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.
219 #![deny(unused_must_use)]
222 use collections::Collection;
228 use ops::{BitOr, BitAnd, Sub, Not};
229 use option::{Option, Some, None};
232 use result::{Ok, Err, Result};
234 use slice::{Vector, MutableVector, ImmutableVector};
235 use str::{Str, StrSlice, StrAllocating};
242 pub use self::stdio::stdin;
243 pub use self::stdio::stdout;
244 pub use self::stdio::stderr;
245 pub use self::stdio::print;
246 pub use self::stdio::println;
248 pub use self::fs::File;
249 pub use self::timer::Timer;
250 pub use self::net::ip::IpAddr;
251 pub use self::net::tcp::TcpListener;
252 pub use self::net::tcp::TcpStream;
253 pub use self::net::udp::UdpStream;
254 pub use self::pipe::PipeStream;
255 pub use self::process::{Process, Command};
256 pub use self::tempfile::TempDir;
258 pub use self::mem::{MemReader, BufReader, MemWriter, BufWriter};
259 pub use self::buffered::{BufferedReader, BufferedWriter, BufferedStream,
261 pub use self::comm_adapters::{ChanReader, ChanWriter};
263 // this comes first to get the iotest! macro
281 /// The default buffer size for various I/O operations
282 // libuv recommends 64k buffers to maximize throughput
283 // https://groups.google.com/forum/#!topic/libuv/oQO1HJAIDdA
284 static DEFAULT_BUF_SIZE: uint = 1024 * 64;
286 /// A convenient typedef of the return value of any I/O action.
287 pub type IoResult<T> = Result<T, IoError>;
289 /// The type passed to I/O condition handlers to indicate error
293 /// Is something like this sufficient? It's kind of archaic
294 #[deriving(PartialEq, Clone)]
296 /// An enumeration which can be matched against for determining the flavor
298 pub kind: IoErrorKind,
299 /// A human-readable description about the error
300 pub desc: &'static str,
301 /// Detailed information about this error, not always available
302 pub detail: Option<String>
306 /// Convert an `errno` value into an `IoError`.
308 /// If `detail` is `true`, the `detail` field of the `IoError`
309 /// struct is filled with an allocated string describing the error
310 /// in more detail, retrieved from the operating system.
311 pub fn from_errno(errno: uint, detail: bool) -> IoError {
314 fn get_err(errno: i32) -> (IoErrorKind, &'static str) {
316 libc::EOF => (EndOfFile, "end of file"),
317 libc::ERROR_NO_DATA => (BrokenPipe, "the pipe is being closed"),
318 libc::ERROR_FILE_NOT_FOUND => (FileNotFound, "file not found"),
319 libc::ERROR_INVALID_NAME => (InvalidInput, "invalid file name"),
320 libc::WSAECONNREFUSED => (ConnectionRefused, "connection refused"),
321 libc::WSAECONNRESET => (ConnectionReset, "connection reset"),
322 libc::ERROR_ACCESS_DENIED | libc::WSAEACCES =>
323 (PermissionDenied, "permission denied"),
324 libc::WSAEWOULDBLOCK => {
325 (ResourceUnavailable, "resource temporarily unavailable")
327 libc::WSAENOTCONN => (NotConnected, "not connected"),
328 libc::WSAECONNABORTED => (ConnectionAborted, "connection aborted"),
329 libc::WSAEADDRNOTAVAIL => (ConnectionRefused, "address not available"),
330 libc::WSAEADDRINUSE => (ConnectionRefused, "address in use"),
331 libc::ERROR_BROKEN_PIPE => (EndOfFile, "the pipe has ended"),
332 libc::ERROR_OPERATION_ABORTED =>
333 (TimedOut, "operation timed out"),
334 libc::WSAEINVAL => (InvalidInput, "invalid argument"),
335 libc::ERROR_CALL_NOT_IMPLEMENTED =>
336 (IoUnavailable, "function not implemented"),
337 libc::ERROR_INVALID_HANDLE =>
338 (MismatchedFileTypeForOperation,
339 "invalid handle provided to function"),
340 libc::ERROR_NOTHING_TO_TERMINATE =>
341 (InvalidInput, "no process to kill"),
343 // libuv maps this error code to EISDIR. we do too. if it is found
344 // to be incorrect, we can add in some more machinery to only
345 // return this message when ERROR_INVALID_FUNCTION after certain
347 libc::ERROR_INVALID_FUNCTION => (InvalidInput,
348 "illegal operation on a directory"),
350 _ => (OtherIoError, "unknown error")
355 fn get_err(errno: i32) -> (IoErrorKind, &'static str) {
356 // FIXME: this should probably be a bit more descriptive...
358 libc::EOF => (EndOfFile, "end of file"),
359 libc::ECONNREFUSED => (ConnectionRefused, "connection refused"),
360 libc::ECONNRESET => (ConnectionReset, "connection reset"),
361 libc::EPERM | libc::EACCES =>
362 (PermissionDenied, "permission denied"),
363 libc::EPIPE => (BrokenPipe, "broken pipe"),
364 libc::ENOTCONN => (NotConnected, "not connected"),
365 libc::ECONNABORTED => (ConnectionAborted, "connection aborted"),
366 libc::EADDRNOTAVAIL => (ConnectionRefused, "address not available"),
367 libc::EADDRINUSE => (ConnectionRefused, "address in use"),
368 libc::ENOENT => (FileNotFound, "no such file or directory"),
369 libc::EISDIR => (InvalidInput, "illegal operation on a directory"),
370 libc::ENOSYS => (IoUnavailable, "function not implemented"),
371 libc::EINVAL => (InvalidInput, "invalid argument"),
373 (MismatchedFileTypeForOperation,
374 "file descriptor is not a TTY"),
375 libc::ETIMEDOUT => (TimedOut, "operation timed out"),
376 libc::ECANCELED => (TimedOut, "operation aborted"),
378 // These two constants can have the same value on some systems,
379 // but different values on others, so we can't use a match
381 x if x == libc::EAGAIN || x == libc::EWOULDBLOCK =>
382 (ResourceUnavailable, "resource temporarily unavailable"),
384 _ => (OtherIoError, "unknown error")
388 let (kind, desc) = get_err(errno as i32);
392 detail: if detail && kind == OtherIoError {
393 Some(os::error_string(errno).as_slice().chars().map(|c| c.to_lowercase()).collect())
400 /// Retrieve the last error to occur as a (detailed) IoError.
402 /// This uses the OS `errno`, and so there should not be any task
403 /// descheduling or migration (other than that performed by the
404 /// operating system) between the call(s) for which errors are
405 /// being checked and the call of this function.
406 pub fn last_error() -> IoError {
407 IoError::from_errno(os::errno() as uint, true)
410 fn from_rtio_error(err: rtio::IoError) -> IoError {
411 let rtio::IoError { code, extra, detail } = err;
412 let mut ioerr = IoError::from_errno(code, false);
413 ioerr.detail = detail;
414 ioerr.kind = match ioerr.kind {
415 TimedOut if extra > 0 => ShortWrite(extra),
422 impl fmt::Show for IoError {
423 fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
425 IoError { kind: OtherIoError, desc: "unknown error", detail: Some(ref detail) } =>
426 write!(fmt, "{}", detail),
427 IoError { detail: None, desc, .. } =>
428 write!(fmt, "{}", desc),
429 IoError { detail: Some(ref detail), desc, .. } =>
430 write!(fmt, "{} ({})", desc, detail)
435 /// A list specifying general categories of I/O error.
436 #[deriving(PartialEq, Clone, Show)]
437 pub enum IoErrorKind {
438 /// Any I/O error not part of this list.
440 /// The operation could not complete because end of file was reached.
442 /// The file was not found.
444 /// The file permissions disallowed access to this file.
446 /// A network connection failed for some reason not specified in this list.
448 /// The network operation failed because the network connection was closed.
450 /// The connection was refused by the remote server.
452 /// The connection was reset by the remote server.
454 /// The connection was aborted (terminated) by the remote server.
456 /// The network operation failed because it was not connected yet.
458 /// The operation failed because a pipe was closed.
460 /// A file already existed with that name.
462 /// No file exists at that location.
464 /// The path did not specify the type of file that this operation required. For example,
465 /// attempting to copy a directory with the `fs::copy()` operation will fail with this error.
466 MismatchedFileTypeForOperation,
467 /// The operation temporarily failed (for example, because a signal was received), and retrying
470 /// No I/O functionality is available for this task.
472 /// A parameter was incorrect in a way that caused an I/O error not part of this list.
474 /// The I/O operation's timeout expired, causing it to be canceled.
476 /// This write operation failed to write all of its data.
478 /// Normally the write() method on a Writer guarantees that all of its data
479 /// has been written, but some operations may be terminated after only
480 /// partially writing some data. An example of this is a timed out write
481 /// which successfully wrote a known number of bytes, but bailed out after
484 /// The payload contained as part of this variant is the number of bytes
485 /// which are known to have been successfully written.
487 /// The Reader returned 0 bytes from `read()` too many times.
491 /// A trait that lets you add a `detail` to an IoError easily
492 trait UpdateIoError<T> {
493 /// Returns an IoError with updated description and detail
494 fn update_err(self, desc: &'static str, detail: |&IoError| -> String) -> Self;
496 /// Returns an IoError with updated detail
497 fn update_detail(self, detail: |&IoError| -> String) -> Self;
499 /// Returns an IoError with update description
500 fn update_desc(self, desc: &'static str) -> Self;
503 impl<T> UpdateIoError<T> for IoResult<T> {
504 fn update_err(self, desc: &'static str, detail: |&IoError| -> String) -> IoResult<T> {
505 self.map_err(|mut e| {
506 let detail = detail(&e);
508 e.detail = Some(detail);
513 fn update_detail(self, detail: |&IoError| -> String) -> IoResult<T> {
514 self.map_err(|mut e| { e.detail = Some(detail(&e)); e })
517 fn update_desc(self, desc: &'static str) -> IoResult<T> {
518 self.map_err(|mut e| { e.desc = desc; e })
522 static NO_PROGRESS_LIMIT: uint = 1000;
524 /// A trait for objects which are byte-oriented streams. Readers are defined by
525 /// one method, `read`. This function will block until data is available,
526 /// filling in the provided buffer with any data read.
528 /// Readers are intended to be composable with one another. Many objects
529 /// throughout the I/O and related libraries take and provide types which
530 /// implement the `Reader` trait.
533 // Only method which need to get implemented for this trait
535 /// Read bytes, up to the length of `buf` and place them in `buf`.
536 /// Returns the number of bytes read. The number of bytes read may
537 /// be less than the number requested, even 0. Returns `Err` on EOF.
541 /// If an error occurs during this I/O operation, then it is returned as
542 /// `Err(IoError)`. Note that end-of-file is considered an error, and can be
543 /// inspected for in the error's `kind` field. Also note that reading 0
544 /// bytes is not considered an error in all circumstances
546 /// # Implementation Note
548 /// When implementing this method on a new Reader, you are strongly encouraged
549 /// not to return 0 if you can avoid it.
550 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint>;
552 // Convenient helper methods based on the above methods
554 /// Reads at least `min` bytes and places them in `buf`.
555 /// Returns the number of bytes read.
557 /// This will continue to call `read` until at least `min` bytes have been
558 /// read. If `read` returns 0 too many times, `NoProgress` will be
563 /// If an error occurs at any point, that error is returned, and no further
565 fn read_at_least(&mut self, min: uint, buf: &mut [u8]) -> IoResult<uint> {
568 detail: Some("the buffer is too short".to_string()),
569 ..standard_error(InvalidInput)
576 match self.read(buf.mut_slice_from(read)) {
579 if zeroes >= NO_PROGRESS_LIMIT {
580 return Err(standard_error(NoProgress));
587 err@Err(_) => return err
594 /// Reads a single byte. Returns `Err` on EOF.
595 fn read_byte(&mut self) -> IoResult<u8> {
597 try!(self.read_at_least(1, buf));
601 /// Reads up to `len` bytes and appends them to a vector.
602 /// Returns the number of bytes read. The number of bytes read may be
603 /// less than the number requested, even 0. Returns Err on EOF.
607 /// If an error occurs during this I/O operation, then it is returned
608 /// as `Err(IoError)`. See `read()` for more details.
609 fn push(&mut self, len: uint, buf: &mut Vec<u8>) -> IoResult<uint> {
610 let start_len = buf.len();
611 buf.reserve_additional(len);
614 let s = unsafe { slice_vec_capacity(buf, start_len, start_len + len) };
617 unsafe { buf.set_len(start_len + n) };
621 /// Reads at least `min` bytes, but no more than `len`, and appends them to
623 /// Returns the number of bytes read.
625 /// This will continue to call `read` until at least `min` bytes have been
626 /// read. If `read` returns 0 too many times, `NoProgress` will be
631 /// If an error occurs at any point, that error is returned, and no further
633 fn push_at_least(&mut self, min: uint, len: uint, buf: &mut Vec<u8>) -> IoResult<uint> {
636 detail: Some("the buffer is too short".to_string()),
637 ..standard_error(InvalidInput)
641 let start_len = buf.len();
642 buf.reserve_additional(len);
644 // we can't just use self.read_at_least(min, slice) because we need to push
645 // successful reads onto the vector before any returned errors.
650 let s = unsafe { slice_vec_capacity(buf, start_len + read, start_len + len) };
651 try!(self.read_at_least(1, s))
653 unsafe { buf.set_len(start_len + read) };
658 /// Reads exactly `len` bytes and gives you back a new vector of length
663 /// Fails with the same conditions as `read`. Additionally returns error
664 /// on EOF. Note that if an error is returned, then some number of bytes may
665 /// have already been consumed from the underlying reader, and they are lost
666 /// (not returned as part of the error). If this is unacceptable, then it is
667 /// recommended to use the `push_at_least` or `read` methods.
668 fn read_exact(&mut self, len: uint) -> IoResult<Vec<u8>> {
669 let mut buf = Vec::with_capacity(len);
670 match self.push_at_least(len, len, &mut buf) {
676 /// Reads all remaining bytes from the stream.
680 /// Returns any non-EOF error immediately. Previously read bytes are
681 /// discarded when an error is returned.
683 /// When EOF is encountered, all bytes read up to that point are returned.
684 fn read_to_end(&mut self) -> IoResult<Vec<u8>> {
685 let mut buf = Vec::with_capacity(DEFAULT_BUF_SIZE);
687 match self.push_at_least(1, DEFAULT_BUF_SIZE, &mut buf) {
689 Err(ref e) if e.kind == EndOfFile => break,
690 Err(e) => return Err(e)
696 /// Reads all of the remaining bytes of this stream, interpreting them as a
697 /// UTF-8 encoded stream. The corresponding string is returned.
701 /// This function returns all of the same errors as `read_to_end` with an
702 /// additional error if the reader's contents are not a valid sequence of
704 fn read_to_str(&mut self) -> IoResult<String> {
705 self.read_to_end().and_then(|s| {
706 match str::from_utf8(s.as_slice()) {
707 Some(s) => Ok(s.to_string()),
708 None => Err(standard_error(InvalidInput)),
713 /// Create an iterator that reads a single byte on
714 /// each iteration, until EOF.
718 /// Any error other than `EndOfFile` that is produced by the underlying Reader
719 /// is returned by the iterator and should be handled by the caller.
720 fn bytes<'r>(&'r mut self) -> extensions::Bytes<'r, Self> {
721 extensions::Bytes::new(self)
724 // Byte conversion helpers
726 /// Reads `n` little-endian unsigned integer bytes.
728 /// `n` must be between 1 and 8, inclusive.
729 fn read_le_uint_n(&mut self, nbytes: uint) -> IoResult<u64> {
730 assert!(nbytes > 0 && nbytes <= 8);
736 val += (try!(self.read_u8()) as u64) << pos;
743 /// Reads `n` little-endian signed integer bytes.
745 /// `n` must be between 1 and 8, inclusive.
746 fn read_le_int_n(&mut self, nbytes: uint) -> IoResult<i64> {
747 self.read_le_uint_n(nbytes).map(|i| extend_sign(i, nbytes))
750 /// Reads `n` big-endian unsigned integer bytes.
752 /// `n` must be between 1 and 8, inclusive.
753 fn read_be_uint_n(&mut self, nbytes: uint) -> IoResult<u64> {
754 assert!(nbytes > 0 && nbytes <= 8);
760 val += (try!(self.read_u8()) as u64) << i * 8;
765 /// Reads `n` big-endian signed integer bytes.
767 /// `n` must be between 1 and 8, inclusive.
768 fn read_be_int_n(&mut self, nbytes: uint) -> IoResult<i64> {
769 self.read_be_uint_n(nbytes).map(|i| extend_sign(i, nbytes))
772 /// Reads a little-endian unsigned integer.
774 /// The number of bytes returned is system-dependent.
775 fn read_le_uint(&mut self) -> IoResult<uint> {
776 self.read_le_uint_n(uint::BYTES).map(|i| i as uint)
779 /// Reads a little-endian integer.
781 /// The number of bytes returned is system-dependent.
782 fn read_le_int(&mut self) -> IoResult<int> {
783 self.read_le_int_n(int::BYTES).map(|i| i as int)
786 /// Reads a big-endian unsigned integer.
788 /// The number of bytes returned is system-dependent.
789 fn read_be_uint(&mut self) -> IoResult<uint> {
790 self.read_be_uint_n(uint::BYTES).map(|i| i as uint)
793 /// Reads a big-endian integer.
795 /// The number of bytes returned is system-dependent.
796 fn read_be_int(&mut self) -> IoResult<int> {
797 self.read_be_int_n(int::BYTES).map(|i| i as int)
800 /// Reads a big-endian `u64`.
802 /// `u64`s are 8 bytes long.
803 fn read_be_u64(&mut self) -> IoResult<u64> {
804 self.read_be_uint_n(8)
807 /// Reads a big-endian `u32`.
809 /// `u32`s are 4 bytes long.
810 fn read_be_u32(&mut self) -> IoResult<u32> {
811 self.read_be_uint_n(4).map(|i| i as u32)
814 /// Reads a big-endian `u16`.
816 /// `u16`s are 2 bytes long.
817 fn read_be_u16(&mut self) -> IoResult<u16> {
818 self.read_be_uint_n(2).map(|i| i as u16)
821 /// Reads a big-endian `i64`.
823 /// `i64`s are 8 bytes long.
824 fn read_be_i64(&mut self) -> IoResult<i64> {
825 self.read_be_int_n(8)
828 /// Reads a big-endian `i32`.
830 /// `i32`s are 4 bytes long.
831 fn read_be_i32(&mut self) -> IoResult<i32> {
832 self.read_be_int_n(4).map(|i| i as i32)
835 /// Reads a big-endian `i16`.
837 /// `i16`s are 2 bytes long.
838 fn read_be_i16(&mut self) -> IoResult<i16> {
839 self.read_be_int_n(2).map(|i| i as i16)
842 /// Reads a big-endian `f64`.
844 /// `f64`s are 8 byte, IEEE754 double-precision floating point numbers.
845 fn read_be_f64(&mut self) -> IoResult<f64> {
846 self.read_be_u64().map(|i| unsafe {
847 transmute::<u64, f64>(i)
851 /// Reads a big-endian `f32`.
853 /// `f32`s are 4 byte, IEEE754 single-precision floating point numbers.
854 fn read_be_f32(&mut self) -> IoResult<f32> {
855 self.read_be_u32().map(|i| unsafe {
856 transmute::<u32, f32>(i)
860 /// Reads a little-endian `u64`.
862 /// `u64`s are 8 bytes long.
863 fn read_le_u64(&mut self) -> IoResult<u64> {
864 self.read_le_uint_n(8)
867 /// Reads a little-endian `u32`.
869 /// `u32`s are 4 bytes long.
870 fn read_le_u32(&mut self) -> IoResult<u32> {
871 self.read_le_uint_n(4).map(|i| i as u32)
874 /// Reads a little-endian `u16`.
876 /// `u16`s are 2 bytes long.
877 fn read_le_u16(&mut self) -> IoResult<u16> {
878 self.read_le_uint_n(2).map(|i| i as u16)
881 /// Reads a little-endian `i64`.
883 /// `i64`s are 8 bytes long.
884 fn read_le_i64(&mut self) -> IoResult<i64> {
885 self.read_le_int_n(8)
888 /// Reads a little-endian `i32`.
890 /// `i32`s are 4 bytes long.
891 fn read_le_i32(&mut self) -> IoResult<i32> {
892 self.read_le_int_n(4).map(|i| i as i32)
895 /// Reads a little-endian `i16`.
897 /// `i16`s are 2 bytes long.
898 fn read_le_i16(&mut self) -> IoResult<i16> {
899 self.read_le_int_n(2).map(|i| i as i16)
902 /// Reads a little-endian `f64`.
904 /// `f64`s are 8 byte, IEEE754 double-precision floating point numbers.
905 fn read_le_f64(&mut self) -> IoResult<f64> {
906 self.read_le_u64().map(|i| unsafe {
907 transmute::<u64, f64>(i)
911 /// Reads a little-endian `f32`.
913 /// `f32`s are 4 byte, IEEE754 single-precision floating point numbers.
914 fn read_le_f32(&mut self) -> IoResult<f32> {
915 self.read_le_u32().map(|i| unsafe {
916 transmute::<u32, f32>(i)
922 /// `u8`s are 1 byte.
923 fn read_u8(&mut self) -> IoResult<u8> {
929 /// `i8`s are 1 byte.
930 fn read_i8(&mut self) -> IoResult<i8> {
931 self.read_byte().map(|i| i as i8)
934 /// Creates a wrapper around a mutable reference to the reader.
936 /// This is useful to allow applying adaptors while still
937 /// retaining ownership of the original value.
938 fn by_ref<'a>(&'a mut self) -> RefReader<'a, Self> {
939 RefReader { inner: self }
943 impl Reader for Box<Reader> {
944 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> { self.read(buf) }
947 impl<'a> Reader for &'a mut Reader {
948 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> { self.read(buf) }
951 /// Returns a slice of `v` between `start` and `end`.
953 /// Similar to `slice()` except this function only bounds the slice on the
954 /// capacity of `v`, not the length.
958 /// Fails when `start` or `end` point outside the capacity of `v`, or when
960 // Private function here because we aren't sure if we want to expose this as
961 // API yet. If so, it should be a method on Vec.
962 unsafe fn slice_vec_capacity<'a, T>(v: &'a mut Vec<T>, start: uint, end: uint) -> &'a mut [T] {
966 assert!(start <= end);
967 assert!(end <= v.capacity());
969 data: v.as_ptr().offset(start as int),
974 /// A `RefReader` is a struct implementing `Reader` which contains a reference
975 /// to another reader. This is often useful when composing streams.
981 /// # fn process_input<R: Reader>(r: R) {}
984 /// use std::io::util::LimitReader;
986 /// let mut stream = io::stdin();
988 /// // Only allow the function to process at most one kilobyte of input
990 /// let stream = LimitReader::new(stream.by_ref(), 1024);
991 /// process_input(stream);
994 /// // 'stream' is still available for use here
998 pub struct RefReader<'a, R> {
999 /// The underlying reader which this is referencing
1003 impl<'a, R: Reader> Reader for RefReader<'a, R> {
1004 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> { self.inner.read(buf) }
1007 impl<'a, R: Buffer> Buffer for RefReader<'a, R> {
1008 fn fill_buf<'a>(&'a mut self) -> IoResult<&'a [u8]> { self.inner.fill_buf() }
1009 fn consume(&mut self, amt: uint) { self.inner.consume(amt) }
1012 fn extend_sign(val: u64, nbytes: uint) -> i64 {
1013 let shift = (8 - nbytes) * 8;
1014 (val << shift) as i64 >> shift
1017 /// A trait for objects which are byte-oriented streams. Writers are defined by
1018 /// one method, `write`. This function will block until the provided buffer of
1019 /// bytes has been entirely written, and it will return any failures which occur.
1021 /// Another commonly overridden method is the `flush` method for writers such as
1022 /// buffered writers.
1024 /// Writers are intended to be composable with one another. Many objects
1025 /// throughout the I/O and related libraries take and provide types which
1026 /// implement the `Writer` trait.
1028 /// Write the entirety of a given buffer
1032 /// If an error happens during the I/O operation, the error is returned as
1033 /// `Err`. Note that it is considered an error if the entire buffer could
1034 /// not be written, and if an error is returned then it is unknown how much
1035 /// data (if any) was actually written.
1036 fn write(&mut self, buf: &[u8]) -> IoResult<()>;
1038 /// Flush this output stream, ensuring that all intermediately buffered
1039 /// contents reach their destination.
1041 /// This is by default a no-op and implementers of the `Writer` trait should
1042 /// decide whether their stream needs to be buffered or not.
1043 fn flush(&mut self) -> IoResult<()> { Ok(()) }
1045 /// Writes a formatted string into this writer, returning any error
1048 /// This method is primarily used to interface with the `format_args!`
1049 /// macro, but it is rare that this should explicitly be called. The
1050 /// `write!` macro should be favored to invoke this method instead.
1054 /// This function will return any I/O error reported while formatting.
1055 fn write_fmt(&mut self, fmt: &fmt::Arguments) -> IoResult<()> {
1056 // Create a shim which translates a Writer to a FormatWriter and saves
1057 // off I/O errors. instead of discarding them
1058 struct Adaptor<'a, T> {
1060 error: IoResult<()>,
1062 impl<'a, T: Writer> fmt::FormatWriter for Adaptor<'a, T> {
1063 fn write(&mut self, bytes: &[u8]) -> fmt::Result {
1064 match self.inner.write(bytes) {
1067 self.error = Err(e);
1068 Err(fmt::WriteError)
1074 let mut output = Adaptor { inner: self, error: Ok(()) };
1075 match fmt::write(&mut output, fmt) {
1077 Err(..) => output.error
1081 /// Write a rust string into this sink.
1083 /// The bytes written will be the UTF-8 encoded version of the input string.
1084 /// If other encodings are desired, it is recommended to compose this stream
1085 /// with another performing the conversion, or to use `write` with a
1086 /// converted byte-array instead.
1088 fn write_str(&mut self, s: &str) -> IoResult<()> {
1089 self.write(s.as_bytes())
1092 /// Writes a string into this sink, and then writes a literal newline (`\n`)
1093 /// byte afterwards. Note that the writing of the newline is *not* atomic in
1094 /// the sense that the call to `write` is invoked twice (once with the
1095 /// string and once with a newline character).
1097 /// If other encodings or line ending flavors are desired, it is recommended
1098 /// that the `write` method is used specifically instead.
1100 fn write_line(&mut self, s: &str) -> IoResult<()> {
1101 self.write_str(s).and_then(|()| self.write(['\n' as u8]))
1104 /// Write a single char, encoded as UTF-8.
1106 fn write_char(&mut self, c: char) -> IoResult<()> {
1107 let mut buf = [0u8, ..4];
1108 let n = c.encode_utf8(buf.as_mut_slice());
1109 self.write(buf.slice_to(n))
1112 /// Write the result of passing n through `int::to_str_bytes`.
1114 fn write_int(&mut self, n: int) -> IoResult<()> {
1115 write!(self, "{:d}", n)
1118 /// Write the result of passing n through `uint::to_str_bytes`.
1120 fn write_uint(&mut self, n: uint) -> IoResult<()> {
1121 write!(self, "{:u}", n)
1124 /// Write a little-endian uint (number of bytes depends on system).
1126 fn write_le_uint(&mut self, n: uint) -> IoResult<()> {
1127 extensions::u64_to_le_bytes(n as u64, uint::BYTES, |v| self.write(v))
1130 /// Write a little-endian int (number of bytes depends on system).
1132 fn write_le_int(&mut self, n: int) -> IoResult<()> {
1133 extensions::u64_to_le_bytes(n as u64, int::BYTES, |v| self.write(v))
1136 /// Write a big-endian uint (number of bytes depends on system).
1138 fn write_be_uint(&mut self, n: uint) -> IoResult<()> {
1139 extensions::u64_to_be_bytes(n as u64, uint::BYTES, |v| self.write(v))
1142 /// Write a big-endian int (number of bytes depends on system).
1144 fn write_be_int(&mut self, n: int) -> IoResult<()> {
1145 extensions::u64_to_be_bytes(n as u64, int::BYTES, |v| self.write(v))
1148 /// Write a big-endian u64 (8 bytes).
1150 fn write_be_u64(&mut self, n: u64) -> IoResult<()> {
1151 extensions::u64_to_be_bytes(n, 8u, |v| self.write(v))
1154 /// Write a big-endian u32 (4 bytes).
1156 fn write_be_u32(&mut self, n: u32) -> IoResult<()> {
1157 extensions::u64_to_be_bytes(n as u64, 4u, |v| self.write(v))
1160 /// Write a big-endian u16 (2 bytes).
1162 fn write_be_u16(&mut self, n: u16) -> IoResult<()> {
1163 extensions::u64_to_be_bytes(n as u64, 2u, |v| self.write(v))
1166 /// Write a big-endian i64 (8 bytes).
1168 fn write_be_i64(&mut self, n: i64) -> IoResult<()> {
1169 extensions::u64_to_be_bytes(n as u64, 8u, |v| self.write(v))
1172 /// Write a big-endian i32 (4 bytes).
1174 fn write_be_i32(&mut self, n: i32) -> IoResult<()> {
1175 extensions::u64_to_be_bytes(n as u64, 4u, |v| self.write(v))
1178 /// Write a big-endian i16 (2 bytes).
1180 fn write_be_i16(&mut self, n: i16) -> IoResult<()> {
1181 extensions::u64_to_be_bytes(n as u64, 2u, |v| self.write(v))
1184 /// Write a big-endian IEEE754 double-precision floating-point (8 bytes).
1186 fn write_be_f64(&mut self, f: f64) -> IoResult<()> {
1188 self.write_be_u64(transmute(f))
1192 /// Write a big-endian IEEE754 single-precision floating-point (4 bytes).
1194 fn write_be_f32(&mut self, f: f32) -> IoResult<()> {
1196 self.write_be_u32(transmute(f))
1200 /// Write a little-endian u64 (8 bytes).
1202 fn write_le_u64(&mut self, n: u64) -> IoResult<()> {
1203 extensions::u64_to_le_bytes(n, 8u, |v| self.write(v))
1206 /// Write a little-endian u32 (4 bytes).
1208 fn write_le_u32(&mut self, n: u32) -> IoResult<()> {
1209 extensions::u64_to_le_bytes(n as u64, 4u, |v| self.write(v))
1212 /// Write a little-endian u16 (2 bytes).
1214 fn write_le_u16(&mut self, n: u16) -> IoResult<()> {
1215 extensions::u64_to_le_bytes(n as u64, 2u, |v| self.write(v))
1218 /// Write a little-endian i64 (8 bytes).
1220 fn write_le_i64(&mut self, n: i64) -> IoResult<()> {
1221 extensions::u64_to_le_bytes(n as u64, 8u, |v| self.write(v))
1224 /// Write a little-endian i32 (4 bytes).
1226 fn write_le_i32(&mut self, n: i32) -> IoResult<()> {
1227 extensions::u64_to_le_bytes(n as u64, 4u, |v| self.write(v))
1230 /// Write a little-endian i16 (2 bytes).
1232 fn write_le_i16(&mut self, n: i16) -> IoResult<()> {
1233 extensions::u64_to_le_bytes(n as u64, 2u, |v| self.write(v))
1236 /// Write a little-endian IEEE754 double-precision floating-point
1239 fn write_le_f64(&mut self, f: f64) -> IoResult<()> {
1241 self.write_le_u64(transmute(f))
1245 /// Write a little-endian IEEE754 single-precision floating-point
1248 fn write_le_f32(&mut self, f: f32) -> IoResult<()> {
1250 self.write_le_u32(transmute(f))
1254 /// Write a u8 (1 byte).
1256 fn write_u8(&mut self, n: u8) -> IoResult<()> {
1260 /// Write an i8 (1 byte).
1262 fn write_i8(&mut self, n: i8) -> IoResult<()> {
1263 self.write([n as u8])
1266 /// Creates a wrapper around a mutable reference to the writer.
1268 /// This is useful to allow applying wrappers while still
1269 /// retaining ownership of the original value.
1271 fn by_ref<'a>(&'a mut self) -> RefWriter<'a, Self> {
1272 RefWriter { inner: self }
1276 impl Writer for Box<Writer> {
1278 fn write(&mut self, buf: &[u8]) -> IoResult<()> { self.write(buf) }
1281 fn flush(&mut self) -> IoResult<()> { self.flush() }
1284 impl<'a> Writer for &'a mut Writer {
1286 fn write(&mut self, buf: &[u8]) -> IoResult<()> { self.write(buf) }
1289 fn flush(&mut self) -> IoResult<()> { self.flush() }
1292 /// A `RefWriter` is a struct implementing `Writer` which contains a reference
1293 /// to another writer. This is often useful when composing streams.
1299 /// # fn process_input<R: Reader>(r: R) {}
1301 /// use std::io::util::TeeReader;
1302 /// use std::io::{stdin, MemWriter};
1304 /// let mut output = MemWriter::new();
1307 /// // Don't give ownership of 'output' to the 'tee'. Instead we keep a
1308 /// // handle to it in the outer scope
1309 /// let mut tee = TeeReader::new(stdin(), output.by_ref());
1310 /// process_input(tee);
1313 /// println!("input processed: {}", output.unwrap());
1316 pub struct RefWriter<'a, W> {
1317 /// The underlying writer which this is referencing
1321 impl<'a, W: Writer> Writer for RefWriter<'a, W> {
1323 fn write(&mut self, buf: &[u8]) -> IoResult<()> { self.inner.write(buf) }
1326 fn flush(&mut self) -> IoResult<()> { self.inner.flush() }
1330 /// A Stream is a readable and a writable object. Data written is typically
1331 /// received by the object which reads receive data from.
1332 pub trait Stream: Reader + Writer { }
1334 impl<T: Reader + Writer> Stream for T {}
1336 /// An iterator that reads a line on each iteration,
1337 /// until `.read_line()` encounters `EndOfFile`.
1339 /// # Notes about the Iteration Protocol
1341 /// The `Lines` may yield `None` and thus terminate
1342 /// an iteration, but continue to yield elements if iteration
1343 /// is attempted again.
1347 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1348 /// is returned by the iterator and should be handled by the caller.
1349 pub struct Lines<'r, T> {
1353 impl<'r, T: Buffer> Iterator<IoResult<String>> for Lines<'r, T> {
1354 fn next(&mut self) -> Option<IoResult<String>> {
1355 match self.buffer.read_line() {
1356 Ok(x) => Some(Ok(x)),
1357 Err(IoError { kind: EndOfFile, ..}) => None,
1358 Err(y) => Some(Err(y))
1363 /// An iterator that reads a utf8-encoded character on each iteration,
1364 /// until `.read_char()` encounters `EndOfFile`.
1366 /// # Notes about the Iteration Protocol
1368 /// The `Chars` may yield `None` and thus terminate
1369 /// an iteration, but continue to yield elements if iteration
1370 /// is attempted again.
1374 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1375 /// is returned by the iterator and should be handled by the caller.
1376 pub struct Chars<'r, T> {
1380 impl<'r, T: Buffer> Iterator<IoResult<char>> for Chars<'r, T> {
1381 fn next(&mut self) -> Option<IoResult<char>> {
1382 match self.buffer.read_char() {
1383 Ok(x) => Some(Ok(x)),
1384 Err(IoError { kind: EndOfFile, ..}) => None,
1385 Err(y) => Some(Err(y))
1390 /// A Buffer is a type of reader which has some form of internal buffering to
1391 /// allow certain kinds of reading operations to be more optimized than others.
1392 /// This type extends the `Reader` trait with a few methods that are not
1393 /// possible to reasonably implement with purely a read interface.
1394 pub trait Buffer: Reader {
1395 /// Fills the internal buffer of this object, returning the buffer contents.
1396 /// Note that none of the contents will be "read" in the sense that later
1397 /// calling `read` may return the same contents.
1399 /// The `consume` function must be called with the number of bytes that are
1400 /// consumed from this buffer returned to ensure that the bytes are never
1405 /// This function will return an I/O error if the underlying reader was
1406 /// read, but returned an error. Note that it is not an error to return a
1407 /// 0-length buffer.
1408 fn fill_buf<'a>(&'a mut self) -> IoResult<&'a [u8]>;
1410 /// Tells this buffer that `amt` bytes have been consumed from the buffer,
1411 /// so they should no longer be returned in calls to `read`.
1412 fn consume(&mut self, amt: uint);
1414 /// Reads the next line of input, interpreted as a sequence of UTF-8
1415 /// encoded unicode codepoints. If a newline is encountered, then the
1416 /// newline is contained in the returned string.
1423 /// let mut reader = io::stdin();
1424 /// let input = reader.read_line().ok().unwrap_or("nothing".to_string());
1429 /// This function has the same error semantics as `read_until`:
1431 /// * All non-EOF errors will be returned immediately
1432 /// * If an error is returned previously consumed bytes are lost
1433 /// * EOF is only returned if no bytes have been read
1434 /// * Reach EOF may mean that the delimiter is not present in the return
1437 /// Additionally, this function can fail if the line of input read is not a
1438 /// valid UTF-8 sequence of bytes.
1439 fn read_line(&mut self) -> IoResult<String> {
1440 self.read_until('\n' as u8).and_then(|line|
1441 match str::from_utf8(line.as_slice()) {
1442 Some(s) => Ok(s.to_string()),
1443 None => Err(standard_error(InvalidInput)),
1448 /// Create an iterator that reads a line on each iteration until EOF.
1452 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1453 /// is returned by the iterator and should be handled by the caller.
1454 fn lines<'r>(&'r mut self) -> Lines<'r, Self> {
1455 Lines { buffer: self }
1458 /// Reads a sequence of bytes leading up to a specified delimiter. Once the
1459 /// specified byte is encountered, reading ceases and the bytes up to and
1460 /// including the delimiter are returned.
1464 /// If any I/O error is encountered other than EOF, the error is immediately
1465 /// returned. Note that this may discard bytes which have already been read,
1466 /// and those bytes will *not* be returned. It is recommended to use other
1467 /// methods if this case is worrying.
1469 /// If EOF is encountered, then this function will return EOF if 0 bytes
1470 /// have been read, otherwise the pending byte buffer is returned. This
1471 /// is the reason that the byte buffer returned may not always contain the
1473 fn read_until(&mut self, byte: u8) -> IoResult<Vec<u8>> {
1474 let mut res = Vec::new();
1479 let available = match self.fill_buf() {
1481 Err(ref e) if res.len() > 0 && e.kind == EndOfFile => {
1485 Err(e) => return Err(e)
1487 match available.iter().position(|&b| b == byte) {
1489 res.push_all(available.slice_to(i + 1));
1494 res.push_all(available);
1495 used = available.len();
1505 /// Reads the next utf8-encoded character from the underlying stream.
1509 /// If an I/O error occurs, or EOF, then this function will return `Err`.
1510 /// This function will also return error if the stream does not contain a
1511 /// valid utf-8 encoded codepoint as the next few bytes in the stream.
1512 fn read_char(&mut self) -> IoResult<char> {
1513 let first_byte = try!(self.read_byte());
1514 let width = str::utf8_char_width(first_byte);
1515 if width == 1 { return Ok(first_byte as char) }
1516 if width == 0 { return Err(standard_error(InvalidInput)) } // not utf8
1517 let mut buf = [first_byte, 0, 0, 0];
1520 while start < width {
1521 match try!(self.read(buf.mut_slice(start, width))) {
1522 n if n == width - start => break,
1523 n if n < width - start => { start += n; }
1524 _ => return Err(standard_error(InvalidInput)),
1528 match str::from_utf8(buf.slice_to(width)) {
1529 Some(s) => Ok(s.char_at(0)),
1530 None => Err(standard_error(InvalidInput))
1534 /// Create an iterator that reads a utf8-encoded character on each iteration
1539 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1540 /// is returned by the iterator and should be handled by the caller.
1541 fn chars<'r>(&'r mut self) -> Chars<'r, Self> {
1542 Chars { buffer: self }
1546 /// When seeking, the resulting cursor is offset from a base by the offset given
1547 /// to the `seek` function. The base used is specified by this enumeration.
1548 pub enum SeekStyle {
1549 /// Seek from the beginning of the stream
1551 /// Seek from the end of the stream
1553 /// Seek from the current position
1557 /// An object implementing `Seek` internally has some form of cursor which can
1558 /// be moved within a stream of bytes. The stream typically has a fixed size,
1559 /// allowing seeking relative to either end.
1561 /// Return position of file cursor in the stream
1562 fn tell(&self) -> IoResult<u64>;
1564 /// Seek to an offset in a stream
1566 /// A successful seek clears the EOF indicator. Seeking beyond EOF is
1567 /// allowed, but seeking before position 0 is not allowed.
1571 /// * Seeking to a negative offset is considered an error
1572 /// * Seeking past the end of the stream does not modify the underlying
1573 /// stream, but the next write may cause the previous data to be filled in
1574 /// with a bit pattern.
1575 fn seek(&mut self, pos: i64, style: SeekStyle) -> IoResult<()>;
1578 /// A listener is a value that can consume itself to start listening for
1581 /// Doing so produces some sort of Acceptor.
1582 pub trait Listener<T, A: Acceptor<T>> {
1583 /// Spin up the listener and start queuing incoming connections
1587 /// Returns `Err` if this listener could not be bound to listen for
1588 /// connections. In all cases, this listener is consumed.
1589 fn listen(self) -> IoResult<A>;
1592 /// An acceptor is a value that presents incoming connections
1593 pub trait Acceptor<T> {
1594 /// Wait for and accept an incoming connection
1598 /// Returns `Err` if an I/O error is encountered.
1599 fn accept(&mut self) -> IoResult<T>;
1601 /// Create an iterator over incoming connection attempts.
1603 /// Note that I/O errors will be yielded by the iterator itself.
1604 fn incoming<'r>(&'r mut self) -> IncomingConnections<'r, Self> {
1605 IncomingConnections { inc: self }
1609 /// An infinite iterator over incoming connection attempts.
1610 /// Calling `next` will block the task until a connection is attempted.
1612 /// Since connection attempts can continue forever, this iterator always returns
1613 /// `Some`. The `Some` contains the `IoResult` representing whether the
1614 /// connection attempt was successful. A successful connection will be wrapped
1615 /// in `Ok`. A failed connection is represented as an `Err`.
1616 pub struct IncomingConnections<'a, A> {
1620 impl<'a, T, A: Acceptor<T>> Iterator<IoResult<T>> for IncomingConnections<'a, A> {
1621 fn next(&mut self) -> Option<IoResult<T>> {
1622 Some(self.inc.accept())
1626 /// Creates a standard error for a commonly used flavor of error. The `detail`
1627 /// field of the returned error will always be `None`.
1634 /// let eof = io::standard_error(io::EndOfFile);
1635 /// let einval = io::standard_error(io::InvalidInput);
1637 pub fn standard_error(kind: IoErrorKind) -> IoError {
1638 let desc = match kind {
1639 EndOfFile => "end of file",
1640 IoUnavailable => "I/O is unavailable",
1641 InvalidInput => "invalid input",
1642 OtherIoError => "unknown I/O error",
1643 FileNotFound => "file not found",
1644 PermissionDenied => "permission denied",
1645 ConnectionFailed => "connection failed",
1646 Closed => "stream is closed",
1647 ConnectionRefused => "connection refused",
1648 ConnectionReset => "connection reset",
1649 ConnectionAborted => "connection aborted",
1650 NotConnected => "not connected",
1651 BrokenPipe => "broken pipe",
1652 PathAlreadyExists => "file already exists",
1653 PathDoesntExist => "no such file",
1654 MismatchedFileTypeForOperation => "mismatched file type",
1655 ResourceUnavailable => "resource unavailable",
1656 TimedOut => "operation timed out",
1657 ShortWrite(..) => "short write",
1658 NoProgress => "no progress",
1667 /// A mode specifies how a file should be opened or created. These modes are
1668 /// passed to `File::open_mode` and are used to control where the file is
1669 /// positioned when it is initially opened.
1671 /// Opens a file positioned at the beginning.
1673 /// Opens a file positioned at EOF.
1675 /// Opens a file, truncating it if it already exists.
1679 /// Access permissions with which the file should be opened. `File`s
1680 /// opened with `Read` will return an error if written to.
1681 pub enum FileAccess {
1682 /// Read-only access, requests to write will result in an error
1684 /// Write-only access, requests to read will result in an error
1686 /// Read-write access, no requests are denied by default
1690 /// Different kinds of files which can be identified by a call to stat
1691 #[deriving(PartialEq, Show, Hash)]
1693 /// This is a normal file, corresponding to `S_IFREG`
1696 /// This file is a directory, corresponding to `S_IFDIR`
1699 /// This file is a named pipe, corresponding to `S_IFIFO`
1702 /// This file is a block device, corresponding to `S_IFBLK`
1705 /// This file is a symbolic link to another file, corresponding to `S_IFLNK`
1708 /// The type of this file is not recognized as one of the other categories
1712 /// A structure used to describe metadata information about a file. This
1713 /// structure is created through the `stat` method on a `Path`.
1720 /// let info = match Path::new("foo.txt").stat() {
1721 /// Ok(stat) => stat,
1722 /// Err(e) => fail!("couldn't read foo.txt: {}", e),
1725 /// println!("byte size: {}", info.size);
1729 pub struct FileStat {
1730 /// The size of the file, in bytes
1732 /// The kind of file this path points to (directory, file, pipe, etc.)
1734 /// The file permissions currently on the file
1735 pub perm: FilePermission,
1737 // FIXME(#10301): These time fields are pretty useless without an actual
1738 // time representation, what are the milliseconds relative
1741 /// The time that the file was created at, in platform-dependent
1744 /// The time that this file was last modified, in platform-dependent
1747 /// The time that this file was last accessed, in platform-dependent
1751 /// Information returned by stat() which is not guaranteed to be
1752 /// platform-independent. This information may be useful on some platforms,
1753 /// but it may have different meanings or no meaning at all on other
1756 /// Usage of this field is discouraged, but if access is desired then the
1757 /// fields are located here.
1759 pub unstable: UnstableFileStat,
1762 /// This structure represents all of the possible information which can be
1763 /// returned from a `stat` syscall which is not contained in the `FileStat`
1764 /// structure. This information is not necessarily platform independent, and may
1765 /// have different meanings or no meaning at all on some platforms.
1768 pub struct UnstableFileStat {
1769 /// The ID of the device containing the file.
1771 /// The file serial number.
1775 /// The number of hard links to this file.
1777 /// The user ID of the file.
1779 /// The group ID of the file.
1781 /// The optimal block size for I/O.
1783 /// The blocks allocated for this file.
1785 /// User-defined flags for the file.
1787 /// The file generation number.
1792 #[doc="A set of permissions for a file or directory is represented
1793 by a set of flags which are or'd together."]
1796 flags FilePermission: u32 {
1797 static UserRead = 0o400,
1798 static UserWrite = 0o200,
1799 static UserExecute = 0o100,
1800 static GroupRead = 0o040,
1801 static GroupWrite = 0o020,
1802 static GroupExecute = 0o010,
1803 static OtherRead = 0o004,
1804 static OtherWrite = 0o002,
1805 static OtherExecute = 0o001,
1807 static UserRWX = UserRead.bits | UserWrite.bits | UserExecute.bits,
1808 static GroupRWX = GroupRead.bits | GroupWrite.bits | GroupExecute.bits,
1809 static OtherRWX = OtherRead.bits | OtherWrite.bits | OtherExecute.bits,
1811 #[doc="Permissions for user owned files, equivalent to 0644 on
1812 unix-like systems."]
1813 static UserFile = UserRead.bits | UserWrite.bits | GroupRead.bits | OtherRead.bits,
1815 #[doc="Permissions for user owned directories, equivalent to 0755 on
1816 unix-like systems."]
1817 static UserDir = UserRWX.bits | GroupRead.bits | GroupExecute.bits |
1818 OtherRead.bits | OtherExecute.bits,
1820 #[doc="Permissions for user owned executables, equivalent to 0755
1821 on unix-like systems."]
1822 static UserExec = UserDir.bits,
1824 #[doc="All possible permissions enabled."]
1825 static AllPermissions = UserRWX.bits | GroupRWX.bits | OtherRWX.bits
1831 use super::{IoResult, Reader, MemReader, NoProgress, InvalidInput};
1835 #[deriving(Clone, PartialEq, Show)]
1836 enum BadReaderBehavior {
1841 struct BadReader<T> {
1843 behavior: Vec<BadReaderBehavior>,
1846 impl<T: Reader> BadReader<T> {
1847 fn new(r: T, behavior: Vec<BadReaderBehavior>) -> BadReader<T> {
1848 BadReader { behavior: behavior, r: r }
1852 impl<T: Reader> Reader for BadReader<T> {
1853 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> {
1854 let BadReader { ref mut behavior, ref mut r } = *self;
1856 if behavior.is_empty() {
1857 // fall back on good
1860 match behavior.as_mut_slice()[0] {
1861 GoodBehavior(0) => (),
1862 GoodBehavior(ref mut x) => {
1866 BadBehavior(0) => (),
1867 BadBehavior(ref mut x) => {
1878 fn test_read_at_least() {
1879 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1880 Vec::from_slice([GoodBehavior(uint::MAX)]));
1881 let mut buf = [0u8, ..5];
1882 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1883 assert!(r.read_exact(5).unwrap().len() == 5); // read_exact uses read_at_least
1884 assert!(r.read_at_least(0, buf).is_ok());
1886 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1887 Vec::from_slice([BadBehavior(50), GoodBehavior(uint::MAX)]));
1888 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1890 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1891 Vec::from_slice([BadBehavior(1), GoodBehavior(1),
1892 BadBehavior(50), GoodBehavior(uint::MAX)]));
1893 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1894 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1896 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1897 Vec::from_slice([BadBehavior(uint::MAX)]));
1898 assert_eq!(r.read_at_least(1, buf).unwrap_err().kind, NoProgress);
1900 let mut r = MemReader::new(Vec::from_slice(b"hello, world!"));
1901 assert_eq!(r.read_at_least(5, buf).unwrap(), 5);
1902 assert_eq!(r.read_at_least(6, buf).unwrap_err().kind, InvalidInput);
1906 fn test_push_at_least() {
1907 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1908 Vec::from_slice([GoodBehavior(uint::MAX)]));
1909 let mut buf = Vec::new();
1910 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1911 assert!(r.push_at_least(0, 5, &mut buf).is_ok());
1913 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1914 Vec::from_slice([BadBehavior(50), GoodBehavior(uint::MAX)]));
1915 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1917 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1918 Vec::from_slice([BadBehavior(1), GoodBehavior(1),
1919 BadBehavior(50), GoodBehavior(uint::MAX)]));
1920 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1921 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1923 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1924 Vec::from_slice([BadBehavior(uint::MAX)]));
1925 assert_eq!(r.push_at_least(1, 5, &mut buf).unwrap_err().kind, NoProgress);
1927 let mut r = MemReader::new(Vec::from_slice(b"hello, world!"));
1928 assert_eq!(r.push_at_least(5, 1, &mut buf).unwrap_err().kind, InvalidInput);