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 // FIXME: cover these topics:
12 // path, reader, writer, stream, raii (close not needed),
13 // stdio, print!, println!, file access, process spawning,
17 /*! I/O, including files, networking, timers, and processes
19 `std::io` provides Rust's basic I/O types,
20 for reading and writing to files, TCP, UDP,
21 and other types of sockets and pipes,
22 manipulating the file system, spawning processes and signal handling.
26 Some examples of obvious things you might want to do
28 * Read lines from stdin
33 for line in io::stdin().lines() {
34 print!("{}", line.unwrap());
38 * Read a complete file
43 let contents = File::open(&Path::new("message.txt")).read_to_end();
46 * Write a line to a file
49 # #![allow(unused_must_use)]
52 let mut file = File::create(&Path::new("message.txt"));
53 file.write(b"hello, file!\n");
55 # ::std::io::fs::unlink(&Path::new("message.txt"));
58 * Iterate over the lines of a file
61 use std::io::BufferedReader;
64 let path = Path::new("message.txt");
65 let mut file = BufferedReader::new(File::open(&path));
66 for line in file.lines() {
67 print!("{}", line.unwrap());
71 * Pull the lines of a file into a vector of strings
74 use std::io::BufferedReader;
77 let path = Path::new("message.txt");
78 let mut file = BufferedReader::new(File::open(&path));
79 let lines: Vec<String> = file.lines().map(|x| x.unwrap()).collect();
82 * Make a simple TCP client connection and request
85 # #![allow(unused_must_use)]
86 use std::io::TcpStream;
88 # // connection doesn't fail if a server is running on 8080
89 # // locally, we still want to be type checking this code, so lets
90 # // just stop it running (#11576)
92 let mut socket = TcpStream::connect("127.0.0.1", 8080).unwrap();
93 socket.write(b"GET / HTTP/1.0\n\n");
94 let response = socket.read_to_end();
98 * Make a simple TCP server
103 # #![allow(dead_code)]
104 use std::io::{TcpListener, TcpStream};
105 use std::io::{Acceptor, Listener};
107 let listener = TcpListener::bind("127.0.0.1", 80);
109 // bind the listener to the specified address
110 let mut acceptor = listener.listen();
112 fn handle_client(mut stream: TcpStream) {
114 # &mut stream; // silence unused mutability/variable warning
116 // accept connections and process them, spawning a new tasks for each one
117 for stream in acceptor.incoming() {
119 Err(e) => { /* connection failed */ }
120 Ok(stream) => spawn(proc() {
121 // connection succeeded
122 handle_client(stream)
127 // close the socket server
135 I/O is an area where nearly every operation can result in unexpected
136 errors. Errors should be painfully visible when they happen, and handling them
137 should be easy to work with. It should be convenient to handle specific I/O
138 errors, and it should also be convenient to not deal with I/O errors.
140 Rust's I/O employs a combination of techniques to reduce boilerplate
141 while still providing feedback about errors. The basic strategy:
143 * All I/O operations return `IoResult<T>` which is equivalent to
144 `Result<T, IoError>`. The `Result` type is defined in the `std::result`
146 * If the `Result` type goes unused, then the compiler will by default emit a
147 warning about the unused result. This is because `Result` has the
148 `#[must_use]` attribute.
149 * Common traits are implemented for `IoResult`, e.g.
150 `impl<R: Reader> Reader for IoResult<R>`, so that error values do not have
151 to be 'unwrapped' before use.
153 These features combine in the API to allow for expressions like
154 `File::create(&Path::new("diary.txt")).write(b"Met a girl.\n")`
155 without having to worry about whether "diary.txt" exists or whether
156 the write succeeds. As written, if either `new` or `write_line`
157 encounters an error then the result of the entire expression will
160 If you wanted to handle the error though you might write:
163 # #![allow(unused_must_use)]
166 match File::create(&Path::new("diary.txt")).write(b"Met a girl.\n") {
167 Ok(()) => (), // succeeded
168 Err(e) => println!("failed to write to my diary: {}", e),
171 # ::std::io::fs::unlink(&Path::new("diary.txt"));
174 So what actually happens if `create` encounters an error?
175 It's important to know that what `new` returns is not a `File`
176 but an `IoResult<File>`. If the file does not open, then `new` will simply
177 return `Err(..)`. Because there is an implementation of `Writer` (the trait
178 required ultimately required for types to implement `write_line`) there is no
179 need to inspect or unwrap the `IoResult<File>` and we simply call `write_line`
180 on it. If `new` returned an `Err(..)` then the followup call to `write_line`
181 will also return an error.
185 Explicit pattern matching on `IoResult`s can get quite verbose, especially
186 when performing many I/O operations. Some examples (like those above) are
187 alleviated with extra methods implemented on `IoResult`, but others have more
188 complex interdependencies among each I/O operation.
190 The `try!` macro from `std::macros` is provided as a method of early-return
191 inside `Result`-returning functions. It expands to an early-return on `Err`
192 and otherwise unwraps the contained `Ok` value.
194 If you wanted to read several `u32`s from a file and return their product:
197 use std::io::{File, IoResult};
199 fn file_product(p: &Path) -> IoResult<u32> {
200 let mut f = File::open(p);
201 let x1 = try!(f.read_le_u32());
202 let x2 = try!(f.read_le_u32());
207 match file_product(&Path::new("numbers.bin")) {
208 Ok(x) => println!("{}", x),
209 Err(e) => println!("Failed to read numbers!")
213 With `try!` in `file_product`, each `read_le_u32` need not be directly
214 concerned with error handling; instead its caller is responsible for
215 responding to errors that may occur while attempting to read the numbers.
220 #![deny(unused_must_use)]
223 use collections::Collection;
229 use ops::{BitOr, BitAnd, Sub, Not};
230 use option::{Option, Some, None};
233 use result::{Ok, Err, Result};
235 use slice::{Vector, MutableVector, ImmutableVector};
236 use str::{Str, StrSlice};
243 pub use self::stdio::stdin;
244 pub use self::stdio::stdout;
245 pub use self::stdio::stderr;
246 pub use self::stdio::print;
247 pub use self::stdio::println;
249 pub use self::fs::File;
250 pub use self::timer::Timer;
251 pub use self::net::ip::IpAddr;
252 pub use self::net::tcp::TcpListener;
253 pub use self::net::tcp::TcpStream;
254 pub use self::net::udp::UdpStream;
255 pub use self::pipe::PipeStream;
256 pub use self::process::{Process, Command};
257 pub use self::tempfile::TempDir;
259 pub use self::mem::{MemReader, BufReader, MemWriter, BufWriter};
260 pub use self::buffered::{BufferedReader, BufferedWriter, BufferedStream,
262 pub use self::comm_adapters::{ChanReader, ChanWriter};
264 // this comes first to get the iotest! macro
282 /// The default buffer size for various I/O operations
283 // libuv recommends 64k buffers to maximize throughput
284 // https://groups.google.com/forum/#!topic/libuv/oQO1HJAIDdA
285 static DEFAULT_BUF_SIZE: uint = 1024 * 64;
287 /// A convenient typedef of the return value of any I/O action.
288 pub type IoResult<T> = Result<T, IoError>;
290 /// The type passed to I/O condition handlers to indicate error
294 /// Is something like this sufficient? It's kind of archaic
295 #[deriving(PartialEq, Clone)]
297 /// An enumeration which can be matched against for determining the flavor
299 pub kind: IoErrorKind,
300 /// A human-readable description about the error
301 pub desc: &'static str,
302 /// Detailed information about this error, not always available
303 pub detail: Option<String>
307 /// Convert an `errno` value into an `IoError`.
309 /// If `detail` is `true`, the `detail` field of the `IoError`
310 /// struct is filled with an allocated string describing the error
311 /// in more detail, retrieved from the operating system.
312 pub fn from_errno(errno: uint, detail: bool) -> IoError {
315 fn get_err(errno: i32) -> (IoErrorKind, &'static str) {
317 libc::EOF => (EndOfFile, "end of file"),
318 libc::ERROR_NO_DATA => (BrokenPipe, "the pipe is being closed"),
319 libc::ERROR_FILE_NOT_FOUND => (FileNotFound, "file not found"),
320 libc::ERROR_INVALID_NAME => (InvalidInput, "invalid file name"),
321 libc::WSAECONNREFUSED => (ConnectionRefused, "connection refused"),
322 libc::WSAECONNRESET => (ConnectionReset, "connection reset"),
323 libc::ERROR_ACCESS_DENIED | libc::WSAEACCES =>
324 (PermissionDenied, "permission denied"),
325 libc::WSAEWOULDBLOCK => {
326 (ResourceUnavailable, "resource temporarily unavailable")
328 libc::WSAENOTCONN => (NotConnected, "not connected"),
329 libc::WSAECONNABORTED => (ConnectionAborted, "connection aborted"),
330 libc::WSAEADDRNOTAVAIL => (ConnectionRefused, "address not available"),
331 libc::WSAEADDRINUSE => (ConnectionRefused, "address in use"),
332 libc::ERROR_BROKEN_PIPE => (EndOfFile, "the pipe has ended"),
333 libc::ERROR_OPERATION_ABORTED =>
334 (TimedOut, "operation timed out"),
335 libc::WSAEINVAL => (InvalidInput, "invalid argument"),
336 libc::ERROR_CALL_NOT_IMPLEMENTED =>
337 (IoUnavailable, "function not implemented"),
338 libc::ERROR_INVALID_HANDLE =>
339 (MismatchedFileTypeForOperation,
340 "invalid handle provided to function"),
341 libc::ERROR_NOTHING_TO_TERMINATE =>
342 (InvalidInput, "no process to kill"),
344 // libuv maps this error code to EISDIR. we do too. if it is found
345 // to be incorrect, we can add in some more machinery to only
346 // return this message when ERROR_INVALID_FUNCTION after certain
348 libc::ERROR_INVALID_FUNCTION => (InvalidInput,
349 "illegal operation on a directory"),
351 _ => (OtherIoError, "unknown error")
356 fn get_err(errno: i32) -> (IoErrorKind, &'static str) {
357 // FIXME: this should probably be a bit more descriptive...
359 libc::EOF => (EndOfFile, "end of file"),
360 libc::ECONNREFUSED => (ConnectionRefused, "connection refused"),
361 libc::ECONNRESET => (ConnectionReset, "connection reset"),
362 libc::EPERM | libc::EACCES =>
363 (PermissionDenied, "permission denied"),
364 libc::EPIPE => (BrokenPipe, "broken pipe"),
365 libc::ENOTCONN => (NotConnected, "not connected"),
366 libc::ECONNABORTED => (ConnectionAborted, "connection aborted"),
367 libc::EADDRNOTAVAIL => (ConnectionRefused, "address not available"),
368 libc::EADDRINUSE => (ConnectionRefused, "address in use"),
369 libc::ENOENT => (FileNotFound, "no such file or directory"),
370 libc::EISDIR => (InvalidInput, "illegal operation on a directory"),
371 libc::ENOSYS => (IoUnavailable, "function not implemented"),
372 libc::EINVAL => (InvalidInput, "invalid argument"),
374 (MismatchedFileTypeForOperation,
375 "file descriptor is not a TTY"),
376 libc::ETIMEDOUT => (TimedOut, "operation timed out"),
377 libc::ECANCELED => (TimedOut, "operation aborted"),
379 // These two constants can have the same value on some systems,
380 // but different values on others, so we can't use a match
382 x if x == libc::EAGAIN || x == libc::EWOULDBLOCK =>
383 (ResourceUnavailable, "resource temporarily unavailable"),
385 _ => (OtherIoError, "unknown error")
389 let (kind, desc) = get_err(errno as i32);
393 detail: if detail && kind == OtherIoError {
394 Some(os::error_string(errno).as_slice().chars().map(|c| c.to_lowercase()).collect())
401 /// Retrieve the last error to occur as a (detailed) IoError.
403 /// This uses the OS `errno`, and so there should not be any task
404 /// descheduling or migration (other than that performed by the
405 /// operating system) between the call(s) for which errors are
406 /// being checked and the call of this function.
407 pub fn last_error() -> IoError {
408 IoError::from_errno(os::errno() as uint, true)
411 fn from_rtio_error(err: rtio::IoError) -> IoError {
412 let rtio::IoError { code, extra, detail } = err;
413 let mut ioerr = IoError::from_errno(code, false);
414 ioerr.detail = detail;
415 ioerr.kind = match ioerr.kind {
416 TimedOut if extra > 0 => ShortWrite(extra),
423 impl fmt::Show for IoError {
424 fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
426 IoError { kind: OtherIoError, desc: "unknown error", detail: Some(ref detail) } =>
427 write!(fmt, "{}", detail),
428 IoError { detail: None, desc, .. } =>
429 write!(fmt, "{}", desc),
430 IoError { detail: Some(ref detail), desc, .. } =>
431 write!(fmt, "{} ({})", desc, detail)
436 /// A list specifying general categories of I/O error.
437 #[deriving(PartialEq, Clone, Show)]
438 pub enum IoErrorKind {
439 /// Any I/O error not part of this list.
441 /// The operation could not complete because end of file was reached.
443 /// The file was not found.
445 /// The file permissions disallowed access to this file.
447 /// A network connection failed for some reason not specified in this list.
449 /// The network operation failed because the network connection was closed.
451 /// The connection was refused by the remote server.
453 /// The connection was reset by the remote server.
455 /// The connection was aborted (terminated) by the remote server.
457 /// The network operation failed because it was not connected yet.
459 /// The operation failed because a pipe was closed.
461 /// A file already existed with that name.
463 /// No file exists at that location.
465 /// The path did not specify the type of file that this operation required. For example,
466 /// attempting to copy a directory with the `fs::copy()` operation will fail with this error.
467 MismatchedFileTypeForOperation,
468 /// The operation temporarily failed (for example, because a signal was received), and retrying
471 /// No I/O functionality is available for this task.
473 /// A parameter was incorrect in a way that caused an I/O error not part of this list.
475 /// The I/O operation's timeout expired, causing it to be canceled.
477 /// This write operation failed to write all of its data.
479 /// Normally the write() method on a Writer guarantees that all of its data
480 /// has been written, but some operations may be terminated after only
481 /// partially writing some data. An example of this is a timed out write
482 /// which successfully wrote a known number of bytes, but bailed out after
485 /// The payload contained as part of this variant is the number of bytes
486 /// which are known to have been successfully written.
488 /// The Reader returned 0 bytes from `read()` too many times.
492 /// A trait that lets you add a `detail` to an IoError easily
493 trait UpdateIoError<T> {
494 /// Returns an IoError with updated description and detail
495 fn update_err(self, desc: &'static str, detail: |&IoError| -> String) -> Self;
497 /// Returns an IoError with updated detail
498 fn update_detail(self, detail: |&IoError| -> String) -> Self;
500 /// Returns an IoError with update description
501 fn update_desc(self, desc: &'static str) -> Self;
504 impl<T> UpdateIoError<T> for IoResult<T> {
505 fn update_err(self, desc: &'static str, detail: |&IoError| -> String) -> IoResult<T> {
506 self.map_err(|mut e| {
507 let detail = detail(&e);
509 e.detail = Some(detail);
514 fn update_detail(self, detail: |&IoError| -> String) -> IoResult<T> {
515 self.map_err(|mut e| { e.detail = Some(detail(&e)); e })
518 fn update_desc(self, desc: &'static str) -> IoResult<T> {
519 self.map_err(|mut e| { e.desc = desc; e })
523 static NO_PROGRESS_LIMIT: uint = 1000;
525 /// A trait for objects which are byte-oriented streams. Readers are defined by
526 /// one method, `read`. This function will block until data is available,
527 /// filling in the provided buffer with any data read.
529 /// Readers are intended to be composable with one another. Many objects
530 /// throughout the I/O and related libraries take and provide types which
531 /// implement the `Reader` trait.
534 // Only method which need to get implemented for this trait
536 /// Read bytes, up to the length of `buf` and place them in `buf`.
537 /// Returns the number of bytes read. The number of bytes read may
538 /// be less than the number requested, even 0. Returns `Err` on EOF.
542 /// If an error occurs during this I/O operation, then it is returned as
543 /// `Err(IoError)`. Note that end-of-file is considered an error, and can be
544 /// inspected for in the error's `kind` field. Also note that reading 0
545 /// bytes is not considered an error in all circumstances
547 /// # Implementation Note
549 /// When implementing this method on a new Reader, you are strongly encouraged
550 /// not to return 0 if you can avoid it.
551 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint>;
553 // Convenient helper methods based on the above methods
555 /// Reads at least `min` bytes and places them in `buf`.
556 /// Returns the number of bytes read.
558 /// This will continue to call `read` until at least `min` bytes have been
559 /// read. If `read` returns 0 too many times, `NoProgress` will be
564 /// If an error occurs at any point, that error is returned, and no further
566 fn read_at_least(&mut self, min: uint, buf: &mut [u8]) -> IoResult<uint> {
569 detail: Some(String::from_str("the buffer is too short")),
570 ..standard_error(InvalidInput)
577 match self.read(buf.mut_slice_from(read)) {
580 if zeroes >= NO_PROGRESS_LIMIT {
581 return Err(standard_error(NoProgress));
588 err@Err(_) => return err
595 /// Reads a single byte. Returns `Err` on EOF.
596 fn read_byte(&mut self) -> IoResult<u8> {
598 try!(self.read_at_least(1, buf));
602 /// Reads up to `len` bytes and appends them to a vector.
603 /// Returns the number of bytes read. The number of bytes read may be
604 /// less than the number requested, even 0. Returns Err on EOF.
608 /// If an error occurs during this I/O operation, then it is returned
609 /// as `Err(IoError)`. See `read()` for more details.
610 fn push(&mut self, len: uint, buf: &mut Vec<u8>) -> IoResult<uint> {
611 let start_len = buf.len();
612 buf.reserve_additional(len);
615 let s = unsafe { slice_vec_capacity(buf, start_len, start_len + len) };
618 unsafe { buf.set_len(start_len + n) };
622 /// Reads at least `min` bytes, but no more than `len`, and appends them to
624 /// Returns the number of bytes read.
626 /// This will continue to call `read` until at least `min` bytes have been
627 /// read. If `read` returns 0 too many times, `NoProgress` will be
632 /// If an error occurs at any point, that error is returned, and no further
634 fn push_at_least(&mut self, min: uint, len: uint, buf: &mut Vec<u8>) -> IoResult<uint> {
637 detail: Some(String::from_str("the buffer is too short")),
638 ..standard_error(InvalidInput)
642 let start_len = buf.len();
643 buf.reserve_additional(len);
645 // we can't just use self.read_at_least(min, slice) because we need to push
646 // successful reads onto the vector before any returned errors.
651 let s = unsafe { slice_vec_capacity(buf, start_len + read, start_len + len) };
652 try!(self.read_at_least(1, s))
654 unsafe { buf.set_len(start_len + read) };
659 /// Reads exactly `len` bytes and gives you back a new vector of length
664 /// Fails with the same conditions as `read`. Additionally returns error
665 /// on EOF. Note that if an error is returned, then some number of bytes may
666 /// have already been consumed from the underlying reader, and they are lost
667 /// (not returned as part of the error). If this is unacceptable, then it is
668 /// recommended to use the `push_at_least` or `read` methods.
669 fn read_exact(&mut self, len: uint) -> IoResult<Vec<u8>> {
670 let mut buf = Vec::with_capacity(len);
671 match self.push_at_least(len, len, &mut buf) {
677 /// Reads all remaining bytes from the stream.
681 /// Returns any non-EOF error immediately. Previously read bytes are
682 /// discarded when an error is returned.
684 /// When EOF is encountered, all bytes read up to that point are returned.
685 fn read_to_end(&mut self) -> IoResult<Vec<u8>> {
686 let mut buf = Vec::with_capacity(DEFAULT_BUF_SIZE);
688 match self.push_at_least(1, DEFAULT_BUF_SIZE, &mut buf) {
690 Err(ref e) if e.kind == EndOfFile => break,
691 Err(e) => return Err(e)
697 /// Reads all of the remaining bytes of this stream, interpreting them as a
698 /// UTF-8 encoded stream. The corresponding string is returned.
702 /// This function returns all of the same errors as `read_to_end` with an
703 /// additional error if the reader's contents are not a valid sequence of
705 fn read_to_string(&mut self) -> IoResult<String> {
706 self.read_to_end().and_then(|s| {
707 match str::from_utf8(s.as_slice()) {
708 Some(s) => Ok(String::from_str(s)),
709 None => Err(standard_error(InvalidInput)),
714 /// Create an iterator that reads a single byte on
715 /// each iteration, until EOF.
719 /// Any error other than `EndOfFile` that is produced by the underlying Reader
720 /// is returned by the iterator and should be handled by the caller.
721 fn bytes<'r>(&'r mut self) -> extensions::Bytes<'r, Self> {
722 extensions::Bytes::new(self)
725 // Byte conversion helpers
727 /// Reads `n` little-endian unsigned integer bytes.
729 /// `n` must be between 1 and 8, inclusive.
730 fn read_le_uint_n(&mut self, nbytes: uint) -> IoResult<u64> {
731 assert!(nbytes > 0 && nbytes <= 8);
737 val += (try!(self.read_u8()) as u64) << pos;
744 /// Reads `n` little-endian signed integer bytes.
746 /// `n` must be between 1 and 8, inclusive.
747 fn read_le_int_n(&mut self, nbytes: uint) -> IoResult<i64> {
748 self.read_le_uint_n(nbytes).map(|i| extend_sign(i, nbytes))
751 /// Reads `n` big-endian unsigned integer bytes.
753 /// `n` must be between 1 and 8, inclusive.
754 fn read_be_uint_n(&mut self, nbytes: uint) -> IoResult<u64> {
755 assert!(nbytes > 0 && nbytes <= 8);
761 val += (try!(self.read_u8()) as u64) << i * 8;
766 /// Reads `n` big-endian signed integer bytes.
768 /// `n` must be between 1 and 8, inclusive.
769 fn read_be_int_n(&mut self, nbytes: uint) -> IoResult<i64> {
770 self.read_be_uint_n(nbytes).map(|i| extend_sign(i, nbytes))
773 /// Reads a little-endian unsigned integer.
775 /// The number of bytes returned is system-dependent.
776 fn read_le_uint(&mut self) -> IoResult<uint> {
777 self.read_le_uint_n(uint::BYTES).map(|i| i as uint)
780 /// Reads a little-endian integer.
782 /// The number of bytes returned is system-dependent.
783 fn read_le_int(&mut self) -> IoResult<int> {
784 self.read_le_int_n(int::BYTES).map(|i| i as int)
787 /// Reads a big-endian unsigned integer.
789 /// The number of bytes returned is system-dependent.
790 fn read_be_uint(&mut self) -> IoResult<uint> {
791 self.read_be_uint_n(uint::BYTES).map(|i| i as uint)
794 /// Reads a big-endian integer.
796 /// The number of bytes returned is system-dependent.
797 fn read_be_int(&mut self) -> IoResult<int> {
798 self.read_be_int_n(int::BYTES).map(|i| i as int)
801 /// Reads a big-endian `u64`.
803 /// `u64`s are 8 bytes long.
804 fn read_be_u64(&mut self) -> IoResult<u64> {
805 self.read_be_uint_n(8)
808 /// Reads a big-endian `u32`.
810 /// `u32`s are 4 bytes long.
811 fn read_be_u32(&mut self) -> IoResult<u32> {
812 self.read_be_uint_n(4).map(|i| i as u32)
815 /// Reads a big-endian `u16`.
817 /// `u16`s are 2 bytes long.
818 fn read_be_u16(&mut self) -> IoResult<u16> {
819 self.read_be_uint_n(2).map(|i| i as u16)
822 /// Reads a big-endian `i64`.
824 /// `i64`s are 8 bytes long.
825 fn read_be_i64(&mut self) -> IoResult<i64> {
826 self.read_be_int_n(8)
829 /// Reads a big-endian `i32`.
831 /// `i32`s are 4 bytes long.
832 fn read_be_i32(&mut self) -> IoResult<i32> {
833 self.read_be_int_n(4).map(|i| i as i32)
836 /// Reads a big-endian `i16`.
838 /// `i16`s are 2 bytes long.
839 fn read_be_i16(&mut self) -> IoResult<i16> {
840 self.read_be_int_n(2).map(|i| i as i16)
843 /// Reads a big-endian `f64`.
845 /// `f64`s are 8 byte, IEEE754 double-precision floating point numbers.
846 fn read_be_f64(&mut self) -> IoResult<f64> {
847 self.read_be_u64().map(|i| unsafe {
848 transmute::<u64, f64>(i)
852 /// Reads a big-endian `f32`.
854 /// `f32`s are 4 byte, IEEE754 single-precision floating point numbers.
855 fn read_be_f32(&mut self) -> IoResult<f32> {
856 self.read_be_u32().map(|i| unsafe {
857 transmute::<u32, f32>(i)
861 /// Reads a little-endian `u64`.
863 /// `u64`s are 8 bytes long.
864 fn read_le_u64(&mut self) -> IoResult<u64> {
865 self.read_le_uint_n(8)
868 /// Reads a little-endian `u32`.
870 /// `u32`s are 4 bytes long.
871 fn read_le_u32(&mut self) -> IoResult<u32> {
872 self.read_le_uint_n(4).map(|i| i as u32)
875 /// Reads a little-endian `u16`.
877 /// `u16`s are 2 bytes long.
878 fn read_le_u16(&mut self) -> IoResult<u16> {
879 self.read_le_uint_n(2).map(|i| i as u16)
882 /// Reads a little-endian `i64`.
884 /// `i64`s are 8 bytes long.
885 fn read_le_i64(&mut self) -> IoResult<i64> {
886 self.read_le_int_n(8)
889 /// Reads a little-endian `i32`.
891 /// `i32`s are 4 bytes long.
892 fn read_le_i32(&mut self) -> IoResult<i32> {
893 self.read_le_int_n(4).map(|i| i as i32)
896 /// Reads a little-endian `i16`.
898 /// `i16`s are 2 bytes long.
899 fn read_le_i16(&mut self) -> IoResult<i16> {
900 self.read_le_int_n(2).map(|i| i as i16)
903 /// Reads a little-endian `f64`.
905 /// `f64`s are 8 byte, IEEE754 double-precision floating point numbers.
906 fn read_le_f64(&mut self) -> IoResult<f64> {
907 self.read_le_u64().map(|i| unsafe {
908 transmute::<u64, f64>(i)
912 /// Reads a little-endian `f32`.
914 /// `f32`s are 4 byte, IEEE754 single-precision floating point numbers.
915 fn read_le_f32(&mut self) -> IoResult<f32> {
916 self.read_le_u32().map(|i| unsafe {
917 transmute::<u32, f32>(i)
923 /// `u8`s are 1 byte.
924 fn read_u8(&mut self) -> IoResult<u8> {
930 /// `i8`s are 1 byte.
931 fn read_i8(&mut self) -> IoResult<i8> {
932 self.read_byte().map(|i| i as i8)
935 /// Creates a wrapper around a mutable reference to the reader.
937 /// This is useful to allow applying adaptors while still
938 /// retaining ownership of the original value.
939 fn by_ref<'a>(&'a mut self) -> RefReader<'a, Self> {
940 RefReader { inner: self }
944 impl Reader for Box<Reader> {
945 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> { self.read(buf) }
948 impl<'a> Reader for &'a mut Reader {
949 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> { self.read(buf) }
952 /// Returns a slice of `v` between `start` and `end`.
954 /// Similar to `slice()` except this function only bounds the slice on the
955 /// capacity of `v`, not the length.
959 /// Fails when `start` or `end` point outside the capacity of `v`, or when
961 // Private function here because we aren't sure if we want to expose this as
962 // API yet. If so, it should be a method on Vec.
963 unsafe fn slice_vec_capacity<'a, T>(v: &'a mut Vec<T>, start: uint, end: uint) -> &'a mut [T] {
967 assert!(start <= end);
968 assert!(end <= v.capacity());
970 data: v.as_ptr().offset(start as int),
975 /// A `RefReader` is a struct implementing `Reader` which contains a reference
976 /// to another reader. This is often useful when composing streams.
982 /// # fn process_input<R: Reader>(r: R) {}
985 /// use std::io::util::LimitReader;
987 /// let mut stream = io::stdin();
989 /// // Only allow the function to process at most one kilobyte of input
991 /// let stream = LimitReader::new(stream.by_ref(), 1024);
992 /// process_input(stream);
995 /// // 'stream' is still available for use here
999 pub struct RefReader<'a, R> {
1000 /// The underlying reader which this is referencing
1004 impl<'a, R: Reader> Reader for RefReader<'a, R> {
1005 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> { self.inner.read(buf) }
1008 impl<'a, R: Buffer> Buffer for RefReader<'a, R> {
1009 fn fill_buf<'a>(&'a mut self) -> IoResult<&'a [u8]> { self.inner.fill_buf() }
1010 fn consume(&mut self, amt: uint) { self.inner.consume(amt) }
1013 fn extend_sign(val: u64, nbytes: uint) -> i64 {
1014 let shift = (8 - nbytes) * 8;
1015 (val << shift) as i64 >> shift
1018 /// A trait for objects which are byte-oriented streams. Writers are defined by
1019 /// one method, `write`. This function will block until the provided buffer of
1020 /// bytes has been entirely written, and it will return any failures which occur.
1022 /// Another commonly overridden method is the `flush` method for writers such as
1023 /// buffered writers.
1025 /// Writers are intended to be composable with one another. Many objects
1026 /// throughout the I/O and related libraries take and provide types which
1027 /// implement the `Writer` trait.
1029 /// Write the entirety of a given buffer
1033 /// If an error happens during the I/O operation, the error is returned as
1034 /// `Err`. Note that it is considered an error if the entire buffer could
1035 /// not be written, and if an error is returned then it is unknown how much
1036 /// data (if any) was actually written.
1037 fn write(&mut self, buf: &[u8]) -> IoResult<()>;
1039 /// Flush this output stream, ensuring that all intermediately buffered
1040 /// contents reach their destination.
1042 /// This is by default a no-op and implementers of the `Writer` trait should
1043 /// decide whether their stream needs to be buffered or not.
1044 fn flush(&mut self) -> IoResult<()> { Ok(()) }
1046 /// Writes a formatted string into this writer, returning any error
1049 /// This method is primarily used to interface with the `format_args!`
1050 /// macro, but it is rare that this should explicitly be called. The
1051 /// `write!` macro should be favored to invoke this method instead.
1055 /// This function will return any I/O error reported while formatting.
1056 fn write_fmt(&mut self, fmt: &fmt::Arguments) -> IoResult<()> {
1057 // Create a shim which translates a Writer to a FormatWriter and saves
1058 // off I/O errors. instead of discarding them
1059 struct Adaptor<'a, T> {
1061 error: IoResult<()>,
1063 impl<'a, T: Writer> fmt::FormatWriter for Adaptor<'a, T> {
1064 fn write(&mut self, bytes: &[u8]) -> fmt::Result {
1065 match self.inner.write(bytes) {
1068 self.error = Err(e);
1069 Err(fmt::WriteError)
1075 let mut output = Adaptor { inner: self, error: Ok(()) };
1076 match fmt::write(&mut output, fmt) {
1078 Err(..) => output.error
1082 /// Write a rust string into this sink.
1084 /// The bytes written will be the UTF-8 encoded version of the input string.
1085 /// If other encodings are desired, it is recommended to compose this stream
1086 /// with another performing the conversion, or to use `write` with a
1087 /// converted byte-array instead.
1089 fn write_str(&mut self, s: &str) -> IoResult<()> {
1090 self.write(s.as_bytes())
1093 /// Writes a string into this sink, and then writes a literal newline (`\n`)
1094 /// byte afterwards. Note that the writing of the newline is *not* atomic in
1095 /// the sense that the call to `write` is invoked twice (once with the
1096 /// string and once with a newline character).
1098 /// If other encodings or line ending flavors are desired, it is recommended
1099 /// that the `write` method is used specifically instead.
1101 fn write_line(&mut self, s: &str) -> IoResult<()> {
1102 self.write_str(s).and_then(|()| self.write(['\n' as u8]))
1105 /// Write a single char, encoded as UTF-8.
1107 fn write_char(&mut self, c: char) -> IoResult<()> {
1108 let mut buf = [0u8, ..4];
1109 let n = c.encode_utf8(buf.as_mut_slice());
1110 self.write(buf.slice_to(n))
1113 /// Write the result of passing n through `int::to_str_bytes`.
1115 fn write_int(&mut self, n: int) -> IoResult<()> {
1116 write!(self, "{:d}", n)
1119 /// Write the result of passing n through `uint::to_str_bytes`.
1121 fn write_uint(&mut self, n: uint) -> IoResult<()> {
1122 write!(self, "{:u}", n)
1125 /// Write a little-endian uint (number of bytes depends on system).
1127 fn write_le_uint(&mut self, n: uint) -> IoResult<()> {
1128 extensions::u64_to_le_bytes(n as u64, uint::BYTES, |v| self.write(v))
1131 /// Write a little-endian int (number of bytes depends on system).
1133 fn write_le_int(&mut self, n: int) -> IoResult<()> {
1134 extensions::u64_to_le_bytes(n as u64, int::BYTES, |v| self.write(v))
1137 /// Write a big-endian uint (number of bytes depends on system).
1139 fn write_be_uint(&mut self, n: uint) -> IoResult<()> {
1140 extensions::u64_to_be_bytes(n as u64, uint::BYTES, |v| self.write(v))
1143 /// Write a big-endian int (number of bytes depends on system).
1145 fn write_be_int(&mut self, n: int) -> IoResult<()> {
1146 extensions::u64_to_be_bytes(n as u64, int::BYTES, |v| self.write(v))
1149 /// Write a big-endian u64 (8 bytes).
1151 fn write_be_u64(&mut self, n: u64) -> IoResult<()> {
1152 extensions::u64_to_be_bytes(n, 8u, |v| self.write(v))
1155 /// Write a big-endian u32 (4 bytes).
1157 fn write_be_u32(&mut self, n: u32) -> IoResult<()> {
1158 extensions::u64_to_be_bytes(n as u64, 4u, |v| self.write(v))
1161 /// Write a big-endian u16 (2 bytes).
1163 fn write_be_u16(&mut self, n: u16) -> IoResult<()> {
1164 extensions::u64_to_be_bytes(n as u64, 2u, |v| self.write(v))
1167 /// Write a big-endian i64 (8 bytes).
1169 fn write_be_i64(&mut self, n: i64) -> IoResult<()> {
1170 extensions::u64_to_be_bytes(n as u64, 8u, |v| self.write(v))
1173 /// Write a big-endian i32 (4 bytes).
1175 fn write_be_i32(&mut self, n: i32) -> IoResult<()> {
1176 extensions::u64_to_be_bytes(n as u64, 4u, |v| self.write(v))
1179 /// Write a big-endian i16 (2 bytes).
1181 fn write_be_i16(&mut self, n: i16) -> IoResult<()> {
1182 extensions::u64_to_be_bytes(n as u64, 2u, |v| self.write(v))
1185 /// Write a big-endian IEEE754 double-precision floating-point (8 bytes).
1187 fn write_be_f64(&mut self, f: f64) -> IoResult<()> {
1189 self.write_be_u64(transmute(f))
1193 /// Write a big-endian IEEE754 single-precision floating-point (4 bytes).
1195 fn write_be_f32(&mut self, f: f32) -> IoResult<()> {
1197 self.write_be_u32(transmute(f))
1201 /// Write a little-endian u64 (8 bytes).
1203 fn write_le_u64(&mut self, n: u64) -> IoResult<()> {
1204 extensions::u64_to_le_bytes(n, 8u, |v| self.write(v))
1207 /// Write a little-endian u32 (4 bytes).
1209 fn write_le_u32(&mut self, n: u32) -> IoResult<()> {
1210 extensions::u64_to_le_bytes(n as u64, 4u, |v| self.write(v))
1213 /// Write a little-endian u16 (2 bytes).
1215 fn write_le_u16(&mut self, n: u16) -> IoResult<()> {
1216 extensions::u64_to_le_bytes(n as u64, 2u, |v| self.write(v))
1219 /// Write a little-endian i64 (8 bytes).
1221 fn write_le_i64(&mut self, n: i64) -> IoResult<()> {
1222 extensions::u64_to_le_bytes(n as u64, 8u, |v| self.write(v))
1225 /// Write a little-endian i32 (4 bytes).
1227 fn write_le_i32(&mut self, n: i32) -> IoResult<()> {
1228 extensions::u64_to_le_bytes(n as u64, 4u, |v| self.write(v))
1231 /// Write a little-endian i16 (2 bytes).
1233 fn write_le_i16(&mut self, n: i16) -> IoResult<()> {
1234 extensions::u64_to_le_bytes(n as u64, 2u, |v| self.write(v))
1237 /// Write a little-endian IEEE754 double-precision floating-point
1240 fn write_le_f64(&mut self, f: f64) -> IoResult<()> {
1242 self.write_le_u64(transmute(f))
1246 /// Write a little-endian IEEE754 single-precision floating-point
1249 fn write_le_f32(&mut self, f: f32) -> IoResult<()> {
1251 self.write_le_u32(transmute(f))
1255 /// Write a u8 (1 byte).
1257 fn write_u8(&mut self, n: u8) -> IoResult<()> {
1261 /// Write an i8 (1 byte).
1263 fn write_i8(&mut self, n: i8) -> IoResult<()> {
1264 self.write([n as u8])
1267 /// Creates a wrapper around a mutable reference to the writer.
1269 /// This is useful to allow applying wrappers while still
1270 /// retaining ownership of the original value.
1272 fn by_ref<'a>(&'a mut self) -> RefWriter<'a, Self> {
1273 RefWriter { inner: self }
1277 impl Writer for Box<Writer> {
1279 fn write(&mut self, buf: &[u8]) -> IoResult<()> { self.write(buf) }
1282 fn flush(&mut self) -> IoResult<()> { self.flush() }
1285 impl<'a> Writer for &'a mut Writer {
1287 fn write(&mut self, buf: &[u8]) -> IoResult<()> { self.write(buf) }
1290 fn flush(&mut self) -> IoResult<()> { self.flush() }
1293 /// A `RefWriter` is a struct implementing `Writer` which contains a reference
1294 /// to another writer. This is often useful when composing streams.
1300 /// # fn process_input<R: Reader>(r: R) {}
1302 /// use std::io::util::TeeReader;
1303 /// use std::io::{stdin, MemWriter};
1305 /// let mut output = MemWriter::new();
1308 /// // Don't give ownership of 'output' to the 'tee'. Instead we keep a
1309 /// // handle to it in the outer scope
1310 /// let mut tee = TeeReader::new(stdin(), output.by_ref());
1311 /// process_input(tee);
1314 /// println!("input processed: {}", output.unwrap());
1317 pub struct RefWriter<'a, W> {
1318 /// The underlying writer which this is referencing
1322 impl<'a, W: Writer> Writer for RefWriter<'a, W> {
1324 fn write(&mut self, buf: &[u8]) -> IoResult<()> { self.inner.write(buf) }
1327 fn flush(&mut self) -> IoResult<()> { self.inner.flush() }
1331 /// A Stream is a readable and a writable object. Data written is typically
1332 /// received by the object which reads receive data from.
1333 pub trait Stream: Reader + Writer { }
1335 impl<T: Reader + Writer> Stream for T {}
1337 /// An iterator that reads a line on each iteration,
1338 /// until `.read_line()` encounters `EndOfFile`.
1340 /// # Notes about the Iteration Protocol
1342 /// The `Lines` may yield `None` and thus terminate
1343 /// an iteration, but continue to yield elements if iteration
1344 /// is attempted again.
1348 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1349 /// is returned by the iterator and should be handled by the caller.
1350 pub struct Lines<'r, T> {
1354 impl<'r, T: Buffer> Iterator<IoResult<String>> for Lines<'r, T> {
1355 fn next(&mut self) -> Option<IoResult<String>> {
1356 match self.buffer.read_line() {
1357 Ok(x) => Some(Ok(x)),
1358 Err(IoError { kind: EndOfFile, ..}) => None,
1359 Err(y) => Some(Err(y))
1364 /// An iterator that reads a utf8-encoded character on each iteration,
1365 /// until `.read_char()` encounters `EndOfFile`.
1367 /// # Notes about the Iteration Protocol
1369 /// The `Chars` may yield `None` and thus terminate
1370 /// an iteration, but continue to yield elements if iteration
1371 /// is attempted again.
1375 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1376 /// is returned by the iterator and should be handled by the caller.
1377 pub struct Chars<'r, T> {
1381 impl<'r, T: Buffer> Iterator<IoResult<char>> for Chars<'r, T> {
1382 fn next(&mut self) -> Option<IoResult<char>> {
1383 match self.buffer.read_char() {
1384 Ok(x) => Some(Ok(x)),
1385 Err(IoError { kind: EndOfFile, ..}) => None,
1386 Err(y) => Some(Err(y))
1391 /// A Buffer is a type of reader which has some form of internal buffering to
1392 /// allow certain kinds of reading operations to be more optimized than others.
1393 /// This type extends the `Reader` trait with a few methods that are not
1394 /// possible to reasonably implement with purely a read interface.
1395 pub trait Buffer: Reader {
1396 /// Fills the internal buffer of this object, returning the buffer contents.
1397 /// Note that none of the contents will be "read" in the sense that later
1398 /// calling `read` may return the same contents.
1400 /// The `consume` function must be called with the number of bytes that are
1401 /// consumed from this buffer returned to ensure that the bytes are never
1406 /// This function will return an I/O error if the underlying reader was
1407 /// read, but returned an error. Note that it is not an error to return a
1408 /// 0-length buffer.
1409 fn fill_buf<'a>(&'a mut self) -> IoResult<&'a [u8]>;
1411 /// Tells this buffer that `amt` bytes have been consumed from the buffer,
1412 /// so they should no longer be returned in calls to `read`.
1413 fn consume(&mut self, amt: uint);
1415 /// Reads the next line of input, interpreted as a sequence of UTF-8
1416 /// encoded unicode codepoints. If a newline is encountered, then the
1417 /// newline is contained in the returned string.
1424 /// let mut reader = io::stdin();
1425 /// let input = reader.read_line().ok().unwrap_or("nothing".to_string());
1430 /// This function has the same error semantics as `read_until`:
1432 /// * All non-EOF errors will be returned immediately
1433 /// * If an error is returned previously consumed bytes are lost
1434 /// * EOF is only returned if no bytes have been read
1435 /// * Reach EOF may mean that the delimiter is not present in the return
1438 /// Additionally, this function can fail if the line of input read is not a
1439 /// valid UTF-8 sequence of bytes.
1440 fn read_line(&mut self) -> IoResult<String> {
1441 self.read_until('\n' as u8).and_then(|line|
1442 match str::from_utf8(line.as_slice()) {
1443 Some(s) => Ok(String::from_str(s)),
1444 None => Err(standard_error(InvalidInput)),
1449 /// Create an iterator that reads a line on each iteration until EOF.
1453 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1454 /// is returned by the iterator and should be handled by the caller.
1455 fn lines<'r>(&'r mut self) -> Lines<'r, Self> {
1456 Lines { buffer: self }
1459 /// Reads a sequence of bytes leading up to a specified delimiter. Once the
1460 /// specified byte is encountered, reading ceases and the bytes up to and
1461 /// including the delimiter are returned.
1465 /// If any I/O error is encountered other than EOF, the error is immediately
1466 /// returned. Note that this may discard bytes which have already been read,
1467 /// and those bytes will *not* be returned. It is recommended to use other
1468 /// methods if this case is worrying.
1470 /// If EOF is encountered, then this function will return EOF if 0 bytes
1471 /// have been read, otherwise the pending byte buffer is returned. This
1472 /// is the reason that the byte buffer returned may not always contain the
1474 fn read_until(&mut self, byte: u8) -> IoResult<Vec<u8>> {
1475 let mut res = Vec::new();
1480 let available = match self.fill_buf() {
1482 Err(ref e) if res.len() > 0 && e.kind == EndOfFile => {
1486 Err(e) => return Err(e)
1488 match available.iter().position(|&b| b == byte) {
1490 res.push_all(available.slice_to(i + 1));
1495 res.push_all(available);
1496 used = available.len();
1506 /// Reads the next utf8-encoded character from the underlying stream.
1510 /// If an I/O error occurs, or EOF, then this function will return `Err`.
1511 /// This function will also return error if the stream does not contain a
1512 /// valid utf-8 encoded codepoint as the next few bytes in the stream.
1513 fn read_char(&mut self) -> IoResult<char> {
1514 let first_byte = try!(self.read_byte());
1515 let width = str::utf8_char_width(first_byte);
1516 if width == 1 { return Ok(first_byte as char) }
1517 if width == 0 { return Err(standard_error(InvalidInput)) } // not utf8
1518 let mut buf = [first_byte, 0, 0, 0];
1521 while start < width {
1522 match try!(self.read(buf.mut_slice(start, width))) {
1523 n if n == width - start => break,
1524 n if n < width - start => { start += n; }
1525 _ => return Err(standard_error(InvalidInput)),
1529 match str::from_utf8(buf.slice_to(width)) {
1530 Some(s) => Ok(s.char_at(0)),
1531 None => Err(standard_error(InvalidInput))
1535 /// Create an iterator that reads a utf8-encoded character on each iteration
1540 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1541 /// is returned by the iterator and should be handled by the caller.
1542 fn chars<'r>(&'r mut self) -> Chars<'r, Self> {
1543 Chars { buffer: self }
1547 /// When seeking, the resulting cursor is offset from a base by the offset given
1548 /// to the `seek` function. The base used is specified by this enumeration.
1549 pub enum SeekStyle {
1550 /// Seek from the beginning of the stream
1552 /// Seek from the end of the stream
1554 /// Seek from the current position
1558 /// An object implementing `Seek` internally has some form of cursor which can
1559 /// be moved within a stream of bytes. The stream typically has a fixed size,
1560 /// allowing seeking relative to either end.
1562 /// Return position of file cursor in the stream
1563 fn tell(&self) -> IoResult<u64>;
1565 /// Seek to an offset in a stream
1567 /// A successful seek clears the EOF indicator. Seeking beyond EOF is
1568 /// allowed, but seeking before position 0 is not allowed.
1572 /// * Seeking to a negative offset is considered an error
1573 /// * Seeking past the end of the stream does not modify the underlying
1574 /// stream, but the next write may cause the previous data to be filled in
1575 /// with a bit pattern.
1576 fn seek(&mut self, pos: i64, style: SeekStyle) -> IoResult<()>;
1579 /// A listener is a value that can consume itself to start listening for
1582 /// Doing so produces some sort of Acceptor.
1583 pub trait Listener<T, A: Acceptor<T>> {
1584 /// Spin up the listener and start queuing incoming connections
1588 /// Returns `Err` if this listener could not be bound to listen for
1589 /// connections. In all cases, this listener is consumed.
1590 fn listen(self) -> IoResult<A>;
1593 /// An acceptor is a value that presents incoming connections
1594 pub trait Acceptor<T> {
1595 /// Wait for and accept an incoming connection
1599 /// Returns `Err` if an I/O error is encountered.
1600 fn accept(&mut self) -> IoResult<T>;
1602 /// Create an iterator over incoming connection attempts.
1604 /// Note that I/O errors will be yielded by the iterator itself.
1605 fn incoming<'r>(&'r mut self) -> IncomingConnections<'r, Self> {
1606 IncomingConnections { inc: self }
1610 /// An infinite iterator over incoming connection attempts.
1611 /// Calling `next` will block the task until a connection is attempted.
1613 /// Since connection attempts can continue forever, this iterator always returns
1614 /// `Some`. The `Some` contains the `IoResult` representing whether the
1615 /// connection attempt was successful. A successful connection will be wrapped
1616 /// in `Ok`. A failed connection is represented as an `Err`.
1617 pub struct IncomingConnections<'a, A> {
1621 impl<'a, T, A: Acceptor<T>> Iterator<IoResult<T>> for IncomingConnections<'a, A> {
1622 fn next(&mut self) -> Option<IoResult<T>> {
1623 Some(self.inc.accept())
1627 /// Creates a standard error for a commonly used flavor of error. The `detail`
1628 /// field of the returned error will always be `None`.
1635 /// let eof = io::standard_error(io::EndOfFile);
1636 /// let einval = io::standard_error(io::InvalidInput);
1638 pub fn standard_error(kind: IoErrorKind) -> IoError {
1639 let desc = match kind {
1640 EndOfFile => "end of file",
1641 IoUnavailable => "I/O is unavailable",
1642 InvalidInput => "invalid input",
1643 OtherIoError => "unknown I/O error",
1644 FileNotFound => "file not found",
1645 PermissionDenied => "permission denied",
1646 ConnectionFailed => "connection failed",
1647 Closed => "stream is closed",
1648 ConnectionRefused => "connection refused",
1649 ConnectionReset => "connection reset",
1650 ConnectionAborted => "connection aborted",
1651 NotConnected => "not connected",
1652 BrokenPipe => "broken pipe",
1653 PathAlreadyExists => "file already exists",
1654 PathDoesntExist => "no such file",
1655 MismatchedFileTypeForOperation => "mismatched file type",
1656 ResourceUnavailable => "resource unavailable",
1657 TimedOut => "operation timed out",
1658 ShortWrite(..) => "short write",
1659 NoProgress => "no progress",
1668 /// A mode specifies how a file should be opened or created. These modes are
1669 /// passed to `File::open_mode` and are used to control where the file is
1670 /// positioned when it is initially opened.
1672 /// Opens a file positioned at the beginning.
1674 /// Opens a file positioned at EOF.
1676 /// Opens a file, truncating it if it already exists.
1680 /// Access permissions with which the file should be opened. `File`s
1681 /// opened with `Read` will return an error if written to.
1682 pub enum FileAccess {
1683 /// Read-only access, requests to write will result in an error
1685 /// Write-only access, requests to read will result in an error
1687 /// Read-write access, no requests are denied by default
1691 /// Different kinds of files which can be identified by a call to stat
1692 #[deriving(PartialEq, Show, Hash)]
1694 /// This is a normal file, corresponding to `S_IFREG`
1697 /// This file is a directory, corresponding to `S_IFDIR`
1700 /// This file is a named pipe, corresponding to `S_IFIFO`
1703 /// This file is a block device, corresponding to `S_IFBLK`
1706 /// This file is a symbolic link to another file, corresponding to `S_IFLNK`
1709 /// The type of this file is not recognized as one of the other categories
1713 /// A structure used to describe metadata information about a file. This
1714 /// structure is created through the `stat` method on a `Path`.
1721 /// let info = match Path::new("foo.txt").stat() {
1722 /// Ok(stat) => stat,
1723 /// Err(e) => fail!("couldn't read foo.txt: {}", e),
1726 /// println!("byte size: {}", info.size);
1730 pub struct FileStat {
1731 /// The size of the file, in bytes
1733 /// The kind of file this path points to (directory, file, pipe, etc.)
1735 /// The file permissions currently on the file
1736 pub perm: FilePermission,
1738 // FIXME(#10301): These time fields are pretty useless without an actual
1739 // time representation, what are the milliseconds relative
1742 /// The time that the file was created at, in platform-dependent
1745 /// The time that this file was last modified, in platform-dependent
1748 /// The time that this file was last accessed, in platform-dependent
1752 /// Information returned by stat() which is not guaranteed to be
1753 /// platform-independent. This information may be useful on some platforms,
1754 /// but it may have different meanings or no meaning at all on other
1757 /// Usage of this field is discouraged, but if access is desired then the
1758 /// fields are located here.
1760 pub unstable: UnstableFileStat,
1763 /// This structure represents all of the possible information which can be
1764 /// returned from a `stat` syscall which is not contained in the `FileStat`
1765 /// structure. This information is not necessarily platform independent, and may
1766 /// have different meanings or no meaning at all on some platforms.
1769 pub struct UnstableFileStat {
1770 /// The ID of the device containing the file.
1772 /// The file serial number.
1776 /// The number of hard links to this file.
1778 /// The user ID of the file.
1780 /// The group ID of the file.
1782 /// The optimal block size for I/O.
1784 /// The blocks allocated for this file.
1786 /// User-defined flags for the file.
1788 /// The file generation number.
1793 #[doc="A set of permissions for a file or directory is represented
1794 by a set of flags which are or'd together."]
1797 flags FilePermission: u32 {
1798 static UserRead = 0o400,
1799 static UserWrite = 0o200,
1800 static UserExecute = 0o100,
1801 static GroupRead = 0o040,
1802 static GroupWrite = 0o020,
1803 static GroupExecute = 0o010,
1804 static OtherRead = 0o004,
1805 static OtherWrite = 0o002,
1806 static OtherExecute = 0o001,
1808 static UserRWX = UserRead.bits | UserWrite.bits | UserExecute.bits,
1809 static GroupRWX = GroupRead.bits | GroupWrite.bits | GroupExecute.bits,
1810 static OtherRWX = OtherRead.bits | OtherWrite.bits | OtherExecute.bits,
1812 #[doc="Permissions for user owned files, equivalent to 0644 on
1813 unix-like systems."]
1814 static UserFile = UserRead.bits | UserWrite.bits | GroupRead.bits | OtherRead.bits,
1816 #[doc="Permissions for user owned directories, equivalent to 0755 on
1817 unix-like systems."]
1818 static UserDir = UserRWX.bits | GroupRead.bits | GroupExecute.bits |
1819 OtherRead.bits | OtherExecute.bits,
1821 #[doc="Permissions for user owned executables, equivalent to 0755
1822 on unix-like systems."]
1823 static UserExec = UserDir.bits,
1825 #[doc="All possible permissions enabled."]
1826 static AllPermissions = UserRWX.bits | GroupRWX.bits | OtherRWX.bits
1832 use super::{IoResult, Reader, MemReader, NoProgress, InvalidInput};
1836 #[deriving(Clone, PartialEq, Show)]
1837 enum BadReaderBehavior {
1842 struct BadReader<T> {
1844 behavior: Vec<BadReaderBehavior>,
1847 impl<T: Reader> BadReader<T> {
1848 fn new(r: T, behavior: Vec<BadReaderBehavior>) -> BadReader<T> {
1849 BadReader { behavior: behavior, r: r }
1853 impl<T: Reader> Reader for BadReader<T> {
1854 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> {
1855 let BadReader { ref mut behavior, ref mut r } = *self;
1857 if behavior.is_empty() {
1858 // fall back on good
1861 match behavior.as_mut_slice()[0] {
1862 GoodBehavior(0) => (),
1863 GoodBehavior(ref mut x) => {
1867 BadBehavior(0) => (),
1868 BadBehavior(ref mut x) => {
1879 fn test_read_at_least() {
1880 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1881 Vec::from_slice([GoodBehavior(uint::MAX)]));
1882 let mut buf = [0u8, ..5];
1883 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1884 assert!(r.read_exact(5).unwrap().len() == 5); // read_exact uses read_at_least
1885 assert!(r.read_at_least(0, buf).is_ok());
1887 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1888 Vec::from_slice([BadBehavior(50), GoodBehavior(uint::MAX)]));
1889 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1891 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1892 Vec::from_slice([BadBehavior(1), GoodBehavior(1),
1893 BadBehavior(50), GoodBehavior(uint::MAX)]));
1894 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1895 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1897 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1898 Vec::from_slice([BadBehavior(uint::MAX)]));
1899 assert_eq!(r.read_at_least(1, buf).unwrap_err().kind, NoProgress);
1901 let mut r = MemReader::new(Vec::from_slice(b"hello, world!"));
1902 assert_eq!(r.read_at_least(5, buf).unwrap(), 5);
1903 assert_eq!(r.read_at_least(6, buf).unwrap_err().kind, InvalidInput);
1907 fn test_push_at_least() {
1908 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1909 Vec::from_slice([GoodBehavior(uint::MAX)]));
1910 let mut buf = Vec::new();
1911 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1912 assert!(r.push_at_least(0, 5, &mut buf).is_ok());
1914 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1915 Vec::from_slice([BadBehavior(50), GoodBehavior(uint::MAX)]));
1916 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1918 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1919 Vec::from_slice([BadBehavior(1), GoodBehavior(1),
1920 BadBehavior(50), GoodBehavior(uint::MAX)]));
1921 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1922 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1924 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1925 Vec::from_slice([BadBehavior(uint::MAX)]));
1926 assert_eq!(r.push_at_least(1, 5, &mut buf).unwrap_err().kind, NoProgress);
1928 let mut r = MemReader::new(Vec::from_slice(b"hello, world!"));
1929 assert_eq!(r.push_at_least(5, 1, &mut buf).unwrap_err().kind, InvalidInput);