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().lines() {
36 print!("{}", line.unwrap());
40 * Read a complete 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)]
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;
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;
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};
109 let listener = TcpListener::bind("127.0.0.1", 80);
111 // bind the listener to the specified address
112 let mut acceptor = listener.listen();
114 fn handle_client(mut stream: TcpStream) {
116 # &mut stream; // silence unused mutability/variable warning
118 // accept connections and process them, spawning a new tasks for each one
119 for stream in acceptor.incoming() {
121 Err(e) => { /* connection failed */ }
122 Ok(stream) => spawn(proc() {
123 // connection succeeded
124 handle_client(stream)
129 // close the socket server
137 I/O is an area where nearly every operation can result in unexpected
138 errors. Errors should be painfully visible when they happen, and handling them
139 should be easy to work with. It should be convenient to handle specific I/O
140 errors, and it should also be convenient to not deal with I/O errors.
142 Rust's I/O employs a combination of techniques to reduce boilerplate
143 while still providing feedback about errors. The basic strategy:
145 * All I/O operations return `IoResult<T>` which is equivalent to
146 `Result<T, IoError>`. The `Result` type is defined in the `std::result`
148 * If the `Result` type goes unused, then the compiler will by default emit a
149 warning about the unused result. This is because `Result` has the
150 `#[must_use]` attribute.
151 * Common traits are implemented for `IoResult`, e.g.
152 `impl<R: Reader> Reader for IoResult<R>`, so that error values do not have
153 to be 'unwrapped' before use.
155 These features combine in the API to allow for expressions like
156 `File::create(&Path::new("diary.txt")).write(b"Met a girl.\n")`
157 without having to worry about whether "diary.txt" exists or whether
158 the write succeeds. As written, if either `new` or `write_line`
159 encounters an error then the result of the entire expression will
162 If you wanted to handle the error though you might write:
165 # #![allow(unused_must_use)]
168 match File::create(&Path::new("diary.txt")).write(b"Met a girl.\n") {
169 Ok(()) => (), // succeeded
170 Err(e) => println!("failed to write to my diary: {}", e),
173 # ::std::io::fs::unlink(&Path::new("diary.txt"));
176 So what actually happens if `create` encounters an error?
177 It's important to know that what `new` returns is not a `File`
178 but an `IoResult<File>`. If the file does not open, then `new` will simply
179 return `Err(..)`. Because there is an implementation of `Writer` (the trait
180 required ultimately required for types to implement `write_line`) there is no
181 need to inspect or unwrap the `IoResult<File>` and we simply call `write_line`
182 on it. If `new` returned an `Err(..)` then the followup call to `write_line`
183 will also return an error.
187 Explicit pattern matching on `IoResult`s can get quite verbose, especially
188 when performing many I/O operations. Some examples (like those above) are
189 alleviated with extra methods implemented on `IoResult`, but others have more
190 complex interdependencies among each I/O operation.
192 The `try!` macro from `std::macros` is provided as a method of early-return
193 inside `Result`-returning functions. It expands to an early-return on `Err`
194 and otherwise unwraps the contained `Ok` value.
196 If you wanted to read several `u32`s from a file and return their product:
199 use std::io::{File, IoResult};
201 fn file_product(p: &Path) -> IoResult<u32> {
202 let mut f = File::open(p);
203 let x1 = try!(f.read_le_u32());
204 let x2 = try!(f.read_le_u32());
209 match file_product(&Path::new("numbers.bin")) {
210 Ok(x) => println!("{}", x),
211 Err(e) => println!("Failed to read numbers!")
215 With `try!` in `file_product`, each `read_le_u32` need not be directly
216 concerned with error handling; instead its caller is responsible for
217 responding to errors that may occur while attempting to read the numbers.
222 #![deny(unused_must_use)]
225 use collections::Collection;
226 use default::Default;
232 use ops::{BitOr, BitXor, BitAnd, Sub, Not};
233 use option::{Option, Some, None};
236 use result::{Ok, Err, Result};
238 use slice::{AsSlice, ImmutableSlice};
239 use str::{Str, StrSlice};
243 use unicode::char::UnicodeChar;
247 pub use self::stdio::stdin;
248 pub use self::stdio::stdout;
249 pub use self::stdio::stderr;
250 pub use self::stdio::print;
251 pub use self::stdio::println;
253 pub use self::fs::File;
254 pub use self::timer::Timer;
255 pub use self::net::ip::IpAddr;
256 pub use self::net::tcp::TcpListener;
257 pub use self::net::tcp::TcpStream;
258 pub use self::net::udp::UdpStream;
259 pub use self::pipe::PipeStream;
260 pub use self::process::{Process, Command};
261 pub use self::tempfile::TempDir;
263 pub use self::mem::{MemReader, BufReader, MemWriter, BufWriter};
264 pub use self::buffered::{BufferedReader, BufferedWriter, BufferedStream,
266 pub use self::comm_adapters::{ChanReader, ChanWriter};
283 /// The default buffer size for various I/O operations
284 // libuv recommends 64k buffers to maximize throughput
285 // https://groups.google.com/forum/#!topic/libuv/oQO1HJAIDdA
286 const DEFAULT_BUF_SIZE: uint = 1024 * 64;
288 /// A convenient typedef of the return value of any I/O action.
289 pub type IoResult<T> = Result<T, IoError>;
291 /// The type passed to I/O condition handlers to indicate error
295 /// Is something like this sufficient? It's kind of archaic
296 #[deriving(PartialEq, Eq, Clone)]
298 /// An enumeration which can be matched against for determining the flavor
300 pub kind: IoErrorKind,
301 /// A human-readable description about the error
302 pub desc: &'static str,
303 /// Detailed information about this error, not always available
304 pub detail: Option<String>
308 /// Convert an `errno` value into an `IoError`.
310 /// If `detail` is `true`, the `detail` field of the `IoError`
311 /// struct is filled with an allocated string describing the error
312 /// in more detail, retrieved from the operating system.
313 pub fn from_errno(errno: uint, detail: bool) -> IoError {
316 fn get_err(errno: i32) -> (IoErrorKind, &'static str) {
318 libc::EOF => (EndOfFile, "end of file"),
319 libc::ERROR_NO_DATA => (BrokenPipe, "the pipe is being closed"),
320 libc::ERROR_FILE_NOT_FOUND => (FileNotFound, "file not found"),
321 libc::ERROR_INVALID_NAME => (InvalidInput, "invalid file name"),
322 libc::WSAECONNREFUSED => (ConnectionRefused, "connection refused"),
323 libc::WSAECONNRESET => (ConnectionReset, "connection reset"),
324 libc::ERROR_ACCESS_DENIED | libc::WSAEACCES =>
325 (PermissionDenied, "permission denied"),
326 libc::WSAEWOULDBLOCK => {
327 (ResourceUnavailable, "resource temporarily unavailable")
329 libc::WSAENOTCONN => (NotConnected, "not connected"),
330 libc::WSAECONNABORTED => (ConnectionAborted, "connection aborted"),
331 libc::WSAEADDRNOTAVAIL => (ConnectionRefused, "address not available"),
332 libc::WSAEADDRINUSE => (ConnectionRefused, "address in use"),
333 libc::ERROR_BROKEN_PIPE => (EndOfFile, "the pipe has ended"),
334 libc::ERROR_OPERATION_ABORTED =>
335 (TimedOut, "operation timed out"),
336 libc::WSAEINVAL => (InvalidInput, "invalid argument"),
337 libc::ERROR_CALL_NOT_IMPLEMENTED =>
338 (IoUnavailable, "function not implemented"),
339 libc::ERROR_INVALID_HANDLE =>
340 (MismatchedFileTypeForOperation,
341 "invalid handle provided to function"),
342 libc::ERROR_NOTHING_TO_TERMINATE =>
343 (InvalidInput, "no process to kill"),
345 // libuv maps this error code to EISDIR. we do too. if it is found
346 // to be incorrect, we can add in some more machinery to only
347 // return this message when ERROR_INVALID_FUNCTION after certain
349 libc::ERROR_INVALID_FUNCTION => (InvalidInput,
350 "illegal operation on a directory"),
352 _ => (OtherIoError, "unknown error")
357 fn get_err(errno: i32) -> (IoErrorKind, &'static str) {
358 // FIXME: this should probably be a bit more descriptive...
360 libc::EOF => (EndOfFile, "end of file"),
361 libc::ECONNREFUSED => (ConnectionRefused, "connection refused"),
362 libc::ECONNRESET => (ConnectionReset, "connection reset"),
363 libc::EPERM | libc::EACCES =>
364 (PermissionDenied, "permission denied"),
365 libc::EPIPE => (BrokenPipe, "broken pipe"),
366 libc::ENOTCONN => (NotConnected, "not connected"),
367 libc::ECONNABORTED => (ConnectionAborted, "connection aborted"),
368 libc::EADDRNOTAVAIL => (ConnectionRefused, "address not available"),
369 libc::EADDRINUSE => (ConnectionRefused, "address in use"),
370 libc::ENOENT => (FileNotFound, "no such file or directory"),
371 libc::EISDIR => (InvalidInput, "illegal operation on a directory"),
372 libc::ENOSYS => (IoUnavailable, "function not implemented"),
373 libc::EINVAL => (InvalidInput, "invalid argument"),
375 (MismatchedFileTypeForOperation,
376 "file descriptor is not a TTY"),
377 libc::ETIMEDOUT => (TimedOut, "operation timed out"),
378 libc::ECANCELED => (TimedOut, "operation aborted"),
380 // These two constants can have the same value on some systems,
381 // but different values on others, so we can't use a match
383 x if x == libc::EAGAIN || x == libc::EWOULDBLOCK =>
384 (ResourceUnavailable, "resource temporarily unavailable"),
386 _ => (OtherIoError, "unknown error")
390 let (kind, desc) = get_err(errno as i32);
394 detail: if detail && kind == OtherIoError {
395 Some(os::error_string(errno).as_slice().chars().map(|c| c.to_lowercase()).collect())
402 /// Retrieve the last error to occur as a (detailed) IoError.
404 /// This uses the OS `errno`, and so there should not be any task
405 /// descheduling or migration (other than that performed by the
406 /// operating system) between the call(s) for which errors are
407 /// being checked and the call of this function.
408 pub fn last_error() -> IoError {
409 IoError::from_errno(os::errno() as uint, true)
412 fn from_rtio_error(err: rtio::IoError) -> IoError {
413 let rtio::IoError { code, extra, detail } = err;
414 let mut ioerr = IoError::from_errno(code, false);
415 ioerr.detail = detail;
416 ioerr.kind = match ioerr.kind {
417 TimedOut if extra > 0 => ShortWrite(extra),
424 impl fmt::Show for IoError {
425 fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
427 IoError { kind: OtherIoError, desc: "unknown error", detail: Some(ref detail) } =>
428 write!(fmt, "{}", detail),
429 IoError { detail: None, desc, .. } =>
430 write!(fmt, "{}", desc),
431 IoError { detail: Some(ref detail), desc, .. } =>
432 write!(fmt, "{} ({})", desc, detail)
437 /// A list specifying general categories of I/O error.
438 #[deriving(PartialEq, Eq, Clone, Show)]
439 pub enum IoErrorKind {
440 /// Any I/O error not part of this list.
442 /// The operation could not complete because end of file was reached.
444 /// The file was not found.
446 /// The file permissions disallowed access to this file.
448 /// A network connection failed for some reason not specified in this list.
450 /// The network operation failed because the network connection was closed.
452 /// The connection was refused by the remote server.
454 /// The connection was reset by the remote server.
456 /// The connection was aborted (terminated) by the remote server.
458 /// The network operation failed because it was not connected yet.
460 /// The operation failed because a pipe was closed.
462 /// A file already existed with that name.
464 /// No file exists at that location.
466 /// The path did not specify the type of file that this operation required. For example,
467 /// attempting to copy a directory with the `fs::copy()` operation will fail with this error.
468 MismatchedFileTypeForOperation,
469 /// The operation temporarily failed (for example, because a signal was received), and retrying
472 /// No I/O functionality is available for this task.
474 /// A parameter was incorrect in a way that caused an I/O error not part of this list.
476 /// The I/O operation's timeout expired, causing it to be canceled.
478 /// This write operation failed to write all of its data.
480 /// Normally the write() method on a Writer guarantees that all of its data
481 /// has been written, but some operations may be terminated after only
482 /// partially writing some data. An example of this is a timed out write
483 /// which successfully wrote a known number of bytes, but bailed out after
486 /// The payload contained as part of this variant is the number of bytes
487 /// which are known to have been successfully written.
489 /// The Reader returned 0 bytes from `read()` too many times.
493 /// A trait that lets you add a `detail` to an IoError easily
494 trait UpdateIoError<T> {
495 /// Returns an IoError with updated description and detail
496 fn update_err(self, desc: &'static str, detail: |&IoError| -> String) -> Self;
498 /// Returns an IoError with updated detail
499 fn update_detail(self, detail: |&IoError| -> String) -> Self;
501 /// Returns an IoError with update description
502 fn update_desc(self, desc: &'static str) -> Self;
505 impl<T> UpdateIoError<T> for IoResult<T> {
506 fn update_err(self, desc: &'static str, detail: |&IoError| -> String) -> IoResult<T> {
507 self.map_err(|mut e| {
508 let detail = detail(&e);
510 e.detail = Some(detail);
515 fn update_detail(self, detail: |&IoError| -> String) -> IoResult<T> {
516 self.map_err(|mut e| { e.detail = Some(detail(&e)); e })
519 fn update_desc(self, desc: &'static str) -> IoResult<T> {
520 self.map_err(|mut e| { e.desc = desc; e })
524 static NO_PROGRESS_LIMIT: uint = 1000;
526 /// A trait for objects which are byte-oriented streams. Readers are defined by
527 /// one method, `read`. This function will block until data is available,
528 /// filling in the provided buffer with any data read.
530 /// Readers are intended to be composable with one another. Many objects
531 /// throughout the I/O and related libraries take and provide types which
532 /// implement the `Reader` trait.
535 // Only method which need to get implemented for this trait
537 /// Read bytes, up to the length of `buf` and place them in `buf`.
538 /// Returns the number of bytes read. The number of bytes read may
539 /// be less than the number requested, even 0. Returns `Err` on EOF.
543 /// If an error occurs during this I/O operation, then it is returned as
544 /// `Err(IoError)`. Note that end-of-file is considered an error, and can be
545 /// inspected for in the error's `kind` field. Also note that reading 0
546 /// bytes is not considered an error in all circumstances
548 /// # Implementation Note
550 /// When implementing this method on a new Reader, you are strongly encouraged
551 /// not to return 0 if you can avoid it.
552 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint>;
554 // Convenient helper methods based on the above methods
556 /// Reads at least `min` bytes and places them in `buf`.
557 /// Returns the number of bytes read.
559 /// This will continue to call `read` until at least `min` bytes have been
560 /// read. If `read` returns 0 too many times, `NoProgress` will be
565 /// If an error occurs at any point, that error is returned, and no further
567 fn read_at_least(&mut self, min: uint, buf: &mut [u8]) -> IoResult<uint> {
570 detail: Some(String::from_str("the buffer is too short")),
571 ..standard_error(InvalidInput)
578 match self.read(buf[mut read..]) {
581 if zeroes >= NO_PROGRESS_LIMIT {
582 return Err(standard_error(NoProgress));
589 err@Err(_) => return err
596 /// Reads a single byte. Returns `Err` on EOF.
597 fn read_byte(&mut self) -> IoResult<u8> {
599 try!(self.read_at_least(1, buf));
603 /// Reads up to `len` bytes and appends them to a vector.
604 /// Returns the number of bytes read. The number of bytes read may be
605 /// less than the number requested, even 0. Returns Err on EOF.
609 /// If an error occurs during this I/O operation, then it is returned
610 /// as `Err(IoError)`. See `read()` for more details.
611 fn push(&mut self, len: uint, buf: &mut Vec<u8>) -> IoResult<uint> {
612 let start_len = buf.len();
613 buf.reserve_additional(len);
616 let s = unsafe { slice_vec_capacity(buf, start_len, start_len + len) };
619 unsafe { buf.set_len(start_len + n) };
623 /// Reads at least `min` bytes, but no more than `len`, and appends them to
625 /// Returns the number of bytes read.
627 /// This will continue to call `read` until at least `min` bytes have been
628 /// read. If `read` returns 0 too many times, `NoProgress` will be
633 /// If an error occurs at any point, that error is returned, and no further
635 fn push_at_least(&mut self, min: uint, len: uint, buf: &mut Vec<u8>) -> IoResult<uint> {
638 detail: Some(String::from_str("the buffer is too short")),
639 ..standard_error(InvalidInput)
643 let start_len = buf.len();
644 buf.reserve_additional(len);
646 // we can't just use self.read_at_least(min, slice) because we need to push
647 // successful reads onto the vector before any returned errors.
652 let s = unsafe { slice_vec_capacity(buf, start_len + read, start_len + len) };
653 try!(self.read_at_least(1, s))
655 unsafe { buf.set_len(start_len + read) };
660 /// Reads exactly `len` bytes and gives you back a new vector of length
665 /// Fails with the same conditions as `read`. Additionally returns error
666 /// on EOF. Note that if an error is returned, then some number of bytes may
667 /// have already been consumed from the underlying reader, and they are lost
668 /// (not returned as part of the error). If this is unacceptable, then it is
669 /// recommended to use the `push_at_least` or `read` methods.
670 fn read_exact(&mut self, len: uint) -> IoResult<Vec<u8>> {
671 let mut buf = Vec::with_capacity(len);
672 match self.push_at_least(len, len, &mut buf) {
678 /// Reads all remaining bytes from the stream.
682 /// Returns any non-EOF error immediately. Previously read bytes are
683 /// discarded when an error is returned.
685 /// When EOF is encountered, all bytes read up to that point are returned.
686 fn read_to_end(&mut self) -> IoResult<Vec<u8>> {
687 let mut buf = Vec::with_capacity(DEFAULT_BUF_SIZE);
689 match self.push_at_least(1, DEFAULT_BUF_SIZE, &mut buf) {
691 Err(ref e) if e.kind == EndOfFile => break,
692 Err(e) => return Err(e)
698 /// Reads all of the remaining bytes of this stream, interpreting them as a
699 /// UTF-8 encoded stream. The corresponding string is returned.
703 /// This function returns all of the same errors as `read_to_end` with an
704 /// additional error if the reader's contents are not a valid sequence of
706 fn read_to_string(&mut self) -> IoResult<String> {
707 self.read_to_end().and_then(|s| {
708 match String::from_utf8(s) {
710 Err(_) => Err(standard_error(InvalidInput)),
715 /// Create an iterator that reads a single byte on
716 /// each iteration, until EOF.
720 /// Any error other than `EndOfFile` that is produced by the underlying Reader
721 /// is returned by the iterator and should be handled by the caller.
722 fn bytes<'r>(&'r mut self) -> extensions::Bytes<'r, Self> {
723 extensions::Bytes::new(self)
726 // Byte conversion helpers
728 /// Reads `n` little-endian unsigned integer bytes.
730 /// `n` must be between 1 and 8, inclusive.
731 fn read_le_uint_n(&mut self, nbytes: uint) -> IoResult<u64> {
732 assert!(nbytes > 0 && nbytes <= 8);
738 val += (try!(self.read_u8()) as u64) << pos;
745 /// Reads `n` little-endian signed integer bytes.
747 /// `n` must be between 1 and 8, inclusive.
748 fn read_le_int_n(&mut self, nbytes: uint) -> IoResult<i64> {
749 self.read_le_uint_n(nbytes).map(|i| extend_sign(i, nbytes))
752 /// Reads `n` big-endian unsigned integer bytes.
754 /// `n` must be between 1 and 8, inclusive.
755 fn read_be_uint_n(&mut self, nbytes: uint) -> IoResult<u64> {
756 assert!(nbytes > 0 && nbytes <= 8);
762 val += (try!(self.read_u8()) as u64) << i * 8;
767 /// Reads `n` big-endian signed integer bytes.
769 /// `n` must be between 1 and 8, inclusive.
770 fn read_be_int_n(&mut self, nbytes: uint) -> IoResult<i64> {
771 self.read_be_uint_n(nbytes).map(|i| extend_sign(i, nbytes))
774 /// Reads a little-endian unsigned integer.
776 /// The number of bytes returned is system-dependent.
777 fn read_le_uint(&mut self) -> IoResult<uint> {
778 self.read_le_uint_n(uint::BYTES).map(|i| i as uint)
781 /// Reads a little-endian integer.
783 /// The number of bytes returned is system-dependent.
784 fn read_le_int(&mut self) -> IoResult<int> {
785 self.read_le_int_n(int::BYTES).map(|i| i as int)
788 /// Reads a big-endian unsigned integer.
790 /// The number of bytes returned is system-dependent.
791 fn read_be_uint(&mut self) -> IoResult<uint> {
792 self.read_be_uint_n(uint::BYTES).map(|i| i as uint)
795 /// Reads a big-endian integer.
797 /// The number of bytes returned is system-dependent.
798 fn read_be_int(&mut self) -> IoResult<int> {
799 self.read_be_int_n(int::BYTES).map(|i| i as int)
802 /// Reads a big-endian `u64`.
804 /// `u64`s are 8 bytes long.
805 fn read_be_u64(&mut self) -> IoResult<u64> {
806 self.read_be_uint_n(8)
809 /// Reads a big-endian `u32`.
811 /// `u32`s are 4 bytes long.
812 fn read_be_u32(&mut self) -> IoResult<u32> {
813 self.read_be_uint_n(4).map(|i| i as u32)
816 /// Reads a big-endian `u16`.
818 /// `u16`s are 2 bytes long.
819 fn read_be_u16(&mut self) -> IoResult<u16> {
820 self.read_be_uint_n(2).map(|i| i as u16)
823 /// Reads a big-endian `i64`.
825 /// `i64`s are 8 bytes long.
826 fn read_be_i64(&mut self) -> IoResult<i64> {
827 self.read_be_int_n(8)
830 /// Reads a big-endian `i32`.
832 /// `i32`s are 4 bytes long.
833 fn read_be_i32(&mut self) -> IoResult<i32> {
834 self.read_be_int_n(4).map(|i| i as i32)
837 /// Reads a big-endian `i16`.
839 /// `i16`s are 2 bytes long.
840 fn read_be_i16(&mut self) -> IoResult<i16> {
841 self.read_be_int_n(2).map(|i| i as i16)
844 /// Reads a big-endian `f64`.
846 /// `f64`s are 8 byte, IEEE754 double-precision floating point numbers.
847 fn read_be_f64(&mut self) -> IoResult<f64> {
848 self.read_be_u64().map(|i| unsafe {
849 transmute::<u64, f64>(i)
853 /// Reads a big-endian `f32`.
855 /// `f32`s are 4 byte, IEEE754 single-precision floating point numbers.
856 fn read_be_f32(&mut self) -> IoResult<f32> {
857 self.read_be_u32().map(|i| unsafe {
858 transmute::<u32, f32>(i)
862 /// Reads a little-endian `u64`.
864 /// `u64`s are 8 bytes long.
865 fn read_le_u64(&mut self) -> IoResult<u64> {
866 self.read_le_uint_n(8)
869 /// Reads a little-endian `u32`.
871 /// `u32`s are 4 bytes long.
872 fn read_le_u32(&mut self) -> IoResult<u32> {
873 self.read_le_uint_n(4).map(|i| i as u32)
876 /// Reads a little-endian `u16`.
878 /// `u16`s are 2 bytes long.
879 fn read_le_u16(&mut self) -> IoResult<u16> {
880 self.read_le_uint_n(2).map(|i| i as u16)
883 /// Reads a little-endian `i64`.
885 /// `i64`s are 8 bytes long.
886 fn read_le_i64(&mut self) -> IoResult<i64> {
887 self.read_le_int_n(8)
890 /// Reads a little-endian `i32`.
892 /// `i32`s are 4 bytes long.
893 fn read_le_i32(&mut self) -> IoResult<i32> {
894 self.read_le_int_n(4).map(|i| i as i32)
897 /// Reads a little-endian `i16`.
899 /// `i16`s are 2 bytes long.
900 fn read_le_i16(&mut self) -> IoResult<i16> {
901 self.read_le_int_n(2).map(|i| i as i16)
904 /// Reads a little-endian `f64`.
906 /// `f64`s are 8 byte, IEEE754 double-precision floating point numbers.
907 fn read_le_f64(&mut self) -> IoResult<f64> {
908 self.read_le_u64().map(|i| unsafe {
909 transmute::<u64, f64>(i)
913 /// Reads a little-endian `f32`.
915 /// `f32`s are 4 byte, IEEE754 single-precision floating point numbers.
916 fn read_le_f32(&mut self) -> IoResult<f32> {
917 self.read_le_u32().map(|i| unsafe {
918 transmute::<u32, f32>(i)
924 /// `u8`s are 1 byte.
925 fn read_u8(&mut self) -> IoResult<u8> {
931 /// `i8`s are 1 byte.
932 fn read_i8(&mut self) -> IoResult<i8> {
933 self.read_byte().map(|i| i as i8)
936 /// Creates a wrapper around a mutable reference to the reader.
938 /// This is useful to allow applying adaptors while still
939 /// retaining ownership of the original value.
940 fn by_ref<'a>(&'a mut self) -> RefReader<'a, Self> {
941 RefReader { inner: self }
945 impl<'a> Reader for Box<Reader+'a> {
946 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> {
947 let reader: &mut Reader = &mut **self;
952 impl<'a> Reader for &'a mut Reader+'a {
953 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> { (*self).read(buf) }
956 /// Returns a slice of `v` between `start` and `end`.
958 /// Similar to `slice()` except this function only bounds the slice on the
959 /// capacity of `v`, not the length.
963 /// Fails when `start` or `end` point outside the capacity of `v`, or when
965 // Private function here because we aren't sure if we want to expose this as
966 // API yet. If so, it should be a method on Vec.
967 unsafe fn slice_vec_capacity<'a, T>(v: &'a mut Vec<T>, start: uint, end: uint) -> &'a mut [T] {
971 assert!(start <= end);
972 assert!(end <= v.capacity());
974 data: v.as_ptr().offset(start as int),
979 /// A `RefReader` is a struct implementing `Reader` which contains a reference
980 /// to another reader. This is often useful when composing streams.
986 /// # fn process_input<R: Reader>(r: R) {}
989 /// use std::io::util::LimitReader;
991 /// let mut stream = io::stdin();
993 /// // Only allow the function to process at most one kilobyte of input
995 /// let stream = LimitReader::new(stream.by_ref(), 1024);
996 /// process_input(stream);
999 /// // 'stream' is still available for use here
1003 pub struct RefReader<'a, R:'a> {
1004 /// The underlying reader which this is referencing
1008 impl<'a, R: Reader> Reader for RefReader<'a, R> {
1009 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> { self.inner.read(buf) }
1012 impl<'a, R: Buffer> Buffer for RefReader<'a, R> {
1013 fn fill_buf<'a>(&'a mut self) -> IoResult<&'a [u8]> { self.inner.fill_buf() }
1014 fn consume(&mut self, amt: uint) { self.inner.consume(amt) }
1017 fn extend_sign(val: u64, nbytes: uint) -> i64 {
1018 let shift = (8 - nbytes) * 8;
1019 (val << shift) as i64 >> shift
1022 /// A trait for objects which are byte-oriented streams. Writers are defined by
1023 /// one method, `write`. This function will block until the provided buffer of
1024 /// bytes has been entirely written, and it will return any failures which occur.
1026 /// Another commonly overridden method is the `flush` method for writers such as
1027 /// buffered writers.
1029 /// Writers are intended to be composable with one another. Many objects
1030 /// throughout the I/O and related libraries take and provide types which
1031 /// implement the `Writer` trait.
1033 /// Write the entirety of a given buffer
1037 /// If an error happens during the I/O operation, the error is returned as
1038 /// `Err`. Note that it is considered an error if the entire buffer could
1039 /// not be written, and if an error is returned then it is unknown how much
1040 /// data (if any) was actually written.
1041 fn write(&mut self, buf: &[u8]) -> IoResult<()>;
1043 /// Flush this output stream, ensuring that all intermediately buffered
1044 /// contents reach their destination.
1046 /// This is by default a no-op and implementers of the `Writer` trait should
1047 /// decide whether their stream needs to be buffered or not.
1048 fn flush(&mut self) -> IoResult<()> { Ok(()) }
1050 /// Writes a formatted string into this writer, returning any error
1053 /// This method is primarily used to interface with the `format_args!`
1054 /// macro, but it is rare that this should explicitly be called. The
1055 /// `write!` macro should be favored to invoke this method instead.
1059 /// This function will return any I/O error reported while formatting.
1060 fn write_fmt(&mut self, fmt: &fmt::Arguments) -> IoResult<()> {
1061 // Create a shim which translates a Writer to a FormatWriter and saves
1062 // off I/O errors. instead of discarding them
1063 struct Adaptor<'a, T:'a> {
1065 error: IoResult<()>,
1068 impl<'a, T: Writer> fmt::FormatWriter for Adaptor<'a, T> {
1069 fn write(&mut self, bytes: &[u8]) -> fmt::Result {
1070 match self.inner.write(bytes) {
1073 self.error = Err(e);
1074 Err(fmt::WriteError)
1080 let mut output = Adaptor { inner: self, error: Ok(()) };
1081 match fmt::write(&mut output, fmt) {
1083 Err(..) => output.error
1087 /// Write a rust string into this sink.
1089 /// The bytes written will be the UTF-8 encoded version of the input string.
1090 /// If other encodings are desired, it is recommended to compose this stream
1091 /// with another performing the conversion, or to use `write` with a
1092 /// converted byte-array instead.
1094 fn write_str(&mut self, s: &str) -> IoResult<()> {
1095 self.write(s.as_bytes())
1098 /// Writes a string into this sink, and then writes a literal newline (`\n`)
1099 /// byte afterwards. Note that the writing of the newline is *not* atomic in
1100 /// the sense that the call to `write` is invoked twice (once with the
1101 /// string and once with a newline character).
1103 /// If other encodings or line ending flavors are desired, it is recommended
1104 /// that the `write` method is used specifically instead.
1106 fn write_line(&mut self, s: &str) -> IoResult<()> {
1107 self.write_str(s).and_then(|()| self.write([b'\n']))
1110 /// Write a single char, encoded as UTF-8.
1112 fn write_char(&mut self, c: char) -> IoResult<()> {
1113 let mut buf = [0u8, ..4];
1114 let n = c.encode_utf8(buf[mut]).unwrap_or(0);
1115 self.write(buf[..n])
1118 /// Write the result of passing n through `int::to_str_bytes`.
1120 fn write_int(&mut self, n: int) -> IoResult<()> {
1121 write!(self, "{:d}", n)
1124 /// Write the result of passing n through `uint::to_str_bytes`.
1126 fn write_uint(&mut self, n: uint) -> IoResult<()> {
1127 write!(self, "{:u}", n)
1130 /// Write a little-endian uint (number of bytes depends on system).
1132 fn write_le_uint(&mut self, n: uint) -> IoResult<()> {
1133 extensions::u64_to_le_bytes(n as u64, uint::BYTES, |v| self.write(v))
1136 /// Write a little-endian int (number of bytes depends on system).
1138 fn write_le_int(&mut self, n: int) -> IoResult<()> {
1139 extensions::u64_to_le_bytes(n as u64, int::BYTES, |v| self.write(v))
1142 /// Write a big-endian uint (number of bytes depends on system).
1144 fn write_be_uint(&mut self, n: uint) -> IoResult<()> {
1145 extensions::u64_to_be_bytes(n as u64, uint::BYTES, |v| self.write(v))
1148 /// Write a big-endian int (number of bytes depends on system).
1150 fn write_be_int(&mut self, n: int) -> IoResult<()> {
1151 extensions::u64_to_be_bytes(n as u64, int::BYTES, |v| self.write(v))
1154 /// Write a big-endian u64 (8 bytes).
1156 fn write_be_u64(&mut self, n: u64) -> IoResult<()> {
1157 extensions::u64_to_be_bytes(n, 8u, |v| self.write(v))
1160 /// Write a big-endian u32 (4 bytes).
1162 fn write_be_u32(&mut self, n: u32) -> IoResult<()> {
1163 extensions::u64_to_be_bytes(n as u64, 4u, |v| self.write(v))
1166 /// Write a big-endian u16 (2 bytes).
1168 fn write_be_u16(&mut self, n: u16) -> IoResult<()> {
1169 extensions::u64_to_be_bytes(n as u64, 2u, |v| self.write(v))
1172 /// Write a big-endian i64 (8 bytes).
1174 fn write_be_i64(&mut self, n: i64) -> IoResult<()> {
1175 extensions::u64_to_be_bytes(n as u64, 8u, |v| self.write(v))
1178 /// Write a big-endian i32 (4 bytes).
1180 fn write_be_i32(&mut self, n: i32) -> IoResult<()> {
1181 extensions::u64_to_be_bytes(n as u64, 4u, |v| self.write(v))
1184 /// Write a big-endian i16 (2 bytes).
1186 fn write_be_i16(&mut self, n: i16) -> IoResult<()> {
1187 extensions::u64_to_be_bytes(n as u64, 2u, |v| self.write(v))
1190 /// Write a big-endian IEEE754 double-precision floating-point (8 bytes).
1192 fn write_be_f64(&mut self, f: f64) -> IoResult<()> {
1194 self.write_be_u64(transmute(f))
1198 /// Write a big-endian IEEE754 single-precision floating-point (4 bytes).
1200 fn write_be_f32(&mut self, f: f32) -> IoResult<()> {
1202 self.write_be_u32(transmute(f))
1206 /// Write a little-endian u64 (8 bytes).
1208 fn write_le_u64(&mut self, n: u64) -> IoResult<()> {
1209 extensions::u64_to_le_bytes(n, 8u, |v| self.write(v))
1212 /// Write a little-endian u32 (4 bytes).
1214 fn write_le_u32(&mut self, n: u32) -> IoResult<()> {
1215 extensions::u64_to_le_bytes(n as u64, 4u, |v| self.write(v))
1218 /// Write a little-endian u16 (2 bytes).
1220 fn write_le_u16(&mut self, n: u16) -> IoResult<()> {
1221 extensions::u64_to_le_bytes(n as u64, 2u, |v| self.write(v))
1224 /// Write a little-endian i64 (8 bytes).
1226 fn write_le_i64(&mut self, n: i64) -> IoResult<()> {
1227 extensions::u64_to_le_bytes(n as u64, 8u, |v| self.write(v))
1230 /// Write a little-endian i32 (4 bytes).
1232 fn write_le_i32(&mut self, n: i32) -> IoResult<()> {
1233 extensions::u64_to_le_bytes(n as u64, 4u, |v| self.write(v))
1236 /// Write a little-endian i16 (2 bytes).
1238 fn write_le_i16(&mut self, n: i16) -> IoResult<()> {
1239 extensions::u64_to_le_bytes(n as u64, 2u, |v| self.write(v))
1242 /// Write a little-endian IEEE754 double-precision floating-point
1245 fn write_le_f64(&mut self, f: f64) -> IoResult<()> {
1247 self.write_le_u64(transmute(f))
1251 /// Write a little-endian IEEE754 single-precision floating-point
1254 fn write_le_f32(&mut self, f: f32) -> IoResult<()> {
1256 self.write_le_u32(transmute(f))
1260 /// Write a u8 (1 byte).
1262 fn write_u8(&mut self, n: u8) -> IoResult<()> {
1266 /// Write an i8 (1 byte).
1268 fn write_i8(&mut self, n: i8) -> IoResult<()> {
1269 self.write([n as u8])
1272 /// Creates a wrapper around a mutable reference to the writer.
1274 /// This is useful to allow applying wrappers while still
1275 /// retaining ownership of the original value.
1277 fn by_ref<'a>(&'a mut self) -> RefWriter<'a, Self> {
1278 RefWriter { inner: self }
1282 impl<'a> Writer for Box<Writer+'a> {
1284 fn write(&mut self, buf: &[u8]) -> IoResult<()> {
1285 (&mut **self).write(buf)
1289 fn flush(&mut self) -> IoResult<()> {
1290 (&mut **self).flush()
1294 impl<'a> Writer for &'a mut Writer+'a {
1296 fn write(&mut self, buf: &[u8]) -> IoResult<()> { (**self).write(buf) }
1299 fn flush(&mut self) -> IoResult<()> { (**self).flush() }
1302 /// A `RefWriter` is a struct implementing `Writer` which contains a reference
1303 /// to another writer. This is often useful when composing streams.
1309 /// # fn process_input<R: Reader>(r: R) {}
1311 /// use std::io::util::TeeReader;
1312 /// use std::io::{stdin, MemWriter};
1314 /// let mut output = MemWriter::new();
1317 /// // Don't give ownership of 'output' to the 'tee'. Instead we keep a
1318 /// // handle to it in the outer scope
1319 /// let mut tee = TeeReader::new(stdin(), output.by_ref());
1320 /// process_input(tee);
1323 /// println!("input processed: {}", output.unwrap());
1326 pub struct RefWriter<'a, W:'a> {
1327 /// The underlying writer which this is referencing
1331 impl<'a, W: Writer> Writer for RefWriter<'a, W> {
1333 fn write(&mut self, buf: &[u8]) -> IoResult<()> { self.inner.write(buf) }
1336 fn flush(&mut self) -> IoResult<()> { self.inner.flush() }
1340 /// A Stream is a readable and a writable object. Data written is typically
1341 /// received by the object which reads receive data from.
1342 pub trait Stream: Reader + Writer { }
1344 impl<T: Reader + Writer> Stream for T {}
1346 /// An iterator that reads a line on each iteration,
1347 /// until `.read_line()` encounters `EndOfFile`.
1349 /// # Notes about the Iteration Protocol
1351 /// The `Lines` may yield `None` and thus terminate
1352 /// an iteration, but continue to yield elements if iteration
1353 /// is attempted again.
1357 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1358 /// is returned by the iterator and should be handled by the caller.
1359 pub struct Lines<'r, T:'r> {
1363 impl<'r, T: Buffer> Iterator<IoResult<String>> for Lines<'r, T> {
1364 fn next(&mut self) -> Option<IoResult<String>> {
1365 match self.buffer.read_line() {
1366 Ok(x) => Some(Ok(x)),
1367 Err(IoError { kind: EndOfFile, ..}) => None,
1368 Err(y) => Some(Err(y))
1373 /// An iterator that reads a utf8-encoded character on each iteration,
1374 /// until `.read_char()` encounters `EndOfFile`.
1376 /// # Notes about the Iteration Protocol
1378 /// The `Chars` may yield `None` and thus terminate
1379 /// an iteration, but continue to yield elements if iteration
1380 /// is attempted again.
1384 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1385 /// is returned by the iterator and should be handled by the caller.
1386 pub struct Chars<'r, T:'r> {
1390 impl<'r, T: Buffer> Iterator<IoResult<char>> for Chars<'r, T> {
1391 fn next(&mut self) -> Option<IoResult<char>> {
1392 match self.buffer.read_char() {
1393 Ok(x) => Some(Ok(x)),
1394 Err(IoError { kind: EndOfFile, ..}) => None,
1395 Err(y) => Some(Err(y))
1400 /// A Buffer is a type of reader which has some form of internal buffering to
1401 /// allow certain kinds of reading operations to be more optimized than others.
1402 /// This type extends the `Reader` trait with a few methods that are not
1403 /// possible to reasonably implement with purely a read interface.
1404 pub trait Buffer: Reader {
1405 /// Fills the internal buffer of this object, returning the buffer contents.
1406 /// Note that none of the contents will be "read" in the sense that later
1407 /// calling `read` may return the same contents.
1409 /// The `consume` function must be called with the number of bytes that are
1410 /// consumed from this buffer returned to ensure that the bytes are never
1415 /// This function will return an I/O error if the underlying reader was
1416 /// read, but returned an error. Note that it is not an error to return a
1417 /// 0-length buffer.
1418 fn fill_buf<'a>(&'a mut self) -> IoResult<&'a [u8]>;
1420 /// Tells this buffer that `amt` bytes have been consumed from the buffer,
1421 /// so they should no longer be returned in calls to `read`.
1422 fn consume(&mut self, amt: uint);
1424 /// Reads the next line of input, interpreted as a sequence of UTF-8
1425 /// encoded Unicode codepoints. If a newline is encountered, then the
1426 /// newline is contained in the returned string.
1433 /// let mut reader = io::stdin();
1434 /// let input = reader.read_line().ok().unwrap_or("nothing".to_string());
1439 /// This function has the same error semantics as `read_until`:
1441 /// * All non-EOF errors will be returned immediately
1442 /// * If an error is returned previously consumed bytes are lost
1443 /// * EOF is only returned if no bytes have been read
1444 /// * Reach EOF may mean that the delimiter is not present in the return
1447 /// Additionally, this function can fail if the line of input read is not a
1448 /// valid UTF-8 sequence of bytes.
1449 fn read_line(&mut self) -> IoResult<String> {
1450 self.read_until(b'\n').and_then(|line|
1451 match String::from_utf8(line) {
1453 Err(_) => Err(standard_error(InvalidInput)),
1458 /// Create an iterator that reads a line on each iteration until EOF.
1462 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1463 /// is returned by the iterator and should be handled by the caller.
1464 fn lines<'r>(&'r mut self) -> Lines<'r, Self> {
1465 Lines { buffer: self }
1468 /// Reads a sequence of bytes leading up to a specified delimiter. Once the
1469 /// specified byte is encountered, reading ceases and the bytes up to and
1470 /// including the delimiter are returned.
1474 /// If any I/O error is encountered other than EOF, the error is immediately
1475 /// returned. Note that this may discard bytes which have already been read,
1476 /// and those bytes will *not* be returned. It is recommended to use other
1477 /// methods if this case is worrying.
1479 /// If EOF is encountered, then this function will return EOF if 0 bytes
1480 /// have been read, otherwise the pending byte buffer is returned. This
1481 /// is the reason that the byte buffer returned may not always contain the
1483 fn read_until(&mut self, byte: u8) -> IoResult<Vec<u8>> {
1484 let mut res = Vec::new();
1489 let available = match self.fill_buf() {
1491 Err(ref e) if res.len() > 0 && e.kind == EndOfFile => {
1495 Err(e) => return Err(e)
1497 match available.iter().position(|&b| b == byte) {
1499 res.push_all(available[..i + 1]);
1504 res.push_all(available);
1505 used = available.len();
1515 /// Reads the next utf8-encoded character from the underlying stream.
1519 /// If an I/O error occurs, or EOF, then this function will return `Err`.
1520 /// This function will also return error if the stream does not contain a
1521 /// valid utf-8 encoded codepoint as the next few bytes in the stream.
1522 fn read_char(&mut self) -> IoResult<char> {
1523 let first_byte = try!(self.read_byte());
1524 let width = str::utf8_char_width(first_byte);
1525 if width == 1 { return Ok(first_byte as char) }
1526 if width == 0 { return Err(standard_error(InvalidInput)) } // not utf8
1527 let mut buf = [first_byte, 0, 0, 0];
1530 while start < width {
1531 match try!(self.read(buf[mut start..width])) {
1532 n if n == width - start => break,
1533 n if n < width - start => { start += n; }
1534 _ => return Err(standard_error(InvalidInput)),
1538 match str::from_utf8(buf[..width]) {
1539 Some(s) => Ok(s.char_at(0)),
1540 None => Err(standard_error(InvalidInput))
1544 /// Create an iterator that reads a utf8-encoded character on each iteration
1549 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1550 /// is returned by the iterator and should be handled by the caller.
1551 fn chars<'r>(&'r mut self) -> Chars<'r, Self> {
1552 Chars { buffer: self }
1556 /// When seeking, the resulting cursor is offset from a base by the offset given
1557 /// to the `seek` function. The base used is specified by this enumeration.
1558 pub enum SeekStyle {
1559 /// Seek from the beginning of the stream
1561 /// Seek from the end of the stream
1563 /// Seek from the current position
1567 /// An object implementing `Seek` internally has some form of cursor which can
1568 /// be moved within a stream of bytes. The stream typically has a fixed size,
1569 /// allowing seeking relative to either end.
1571 /// Return position of file cursor in the stream
1572 fn tell(&self) -> IoResult<u64>;
1574 /// Seek to an offset in a stream
1576 /// A successful seek clears the EOF indicator. Seeking beyond EOF is
1577 /// allowed, but seeking before position 0 is not allowed.
1581 /// * Seeking to a negative offset is considered an error
1582 /// * Seeking past the end of the stream does not modify the underlying
1583 /// stream, but the next write may cause the previous data to be filled in
1584 /// with a bit pattern.
1585 fn seek(&mut self, pos: i64, style: SeekStyle) -> IoResult<()>;
1588 /// A listener is a value that can consume itself to start listening for
1591 /// Doing so produces some sort of Acceptor.
1592 pub trait Listener<T, A: Acceptor<T>> {
1593 /// Spin up the listener and start queuing incoming connections
1597 /// Returns `Err` if this listener could not be bound to listen for
1598 /// connections. In all cases, this listener is consumed.
1599 fn listen(self) -> IoResult<A>;
1602 /// An acceptor is a value that presents incoming connections
1603 pub trait Acceptor<T> {
1604 /// Wait for and accept an incoming connection
1608 /// Returns `Err` if an I/O error is encountered.
1609 fn accept(&mut self) -> IoResult<T>;
1611 /// Create an iterator over incoming connection attempts.
1613 /// Note that I/O errors will be yielded by the iterator itself.
1614 fn incoming<'r>(&'r mut self) -> IncomingConnections<'r, Self> {
1615 IncomingConnections { inc: self }
1619 /// An infinite iterator over incoming connection attempts.
1620 /// Calling `next` will block the task until a connection is attempted.
1622 /// Since connection attempts can continue forever, this iterator always returns
1623 /// `Some`. The `Some` contains the `IoResult` representing whether the
1624 /// connection attempt was successful. A successful connection will be wrapped
1625 /// in `Ok`. A failed connection is represented as an `Err`.
1626 pub struct IncomingConnections<'a, A:'a> {
1630 impl<'a, T, A: Acceptor<T>> Iterator<IoResult<T>> for IncomingConnections<'a, A> {
1631 fn next(&mut self) -> Option<IoResult<T>> {
1632 Some(self.inc.accept())
1636 /// Creates a standard error for a commonly used flavor of error. The `detail`
1637 /// field of the returned error will always be `None`.
1644 /// let eof = io::standard_error(io::EndOfFile);
1645 /// let einval = io::standard_error(io::InvalidInput);
1647 pub fn standard_error(kind: IoErrorKind) -> IoError {
1648 let desc = match kind {
1649 EndOfFile => "end of file",
1650 IoUnavailable => "I/O is unavailable",
1651 InvalidInput => "invalid input",
1652 OtherIoError => "unknown I/O error",
1653 FileNotFound => "file not found",
1654 PermissionDenied => "permission denied",
1655 ConnectionFailed => "connection failed",
1656 Closed => "stream is closed",
1657 ConnectionRefused => "connection refused",
1658 ConnectionReset => "connection reset",
1659 ConnectionAborted => "connection aborted",
1660 NotConnected => "not connected",
1661 BrokenPipe => "broken pipe",
1662 PathAlreadyExists => "file already exists",
1663 PathDoesntExist => "no such file",
1664 MismatchedFileTypeForOperation => "mismatched file type",
1665 ResourceUnavailable => "resource unavailable",
1666 TimedOut => "operation timed out",
1667 ShortWrite(..) => "short write",
1668 NoProgress => "no progress",
1677 /// A mode specifies how a file should be opened or created. These modes are
1678 /// passed to `File::open_mode` and are used to control where the file is
1679 /// positioned when it is initially opened.
1681 /// Opens a file positioned at the beginning.
1683 /// Opens a file positioned at EOF.
1685 /// Opens a file, truncating it if it already exists.
1689 /// Access permissions with which the file should be opened. `File`s
1690 /// opened with `Read` will return an error if written to.
1691 pub enum FileAccess {
1692 /// Read-only access, requests to write will result in an error
1694 /// Write-only access, requests to read will result in an error
1696 /// Read-write access, no requests are denied by default
1700 /// Different kinds of files which can be identified by a call to stat
1701 #[deriving(PartialEq, Show, Hash)]
1703 /// This is a normal file, corresponding to `S_IFREG`
1706 /// This file is a directory, corresponding to `S_IFDIR`
1709 /// This file is a named pipe, corresponding to `S_IFIFO`
1712 /// This file is a block device, corresponding to `S_IFBLK`
1715 /// This file is a symbolic link to another file, corresponding to `S_IFLNK`
1718 /// The type of this file is not recognized as one of the other categories
1722 /// A structure used to describe metadata information about a file. This
1723 /// structure is created through the `stat` method on a `Path`.
1728 /// # use std::io::fs::PathExtensions;
1731 /// let info = match Path::new("foo.txt").stat() {
1732 /// Ok(stat) => stat,
1733 /// Err(e) => fail!("couldn't read foo.txt: {}", e),
1736 /// println!("byte size: {}", info.size);
1740 pub struct FileStat {
1741 /// The size of the file, in bytes
1743 /// The kind of file this path points to (directory, file, pipe, etc.)
1745 /// The file permissions currently on the file
1746 pub perm: FilePermission,
1748 // FIXME(#10301): These time fields are pretty useless without an actual
1749 // time representation, what are the milliseconds relative
1752 /// The time that the file was created at, in platform-dependent
1755 /// The time that this file was last modified, in platform-dependent
1758 /// The time that this file was last accessed, in platform-dependent
1762 /// Information returned by stat() which is not guaranteed to be
1763 /// platform-independent. This information may be useful on some platforms,
1764 /// but it may have different meanings or no meaning at all on other
1767 /// Usage of this field is discouraged, but if access is desired then the
1768 /// fields are located here.
1770 pub unstable: UnstableFileStat,
1773 /// This structure represents all of the possible information which can be
1774 /// returned from a `stat` syscall which is not contained in the `FileStat`
1775 /// structure. This information is not necessarily platform independent, and may
1776 /// have different meanings or no meaning at all on some platforms.
1779 pub struct UnstableFileStat {
1780 /// The ID of the device containing the file.
1782 /// The file serial number.
1786 /// The number of hard links to this file.
1788 /// The user ID of the file.
1790 /// The group ID of the file.
1792 /// The optimal block size for I/O.
1794 /// The blocks allocated for this file.
1796 /// User-defined flags for the file.
1798 /// The file generation number.
1803 #[doc = "A set of permissions for a file or directory is represented"]
1804 #[doc = "by a set of flags which are or'd together."]
1805 flags FilePermission: u32 {
1806 const USER_READ = 0o400,
1807 const USER_WRITE = 0o200,
1808 const USER_EXECUTE = 0o100,
1809 const GROUP_READ = 0o040,
1810 const GROUP_WRITE = 0o020,
1811 const GROUP_EXECUTE = 0o010,
1812 const OTHER_READ = 0o004,
1813 const OTHER_WRITE = 0o002,
1814 const OTHER_EXECUTE = 0o001,
1816 const USER_RWX = USER_READ.bits | USER_WRITE.bits | USER_EXECUTE.bits,
1817 const GROUP_RWX = GROUP_READ.bits | GROUP_WRITE.bits | GROUP_EXECUTE.bits,
1818 const OTHER_RWX = OTHER_READ.bits | OTHER_WRITE.bits | OTHER_EXECUTE.bits,
1820 #[doc = "Permissions for user owned files, equivalent to 0644 on"]
1821 #[doc = "unix-like systems."]
1822 const USER_FILE = USER_READ.bits | USER_WRITE.bits | GROUP_READ.bits | OTHER_READ.bits,
1824 #[doc = "Permissions for user owned directories, equivalent to 0755 on"]
1825 #[doc = "unix-like systems."]
1826 const USER_DIR = USER_RWX.bits | GROUP_READ.bits | GROUP_EXECUTE.bits |
1827 OTHER_READ.bits | OTHER_EXECUTE.bits,
1829 #[doc = "Permissions for user owned executables, equivalent to 0755"]
1830 #[doc = "on unix-like systems."]
1831 const USER_EXEC = USER_DIR.bits,
1833 #[doc = "All possible permissions enabled."]
1834 const ALL_PERMISSIONS = USER_RWX.bits | GROUP_RWX.bits | OTHER_RWX.bits,
1837 #[allow(non_uppercase_statics)]
1838 #[deprecated = "use USER_READ instead"]
1839 const UserRead = USER_READ.bits,
1840 #[allow(non_uppercase_statics)]
1841 #[deprecated = "use USER_WRITE instead"]
1842 const UserWrite = USER_WRITE.bits,
1843 #[allow(non_uppercase_statics)]
1844 #[deprecated = "use USER_EXECUTE instead"]
1845 const UserExecute = USER_EXECUTE.bits,
1846 #[allow(non_uppercase_statics)]
1847 #[deprecated = "use GROUP_READ instead"]
1848 const GroupRead = GROUP_READ.bits,
1849 #[allow(non_uppercase_statics)]
1850 #[deprecated = "use GROUP_WRITE instead"]
1851 const GroupWrite = GROUP_WRITE.bits,
1852 #[allow(non_uppercase_statics)]
1853 #[deprecated = "use GROUP_EXECUTE instead"]
1854 const GroupExecute = GROUP_EXECUTE.bits,
1855 #[allow(non_uppercase_statics)]
1856 #[deprecated = "use OTHER_READ instead"]
1857 const OtherRead = OTHER_READ.bits,
1858 #[allow(non_uppercase_statics)]
1859 #[deprecated = "use OTHER_WRITE instead"]
1860 const OtherWrite = OTHER_WRITE.bits,
1861 #[allow(non_uppercase_statics)]
1862 #[deprecated = "use OTHER_EXECUTE instead"]
1863 const OtherExecute = OTHER_EXECUTE.bits,
1865 #[allow(non_uppercase_statics)]
1866 #[deprecated = "use USER_RWX instead"]
1867 const UserRWX = USER_RWX.bits,
1868 #[allow(non_uppercase_statics)]
1869 #[deprecated = "use GROUP_RWX instead"]
1870 const GroupRWX = GROUP_RWX.bits,
1871 #[allow(non_uppercase_statics)]
1872 #[deprecated = "use OTHER_RWX instead"]
1873 const OtherRWX = OTHER_RWX.bits,
1875 #[doc = "Deprecated: use `USER_FILE` instead."]
1876 #[allow(non_uppercase_statics)]
1877 #[deprecated = "use USER_FILE instead"]
1878 const UserFile = USER_FILE.bits,
1880 #[doc = "Deprecated: use `USER_DIR` instead."]
1881 #[allow(non_uppercase_statics)]
1882 #[deprecated = "use USER_DIR instead"]
1883 const UserDir = USER_DIR.bits,
1884 #[doc = "Deprecated: use `USER_EXEC` instead."]
1885 #[allow(non_uppercase_statics)]
1886 #[deprecated = "use USER_EXEC instead"]
1887 const UserExec = USER_EXEC.bits,
1889 #[doc = "Deprecated: use `ALL_PERMISSIONS` instead"]
1890 #[allow(non_uppercase_statics)]
1891 #[deprecated = "use ALL_PERMISSIONS instead"]
1892 const AllPermissions = ALL_PERMISSIONS.bits,
1896 impl Default for FilePermission {
1898 fn default() -> FilePermission { FilePermission::empty() }
1901 impl fmt::Show for FilePermission {
1902 fn fmt(&self, formatter: &mut fmt::Formatter) -> fmt::Result {
1903 formatter.fill = '0';
1904 formatter.width = Some(4);
1905 (&self.bits as &fmt::Octal).fmt(formatter)
1911 use super::{IoResult, Reader, MemReader, NoProgress, InvalidInput};
1915 #[deriving(Clone, PartialEq, Show)]
1916 enum BadReaderBehavior {
1921 struct BadReader<T> {
1923 behavior: Vec<BadReaderBehavior>,
1926 impl<T: Reader> BadReader<T> {
1927 fn new(r: T, behavior: Vec<BadReaderBehavior>) -> BadReader<T> {
1928 BadReader { behavior: behavior, r: r }
1932 impl<T: Reader> Reader for BadReader<T> {
1933 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> {
1934 let BadReader { ref mut behavior, ref mut r } = *self;
1936 if behavior.is_empty() {
1937 // fall back on good
1940 match behavior.as_mut_slice()[0] {
1941 GoodBehavior(0) => (),
1942 GoodBehavior(ref mut x) => {
1946 BadBehavior(0) => (),
1947 BadBehavior(ref mut x) => {
1958 fn test_read_at_least() {
1959 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1960 vec![GoodBehavior(uint::MAX)]);
1961 let mut buf = [0u8, ..5];
1962 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1963 assert!(r.read_exact(5).unwrap().len() == 5); // read_exact uses read_at_least
1964 assert!(r.read_at_least(0, buf).is_ok());
1966 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1967 vec![BadBehavior(50), GoodBehavior(uint::MAX)]);
1968 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1970 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1971 vec![BadBehavior(1), GoodBehavior(1),
1972 BadBehavior(50), GoodBehavior(uint::MAX)]);
1973 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1974 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1976 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1977 vec![BadBehavior(uint::MAX)]);
1978 assert_eq!(r.read_at_least(1, buf).unwrap_err().kind, NoProgress);
1980 let mut r = MemReader::new(b"hello, world!".to_vec());
1981 assert_eq!(r.read_at_least(5, buf).unwrap(), 5);
1982 assert_eq!(r.read_at_least(6, buf).unwrap_err().kind, InvalidInput);
1986 fn test_push_at_least() {
1987 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1988 vec![GoodBehavior(uint::MAX)]);
1989 let mut buf = Vec::new();
1990 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1991 assert!(r.push_at_least(0, 5, &mut buf).is_ok());
1993 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1994 vec![BadBehavior(50), GoodBehavior(uint::MAX)]);
1995 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1997 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
1998 vec![BadBehavior(1), GoodBehavior(1),
1999 BadBehavior(50), GoodBehavior(uint::MAX)]);
2000 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
2001 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
2003 let mut r = BadReader::new(MemReader::new(b"hello, world!".to_vec()),
2004 vec![BadBehavior(uint::MAX)]);
2005 assert_eq!(r.push_at_least(1, 5, &mut buf).unwrap_err().kind, NoProgress);
2007 let mut r = MemReader::new(b"hello, world!".to_vec());
2008 assert_eq!(r.push_at_least(5, 1, &mut buf).unwrap_err().kind, InvalidInput);
2015 assert_eq!(format!("{}", USER_READ), "0400".to_string());
2016 assert_eq!(format!("{}", USER_FILE), "0644".to_string());
2017 assert_eq!(format!("{}", USER_EXEC), "0755".to_string());
2018 assert_eq!(format!("{}", USER_RWX), "0700".to_string());
2019 assert_eq!(format!("{}", GROUP_RWX), "0070".to_string());
2020 assert_eq!(format!("{}", OTHER_RWX), "0007".to_string());
2021 assert_eq!(format!("{}", ALL_PERMISSIONS), "0777".to_string());
2022 assert_eq!(format!("{}", USER_READ | USER_WRITE | OTHER_WRITE), "0602".to_string());