1902 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1904 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1905 vec![BadBehavior(1), GoodBehavior(1),
1906 BadBehavior(50), GoodBehavior(uint::MAX)]);
1907 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1908 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1910 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1911 vec![BadBehavior(uint::MAX)]);
1912 assert_eq!(r.read_at_least(1, buf).unwrap_err().kind, NoProgress);
1914 let mut r = MemReader::new(b"hello, world!".to_vec());
1915 assert_eq!(r.read_at_least(5, buf).unwrap(), 5);
1916 assert_eq!(r.read_at_least(6, buf).unwrap_err().kind, InvalidInput);
1920 fn test_push_at_least() {
1921 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1922 vec![GoodBehavior(uint::MAX)]);
1923 let mut buf = Vec::new();
1924 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1925 assert!(r.push_at_least(0, 5, &mut buf).is_ok());
1927 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1928 vec![BadBehavior(50), GoodBehavior(uint::MAX)]);
1929 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1931 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1932 vec![BadBehavior(1), GoodBehavior(1),
1933 BadBehavior(50), GoodBehavior(uint::MAX)]);
1934 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1935 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1937 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1938 vec![BadBehavior(uint::MAX)]);
1939 assert_eq!(r.push_at_least(1, 5, &mut buf).unwrap_err().kind, NoProgress);
1941 let mut r = MemReader::new(b"hello, world!".to_vec());
1942 assert_eq!(r.push_at_least(5, 1, &mut buf).unwrap_err().kind, InvalidInput);
1949 assert_eq!(format!("{}", USER_READ), "0400");
1950 assert_eq!(format!("{}", USER_FILE), "0644");
1951 assert_eq!(format!("{}", USER_EXEC), "0755");
1952 assert_eq!(format!("{}", USER_RWX), "0700");
1953 assert_eq!(format!("{}", GROUP_RWX), "0070");
1954 assert_eq!(format!("{}", OTHER_RWX), "0007");
1955 assert_eq!(format!("{}", ALL_PERMISSIONS), "0777");
1956 assert_eq!(format!("{}", USER_READ | USER_WRITE | OTHER_WRITE), "0602");
1959 fn _ensure_buffer_is_object_safe<T: Buffer>(x: &T) -> &Buffer {