1 // Copyright 2013-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // FIXME: cover these topics:
12 // path, reader, writer, stream, raii (close not needed),
13 // stdio, print!, println!, file access, process spawning,
17 /*! I/O, including files, networking, timers, and processes
19 `std::io` provides Rust's basic I/O types,
20 for reading and writing to files, TCP, UDP,
21 and other types of sockets and pipes,
22 manipulating the file system, spawning processes and signal handling.
26 Some examples of obvious things you might want to do
28 * Read lines from stdin
33 for line in io::stdin().lines() {
34 print!("{}", line.unwrap());
38 * Read a complete file
43 let contents = File::open(&Path::new("message.txt")).read_to_end();
46 * Write a line to a file
49 # #![allow(unused_must_use)]
52 let mut file = File::create(&Path::new("message.txt"));
53 file.write(b"hello, file!\n");
55 # ::std::io::fs::unlink(&Path::new("message.txt"));
58 * Iterate over the lines of a file
61 use std::io::BufferedReader;
64 let path = Path::new("message.txt");
65 let mut file = BufferedReader::new(File::open(&path));
66 for line in file.lines() {
67 print!("{}", line.unwrap());
71 * Pull the lines of a file into a vector of strings
74 use std::io::BufferedReader;
77 let path = Path::new("message.txt");
78 let mut file = BufferedReader::new(File::open(&path));
79 let lines: Vec<String> = file.lines().map(|x| x.unwrap()).collect();
82 * Make a simple TCP client connection and request
85 # #![allow(unused_must_use)]
86 use std::io::TcpStream;
88 # // connection doesn't fail if a server is running on 8080
89 # // locally, we still want to be type checking this code, so lets
90 # // just stop it running (#11576)
92 let mut socket = TcpStream::connect("127.0.0.1", 8080).unwrap();
93 socket.write(b"GET / HTTP/1.0\n\n");
94 let response = socket.read_to_end();
98 * Make a simple TCP server
103 # #![allow(dead_code)]
104 use std::io::{TcpListener, TcpStream};
105 use std::io::{Acceptor, Listener};
107 let listener = TcpListener::bind("127.0.0.1", 80);
109 // bind the listener to the specified address
110 let mut acceptor = listener.listen();
112 fn handle_client(mut stream: TcpStream) {
114 # &mut stream; // silence unused mutability/variable warning
116 // accept connections and process them, spawning a new tasks for each one
117 for stream in acceptor.incoming() {
119 Err(e) => { /* connection failed */ }
120 Ok(stream) => spawn(proc() {
121 // connection succeeded
122 handle_client(stream)
127 // close the socket server
135 I/O is an area where nearly every operation can result in unexpected
136 errors. Errors should be painfully visible when they happen, and handling them
137 should be easy to work with. It should be convenient to handle specific I/O
138 errors, and it should also be convenient to not deal with I/O errors.
140 Rust's I/O employs a combination of techniques to reduce boilerplate
141 while still providing feedback about errors. The basic strategy:
143 * All I/O operations return `IoResult<T>` which is equivalent to
144 `Result<T, IoError>`. The `Result` type is defined in the `std::result`
146 * If the `Result` type goes unused, then the compiler will by default emit a
147 warning about the unused result. This is because `Result` has the
148 `#[must_use]` attribute.
149 * Common traits are implemented for `IoResult`, e.g.
150 `impl<R: Reader> Reader for IoResult<R>`, so that error values do not have
151 to be 'unwrapped' before use.
153 These features combine in the API to allow for expressions like
154 `File::create(&Path::new("diary.txt")).write(b"Met a girl.\n")`
155 without having to worry about whether "diary.txt" exists or whether
156 the write succeeds. As written, if either `new` or `write_line`
157 encounters an error then the result of the entire expression will
160 If you wanted to handle the error though you might write:
163 # #![allow(unused_must_use)]
166 match File::create(&Path::new("diary.txt")).write(b"Met a girl.\n") {
167 Ok(()) => (), // succeeded
168 Err(e) => println!("failed to write to my diary: {}", e),
171 # ::std::io::fs::unlink(&Path::new("diary.txt"));
174 So what actually happens if `create` encounters an error?
175 It's important to know that what `new` returns is not a `File`
176 but an `IoResult<File>`. If the file does not open, then `new` will simply
177 return `Err(..)`. Because there is an implementation of `Writer` (the trait
178 required ultimately required for types to implement `write_line`) there is no
179 need to inspect or unwrap the `IoResult<File>` and we simply call `write_line`
180 on it. If `new` returned an `Err(..)` then the followup call to `write_line`
181 will also return an error.
185 Explicit pattern matching on `IoResult`s can get quite verbose, especially
186 when performing many I/O operations. Some examples (like those above) are
187 alleviated with extra methods implemented on `IoResult`, but others have more
188 complex interdependencies among each I/O operation.
190 The `try!` macro from `std::macros` is provided as a method of early-return
191 inside `Result`-returning functions. It expands to an early-return on `Err`
192 and otherwise unwraps the contained `Ok` value.
194 If you wanted to read several `u32`s from a file and return their product:
197 use std::io::{File, IoResult};
199 fn file_product(p: &Path) -> IoResult<u32> {
200 let mut f = File::open(p);
201 let x1 = try!(f.read_le_u32());
202 let x2 = try!(f.read_le_u32());
207 match file_product(&Path::new("numbers.bin")) {
208 Ok(x) => println!("{}", x),
209 Err(e) => println!("Failed to read numbers!")
213 With `try!` in `file_product`, each `read_le_u32` need not be directly
214 concerned with error handling; instead its caller is responsible for
215 responding to errors that may occur while attempting to read the numbers.
220 #![deny(unused_must_use)]
223 use collections::Collection;
229 use ops::{BitOr, BitAnd, Sub, Not};
230 use option::{Option, Some, None};
233 use result::{Ok, Err, Result};
235 use slice::{Vector, MutableVector, ImmutableVector};
236 use str::{Str, StrSlice, StrAllocating};
240 use unicode::UnicodeChar;
244 pub use self::stdio::stdin;
245 pub use self::stdio::stdout;
246 pub use self::stdio::stderr;
247 pub use self::stdio::print;
248 pub use self::stdio::println;
250 pub use self::fs::File;
251 pub use self::timer::Timer;
252 pub use self::net::ip::IpAddr;
253 pub use self::net::tcp::TcpListener;
254 pub use self::net::tcp::TcpStream;
255 pub use self::net::udp::UdpStream;
256 pub use self::pipe::PipeStream;
257 pub use self::process::{Process, Command};
258 pub use self::tempfile::TempDir;
260 pub use self::mem::{MemReader, BufReader, MemWriter, BufWriter};
261 pub use self::buffered::{BufferedReader, BufferedWriter, BufferedStream,
263 pub use self::comm_adapters::{ChanReader, ChanWriter};
265 // this comes first to get the iotest! macro
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 static 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, 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, 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("the buffer is too short".to_string()),
571 ..standard_error(InvalidInput)
578 match self.read(buf.mut_slice_from(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("the buffer is too short".to_string()),
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_str(&mut self) -> IoResult<String> {
707 self.read_to_end().and_then(|s| {
708 match str::from_utf8(s.as_slice()) {
709 Some(s) => Ok(s.to_string()),
710 None => 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 Reader for Box<Reader> {
946 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> { self.read(buf) }
949 impl<'a> Reader for &'a mut Reader {
950 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> { self.read(buf) }
953 /// Returns a slice of `v` between `start` and `end`.
955 /// Similar to `slice()` except this function only bounds the slice on the
956 /// capacity of `v`, not the length.
960 /// Fails when `start` or `end` point outside the capacity of `v`, or when
962 // Private function here because we aren't sure if we want to expose this as
963 // API yet. If so, it should be a method on Vec.
964 unsafe fn slice_vec_capacity<'a, T>(v: &'a mut Vec<T>, start: uint, end: uint) -> &'a mut [T] {
968 assert!(start <= end);
969 assert!(end <= v.capacity());
971 data: v.as_ptr().offset(start as int),
976 /// A `RefReader` is a struct implementing `Reader` which contains a reference
977 /// to another reader. This is often useful when composing streams.
983 /// # fn process_input<R: Reader>(r: R) {}
986 /// use std::io::util::LimitReader;
988 /// let mut stream = io::stdin();
990 /// // Only allow the function to process at most one kilobyte of input
992 /// let stream = LimitReader::new(stream.by_ref(), 1024);
993 /// process_input(stream);
996 /// // 'stream' is still available for use here
1000 pub struct RefReader<'a, R> {
1001 /// The underlying reader which this is referencing
1005 impl<'a, R: Reader> Reader for RefReader<'a, R> {
1006 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> { self.inner.read(buf) }
1009 impl<'a, R: Buffer> Buffer for RefReader<'a, R> {
1010 fn fill_buf<'a>(&'a mut self) -> IoResult<&'a [u8]> { self.inner.fill_buf() }
1011 fn consume(&mut self, amt: uint) { self.inner.consume(amt) }
1014 fn extend_sign(val: u64, nbytes: uint) -> i64 {
1015 let shift = (8 - nbytes) * 8;
1016 (val << shift) as i64 >> shift
1019 /// A trait for objects which are byte-oriented streams. Writers are defined by
1020 /// one method, `write`. This function will block until the provided buffer of
1021 /// bytes has been entirely written, and it will return any failures which occur.
1023 /// Another commonly overridden method is the `flush` method for writers such as
1024 /// buffered writers.
1026 /// Writers are intended to be composable with one another. Many objects
1027 /// throughout the I/O and related libraries take and provide types which
1028 /// implement the `Writer` trait.
1030 /// Write the entirety of a given buffer
1034 /// If an error happens during the I/O operation, the error is returned as
1035 /// `Err`. Note that it is considered an error if the entire buffer could
1036 /// not be written, and if an error is returned then it is unknown how much
1037 /// data (if any) was actually written.
1038 fn write(&mut self, buf: &[u8]) -> IoResult<()>;
1040 /// Flush this output stream, ensuring that all intermediately buffered
1041 /// contents reach their destination.
1043 /// This is by default a no-op and implementers of the `Writer` trait should
1044 /// decide whether their stream needs to be buffered or not.
1045 fn flush(&mut self) -> IoResult<()> { Ok(()) }
1047 /// Writes a formatted string into this writer, returning any error
1050 /// This method is primarily used to interface with the `format_args!`
1051 /// macro, but it is rare that this should explicitly be called. The
1052 /// `write!` macro should be favored to invoke this method instead.
1056 /// This function will return any I/O error reported while formatting.
1057 fn write_fmt(&mut self, fmt: &fmt::Arguments) -> IoResult<()> {
1058 // Create a shim which translates a Writer to a FormatWriter and saves
1059 // off I/O errors. instead of discarding them
1060 struct Adaptor<'a, T> {
1062 error: IoResult<()>,
1064 impl<'a, T: Writer> fmt::FormatWriter for Adaptor<'a, T> {
1065 fn write(&mut self, bytes: &[u8]) -> fmt::Result {
1066 match self.inner.write(bytes) {
1069 self.error = Err(e);
1070 Err(fmt::WriteError)
1076 let mut output = Adaptor { inner: self, error: Ok(()) };
1077 match fmt::write(&mut output, fmt) {
1079 Err(..) => output.error
1083 /// Write a rust string into this sink.
1085 /// The bytes written will be the UTF-8 encoded version of the input string.
1086 /// If other encodings are desired, it is recommended to compose this stream
1087 /// with another performing the conversion, or to use `write` with a
1088 /// converted byte-array instead.
1090 fn write_str(&mut self, s: &str) -> IoResult<()> {
1091 self.write(s.as_bytes())
1094 /// Writes a string into this sink, and then writes a literal newline (`\n`)
1095 /// byte afterwards. Note that the writing of the newline is *not* atomic in
1096 /// the sense that the call to `write` is invoked twice (once with the
1097 /// string and once with a newline character).
1099 /// If other encodings or line ending flavors are desired, it is recommended
1100 /// that the `write` method is used specifically instead.
1102 fn write_line(&mut self, s: &str) -> IoResult<()> {
1103 self.write_str(s).and_then(|()| self.write(['\n' as u8]))
1106 /// Write a single char, encoded as UTF-8.
1108 fn write_char(&mut self, c: char) -> IoResult<()> {
1109 let mut buf = [0u8, ..4];
1110 let n = c.encode_utf8(buf.as_mut_slice());
1111 self.write(buf.slice_to(n))
1114 /// Write the result of passing n through `int::to_str_bytes`.
1116 fn write_int(&mut self, n: int) -> IoResult<()> {
1117 write!(self, "{:d}", n)
1120 /// Write the result of passing n through `uint::to_str_bytes`.
1122 fn write_uint(&mut self, n: uint) -> IoResult<()> {
1123 write!(self, "{:u}", n)
1126 /// Write a little-endian uint (number of bytes depends on system).
1128 fn write_le_uint(&mut self, n: uint) -> IoResult<()> {
1129 extensions::u64_to_le_bytes(n as u64, uint::BYTES, |v| self.write(v))
1132 /// Write a little-endian int (number of bytes depends on system).
1134 fn write_le_int(&mut self, n: int) -> IoResult<()> {
1135 extensions::u64_to_le_bytes(n as u64, int::BYTES, |v| self.write(v))
1138 /// Write a big-endian uint (number of bytes depends on system).
1140 fn write_be_uint(&mut self, n: uint) -> IoResult<()> {
1141 extensions::u64_to_be_bytes(n as u64, uint::BYTES, |v| self.write(v))
1144 /// Write a big-endian int (number of bytes depends on system).
1146 fn write_be_int(&mut self, n: int) -> IoResult<()> {
1147 extensions::u64_to_be_bytes(n as u64, int::BYTES, |v| self.write(v))
1150 /// Write a big-endian u64 (8 bytes).
1152 fn write_be_u64(&mut self, n: u64) -> IoResult<()> {
1153 extensions::u64_to_be_bytes(n, 8u, |v| self.write(v))
1156 /// Write a big-endian u32 (4 bytes).
1158 fn write_be_u32(&mut self, n: u32) -> IoResult<()> {
1159 extensions::u64_to_be_bytes(n as u64, 4u, |v| self.write(v))
1162 /// Write a big-endian u16 (2 bytes).
1164 fn write_be_u16(&mut self, n: u16) -> IoResult<()> {
1165 extensions::u64_to_be_bytes(n as u64, 2u, |v| self.write(v))
1168 /// Write a big-endian i64 (8 bytes).
1170 fn write_be_i64(&mut self, n: i64) -> IoResult<()> {
1171 extensions::u64_to_be_bytes(n as u64, 8u, |v| self.write(v))
1174 /// Write a big-endian i32 (4 bytes).
1176 fn write_be_i32(&mut self, n: i32) -> IoResult<()> {
1177 extensions::u64_to_be_bytes(n as u64, 4u, |v| self.write(v))
1180 /// Write a big-endian i16 (2 bytes).
1182 fn write_be_i16(&mut self, n: i16) -> IoResult<()> {
1183 extensions::u64_to_be_bytes(n as u64, 2u, |v| self.write(v))
1186 /// Write a big-endian IEEE754 double-precision floating-point (8 bytes).
1188 fn write_be_f64(&mut self, f: f64) -> IoResult<()> {
1190 self.write_be_u64(transmute(f))
1194 /// Write a big-endian IEEE754 single-precision floating-point (4 bytes).
1196 fn write_be_f32(&mut self, f: f32) -> IoResult<()> {
1198 self.write_be_u32(transmute(f))
1202 /// Write a little-endian u64 (8 bytes).
1204 fn write_le_u64(&mut self, n: u64) -> IoResult<()> {
1205 extensions::u64_to_le_bytes(n, 8u, |v| self.write(v))
1208 /// Write a little-endian u32 (4 bytes).
1210 fn write_le_u32(&mut self, n: u32) -> IoResult<()> {
1211 extensions::u64_to_le_bytes(n as u64, 4u, |v| self.write(v))
1214 /// Write a little-endian u16 (2 bytes).
1216 fn write_le_u16(&mut self, n: u16) -> IoResult<()> {
1217 extensions::u64_to_le_bytes(n as u64, 2u, |v| self.write(v))
1220 /// Write a little-endian i64 (8 bytes).
1222 fn write_le_i64(&mut self, n: i64) -> IoResult<()> {
1223 extensions::u64_to_le_bytes(n as u64, 8u, |v| self.write(v))
1226 /// Write a little-endian i32 (4 bytes).
1228 fn write_le_i32(&mut self, n: i32) -> IoResult<()> {
1229 extensions::u64_to_le_bytes(n as u64, 4u, |v| self.write(v))
1232 /// Write a little-endian i16 (2 bytes).
1234 fn write_le_i16(&mut self, n: i16) -> IoResult<()> {
1235 extensions::u64_to_le_bytes(n as u64, 2u, |v| self.write(v))
1238 /// Write a little-endian IEEE754 double-precision floating-point
1241 fn write_le_f64(&mut self, f: f64) -> IoResult<()> {
1243 self.write_le_u64(transmute(f))
1247 /// Write a little-endian IEEE754 single-precision floating-point
1250 fn write_le_f32(&mut self, f: f32) -> IoResult<()> {
1252 self.write_le_u32(transmute(f))
1256 /// Write a u8 (1 byte).
1258 fn write_u8(&mut self, n: u8) -> IoResult<()> {
1262 /// Write an i8 (1 byte).
1264 fn write_i8(&mut self, n: i8) -> IoResult<()> {
1265 self.write([n as u8])
1268 /// Creates a wrapper around a mutable reference to the writer.
1270 /// This is useful to allow applying wrappers while still
1271 /// retaining ownership of the original value.
1273 fn by_ref<'a>(&'a mut self) -> RefWriter<'a, Self> {
1274 RefWriter { inner: self }
1278 impl Writer for Box<Writer> {
1280 fn write(&mut self, buf: &[u8]) -> IoResult<()> { self.write(buf) }
1283 fn flush(&mut self) -> IoResult<()> { self.flush() }
1286 impl<'a> Writer for &'a mut Writer {
1288 fn write(&mut self, buf: &[u8]) -> IoResult<()> { self.write(buf) }
1291 fn flush(&mut self) -> IoResult<()> { self.flush() }
1294 /// A `RefWriter` is a struct implementing `Writer` which contains a reference
1295 /// to another writer. This is often useful when composing streams.
1301 /// # fn process_input<R: Reader>(r: R) {}
1303 /// use std::io::util::TeeReader;
1304 /// use std::io::{stdin, MemWriter};
1306 /// let mut output = MemWriter::new();
1309 /// // Don't give ownership of 'output' to the 'tee'. Instead we keep a
1310 /// // handle to it in the outer scope
1311 /// let mut tee = TeeReader::new(stdin(), output.by_ref());
1312 /// process_input(tee);
1315 /// println!("input processed: {}", output.unwrap());
1318 pub struct RefWriter<'a, W> {
1319 /// The underlying writer which this is referencing
1323 impl<'a, W: Writer> Writer for RefWriter<'a, W> {
1325 fn write(&mut self, buf: &[u8]) -> IoResult<()> { self.inner.write(buf) }
1328 fn flush(&mut self) -> IoResult<()> { self.inner.flush() }
1332 /// A Stream is a readable and a writable object. Data written is typically
1333 /// received by the object which reads receive data from.
1334 pub trait Stream: Reader + Writer { }
1336 impl<T: Reader + Writer> Stream for T {}
1338 /// An iterator that reads a line on each iteration,
1339 /// until `.read_line()` encounters `EndOfFile`.
1341 /// # Notes about the Iteration Protocol
1343 /// The `Lines` may yield `None` and thus terminate
1344 /// an iteration, but continue to yield elements if iteration
1345 /// is attempted again.
1349 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1350 /// is returned by the iterator and should be handled by the caller.
1351 pub struct Lines<'r, T> {
1355 impl<'r, T: Buffer> Iterator<IoResult<String>> for Lines<'r, T> {
1356 fn next(&mut self) -> Option<IoResult<String>> {
1357 match self.buffer.read_line() {
1358 Ok(x) => Some(Ok(x)),
1359 Err(IoError { kind: EndOfFile, ..}) => None,
1360 Err(y) => Some(Err(y))
1365 /// An iterator that reads a utf8-encoded character on each iteration,
1366 /// until `.read_char()` encounters `EndOfFile`.
1368 /// # Notes about the Iteration Protocol
1370 /// The `Chars` may yield `None` and thus terminate
1371 /// an iteration, but continue to yield elements if iteration
1372 /// is attempted again.
1376 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1377 /// is returned by the iterator and should be handled by the caller.
1378 pub struct Chars<'r, T> {
1382 impl<'r, T: Buffer> Iterator<IoResult<char>> for Chars<'r, T> {
1383 fn next(&mut self) -> Option<IoResult<char>> {
1384 match self.buffer.read_char() {
1385 Ok(x) => Some(Ok(x)),
1386 Err(IoError { kind: EndOfFile, ..}) => None,
1387 Err(y) => Some(Err(y))
1392 /// A Buffer is a type of reader which has some form of internal buffering to
1393 /// allow certain kinds of reading operations to be more optimized than others.
1394 /// This type extends the `Reader` trait with a few methods that are not
1395 /// possible to reasonably implement with purely a read interface.
1396 pub trait Buffer: Reader {
1397 /// Fills the internal buffer of this object, returning the buffer contents.
1398 /// Note that none of the contents will be "read" in the sense that later
1399 /// calling `read` may return the same contents.
1401 /// The `consume` function must be called with the number of bytes that are
1402 /// consumed from this buffer returned to ensure that the bytes are never
1407 /// This function will return an I/O error if the underlying reader was
1408 /// read, but returned an error. Note that it is not an error to return a
1409 /// 0-length buffer.
1410 fn fill_buf<'a>(&'a mut self) -> IoResult<&'a [u8]>;
1412 /// Tells this buffer that `amt` bytes have been consumed from the buffer,
1413 /// so they should no longer be returned in calls to `read`.
1414 fn consume(&mut self, amt: uint);
1416 /// Reads the next line of input, interpreted as a sequence of UTF-8
1417 /// encoded unicode codepoints. If a newline is encountered, then the
1418 /// newline is contained in the returned string.
1425 /// let mut reader = io::stdin();
1426 /// let input = reader.read_line().ok().unwrap_or("nothing".to_string());
1431 /// This function has the same error semantics as `read_until`:
1433 /// * All non-EOF errors will be returned immediately
1434 /// * If an error is returned previously consumed bytes are lost
1435 /// * EOF is only returned if no bytes have been read
1436 /// * Reach EOF may mean that the delimiter is not present in the return
1439 /// Additionally, this function can fail if the line of input read is not a
1440 /// valid UTF-8 sequence of bytes.
1441 fn read_line(&mut self) -> IoResult<String> {
1442 self.read_until('\n' as u8).and_then(|line|
1443 match str::from_utf8(line.as_slice()) {
1444 Some(s) => Ok(s.to_string()),
1445 None => Err(standard_error(InvalidInput)),
1450 /// Create an iterator that reads a line on each iteration until EOF.
1454 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1455 /// is returned by the iterator and should be handled by the caller.
1456 fn lines<'r>(&'r mut self) -> Lines<'r, Self> {
1457 Lines { buffer: self }
1460 /// Reads a sequence of bytes leading up to a specified delimiter. Once the
1461 /// specified byte is encountered, reading ceases and the bytes up to and
1462 /// including the delimiter are returned.
1466 /// If any I/O error is encountered other than EOF, the error is immediately
1467 /// returned. Note that this may discard bytes which have already been read,
1468 /// and those bytes will *not* be returned. It is recommended to use other
1469 /// methods if this case is worrying.
1471 /// If EOF is encountered, then this function will return EOF if 0 bytes
1472 /// have been read, otherwise the pending byte buffer is returned. This
1473 /// is the reason that the byte buffer returned may not always contain the
1475 fn read_until(&mut self, byte: u8) -> IoResult<Vec<u8>> {
1476 let mut res = Vec::new();
1481 let available = match self.fill_buf() {
1483 Err(ref e) if res.len() > 0 && e.kind == EndOfFile => {
1487 Err(e) => return Err(e)
1489 match available.iter().position(|&b| b == byte) {
1491 res.push_all(available.slice_to(i + 1));
1496 res.push_all(available);
1497 used = available.len();
1507 /// Reads the next utf8-encoded character from the underlying stream.
1511 /// If an I/O error occurs, or EOF, then this function will return `Err`.
1512 /// This function will also return error if the stream does not contain a
1513 /// valid utf-8 encoded codepoint as the next few bytes in the stream.
1514 fn read_char(&mut self) -> IoResult<char> {
1515 let first_byte = try!(self.read_byte());
1516 let width = str::utf8_char_width(first_byte);
1517 if width == 1 { return Ok(first_byte as char) }
1518 if width == 0 { return Err(standard_error(InvalidInput)) } // not utf8
1519 let mut buf = [first_byte, 0, 0, 0];
1522 while start < width {
1523 match try!(self.read(buf.mut_slice(start, width))) {
1524 n if n == width - start => break,
1525 n if n < width - start => { start += n; }
1526 _ => return Err(standard_error(InvalidInput)),
1530 match str::from_utf8(buf.slice_to(width)) {
1531 Some(s) => Ok(s.char_at(0)),
1532 None => Err(standard_error(InvalidInput))
1536 /// Create an iterator that reads a utf8-encoded character on each iteration
1541 /// Any error other than `EndOfFile` that is produced by the underlying Reader
1542 /// is returned by the iterator and should be handled by the caller.
1543 fn chars<'r>(&'r mut self) -> Chars<'r, Self> {
1544 Chars { buffer: self }
1548 /// When seeking, the resulting cursor is offset from a base by the offset given
1549 /// to the `seek` function. The base used is specified by this enumeration.
1550 pub enum SeekStyle {
1551 /// Seek from the beginning of the stream
1553 /// Seek from the end of the stream
1555 /// Seek from the current position
1559 /// An object implementing `Seek` internally has some form of cursor which can
1560 /// be moved within a stream of bytes. The stream typically has a fixed size,
1561 /// allowing seeking relative to either end.
1563 /// Return position of file cursor in the stream
1564 fn tell(&self) -> IoResult<u64>;
1566 /// Seek to an offset in a stream
1568 /// A successful seek clears the EOF indicator. Seeking beyond EOF is
1569 /// allowed, but seeking before position 0 is not allowed.
1573 /// * Seeking to a negative offset is considered an error
1574 /// * Seeking past the end of the stream does not modify the underlying
1575 /// stream, but the next write may cause the previous data to be filled in
1576 /// with a bit pattern.
1577 fn seek(&mut self, pos: i64, style: SeekStyle) -> IoResult<()>;
1580 /// A listener is a value that can consume itself to start listening for
1583 /// Doing so produces some sort of Acceptor.
1584 pub trait Listener<T, A: Acceptor<T>> {
1585 /// Spin up the listener and start queuing incoming connections
1589 /// Returns `Err` if this listener could not be bound to listen for
1590 /// connections. In all cases, this listener is consumed.
1591 fn listen(self) -> IoResult<A>;
1594 /// An acceptor is a value that presents incoming connections
1595 pub trait Acceptor<T> {
1596 /// Wait for and accept an incoming connection
1600 /// Returns `Err` if an I/O error is encountered.
1601 fn accept(&mut self) -> IoResult<T>;
1603 /// Create an iterator over incoming connection attempts.
1605 /// Note that I/O errors will be yielded by the iterator itself.
1606 fn incoming<'r>(&'r mut self) -> IncomingConnections<'r, Self> {
1607 IncomingConnections { inc: self }
1611 /// An infinite iterator over incoming connection attempts.
1612 /// Calling `next` will block the task until a connection is attempted.
1614 /// Since connection attempts can continue forever, this iterator always returns
1615 /// `Some`. The `Some` contains the `IoResult` representing whether the
1616 /// connection attempt was successful. A successful connection will be wrapped
1617 /// in `Ok`. A failed connection is represented as an `Err`.
1618 pub struct IncomingConnections<'a, A> {
1622 impl<'a, T, A: Acceptor<T>> Iterator<IoResult<T>> for IncomingConnections<'a, A> {
1623 fn next(&mut self) -> Option<IoResult<T>> {
1624 Some(self.inc.accept())
1628 /// Creates a standard error for a commonly used flavor of error. The `detail`
1629 /// field of the returned error will always be `None`.
1636 /// let eof = io::standard_error(io::EndOfFile);
1637 /// let einval = io::standard_error(io::InvalidInput);
1639 pub fn standard_error(kind: IoErrorKind) -> IoError {
1640 let desc = match kind {
1641 EndOfFile => "end of file",
1642 IoUnavailable => "I/O is unavailable",
1643 InvalidInput => "invalid input",
1644 OtherIoError => "unknown I/O error",
1645 FileNotFound => "file not found",
1646 PermissionDenied => "permission denied",
1647 ConnectionFailed => "connection failed",
1648 Closed => "stream is closed",
1649 ConnectionRefused => "connection refused",
1650 ConnectionReset => "connection reset",
1651 ConnectionAborted => "connection aborted",
1652 NotConnected => "not connected",
1653 BrokenPipe => "broken pipe",
1654 PathAlreadyExists => "file already exists",
1655 PathDoesntExist => "no such file",
1656 MismatchedFileTypeForOperation => "mismatched file type",
1657 ResourceUnavailable => "resource unavailable",
1658 TimedOut => "operation timed out",
1659 ShortWrite(..) => "short write",
1660 NoProgress => "no progress",
1669 /// A mode specifies how a file should be opened or created. These modes are
1670 /// passed to `File::open_mode` and are used to control where the file is
1671 /// positioned when it is initially opened.
1673 /// Opens a file positioned at the beginning.
1675 /// Opens a file positioned at EOF.
1677 /// Opens a file, truncating it if it already exists.
1681 /// Access permissions with which the file should be opened. `File`s
1682 /// opened with `Read` will return an error if written to.
1683 pub enum FileAccess {
1684 /// Read-only access, requests to write will result in an error
1686 /// Write-only access, requests to read will result in an error
1688 /// Read-write access, no requests are denied by default
1692 /// Different kinds of files which can be identified by a call to stat
1693 #[deriving(PartialEq, Show, Hash)]
1695 /// This is a normal file, corresponding to `S_IFREG`
1698 /// This file is a directory, corresponding to `S_IFDIR`
1701 /// This file is a named pipe, corresponding to `S_IFIFO`
1704 /// This file is a block device, corresponding to `S_IFBLK`
1707 /// This file is a symbolic link to another file, corresponding to `S_IFLNK`
1710 /// The type of this file is not recognized as one of the other categories
1714 /// A structure used to describe metadata information about a file. This
1715 /// structure is created through the `stat` method on a `Path`.
1722 /// let info = match Path::new("foo.txt").stat() {
1723 /// Ok(stat) => stat,
1724 /// Err(e) => fail!("couldn't read foo.txt: {}", e),
1727 /// println!("byte size: {}", info.size);
1731 pub struct FileStat {
1732 /// The size of the file, in bytes
1734 /// The kind of file this path points to (directory, file, pipe, etc.)
1736 /// The file permissions currently on the file
1737 pub perm: FilePermission,
1739 // FIXME(#10301): These time fields are pretty useless without an actual
1740 // time representation, what are the milliseconds relative
1743 /// The time that the file was created at, in platform-dependent
1746 /// The time that this file was last modified, in platform-dependent
1749 /// The time that this file was last accessed, in platform-dependent
1753 /// Information returned by stat() which is not guaranteed to be
1754 /// platform-independent. This information may be useful on some platforms,
1755 /// but it may have different meanings or no meaning at all on other
1758 /// Usage of this field is discouraged, but if access is desired then the
1759 /// fields are located here.
1761 pub unstable: UnstableFileStat,
1764 /// This structure represents all of the possible information which can be
1765 /// returned from a `stat` syscall which is not contained in the `FileStat`
1766 /// structure. This information is not necessarily platform independent, and may
1767 /// have different meanings or no meaning at all on some platforms.
1770 pub struct UnstableFileStat {
1771 /// The ID of the device containing the file.
1773 /// The file serial number.
1777 /// The number of hard links to this file.
1779 /// The user ID of the file.
1781 /// The group ID of the file.
1783 /// The optimal block size for I/O.
1785 /// The blocks allocated for this file.
1787 /// User-defined flags for the file.
1789 /// The file generation number.
1794 #[doc="A set of permissions for a file or directory is represented
1795 by a set of flags which are or'd together."]
1798 flags FilePermission: u32 {
1799 static UserRead = 0o400,
1800 static UserWrite = 0o200,
1801 static UserExecute = 0o100,
1802 static GroupRead = 0o040,
1803 static GroupWrite = 0o020,
1804 static GroupExecute = 0o010,
1805 static OtherRead = 0o004,
1806 static OtherWrite = 0o002,
1807 static OtherExecute = 0o001,
1809 static UserRWX = UserRead.bits | UserWrite.bits | UserExecute.bits,
1810 static GroupRWX = GroupRead.bits | GroupWrite.bits | GroupExecute.bits,
1811 static OtherRWX = OtherRead.bits | OtherWrite.bits | OtherExecute.bits,
1813 #[doc="Permissions for user owned files, equivalent to 0644 on
1814 unix-like systems."]
1815 static UserFile = UserRead.bits | UserWrite.bits | GroupRead.bits | OtherRead.bits,
1817 #[doc="Permissions for user owned directories, equivalent to 0755 on
1818 unix-like systems."]
1819 static UserDir = UserRWX.bits | GroupRead.bits | GroupExecute.bits |
1820 OtherRead.bits | OtherExecute.bits,
1822 #[doc="Permissions for user owned executables, equivalent to 0755
1823 on unix-like systems."]
1824 static UserExec = UserDir.bits,
1826 #[doc="All possible permissions enabled."]
1827 static AllPermissions = UserRWX.bits | GroupRWX.bits | OtherRWX.bits
1833 use super::{IoResult, Reader, MemReader, NoProgress, InvalidInput};
1837 #[deriving(Clone, PartialEq, Show)]
1838 enum BadReaderBehavior {
1843 struct BadReader<T> {
1845 behavior: Vec<BadReaderBehavior>,
1848 impl<T: Reader> BadReader<T> {
1849 fn new(r: T, behavior: Vec<BadReaderBehavior>) -> BadReader<T> {
1850 BadReader { behavior: behavior, r: r }
1854 impl<T: Reader> Reader for BadReader<T> {
1855 fn read(&mut self, buf: &mut [u8]) -> IoResult<uint> {
1856 let BadReader { ref mut behavior, ref mut r } = *self;
1858 if behavior.is_empty() {
1859 // fall back on good
1862 match behavior.as_mut_slice()[0] {
1863 GoodBehavior(0) => (),
1864 GoodBehavior(ref mut x) => {
1868 BadBehavior(0) => (),
1869 BadBehavior(ref mut x) => {
1880 fn test_read_at_least() {
1881 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1882 Vec::from_slice([GoodBehavior(uint::MAX)]));
1883 let mut buf = [0u8, ..5];
1884 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1885 assert!(r.read_exact(5).unwrap().len() == 5); // read_exact uses read_at_least
1886 assert!(r.read_at_least(0, buf).is_ok());
1888 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1889 Vec::from_slice([BadBehavior(50), GoodBehavior(uint::MAX)]));
1890 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1892 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1893 Vec::from_slice([BadBehavior(1), GoodBehavior(1),
1894 BadBehavior(50), GoodBehavior(uint::MAX)]));
1895 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1896 assert!(r.read_at_least(1, buf).unwrap() >= 1);
1898 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1899 Vec::from_slice([BadBehavior(uint::MAX)]));
1900 assert_eq!(r.read_at_least(1, buf).unwrap_err().kind, NoProgress);
1902 let mut r = MemReader::new(Vec::from_slice(b"hello, world!"));
1903 assert_eq!(r.read_at_least(5, buf).unwrap(), 5);
1904 assert_eq!(r.read_at_least(6, buf).unwrap_err().kind, InvalidInput);
1908 fn test_push_at_least() {
1909 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1910 Vec::from_slice([GoodBehavior(uint::MAX)]));
1911 let mut buf = Vec::new();
1912 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1913 assert!(r.push_at_least(0, 5, &mut buf).is_ok());
1915 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1916 Vec::from_slice([BadBehavior(50), GoodBehavior(uint::MAX)]));
1917 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1919 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1920 Vec::from_slice([BadBehavior(1), GoodBehavior(1),
1921 BadBehavior(50), GoodBehavior(uint::MAX)]));
1922 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1923 assert!(r.push_at_least(1, 5, &mut buf).unwrap() >= 1);
1925 let mut r = BadReader::new(MemReader::new(Vec::from_slice(b"hello, world!")),
1926 Vec::from_slice([BadBehavior(uint::MAX)]));
1927 assert_eq!(r.push_at_least(1, 5, &mut buf).unwrap_err().kind, NoProgress);
1929 let mut r = MemReader::new(Vec::from_slice(b"hello, world!"));
1930 assert_eq!(r.push_at_least(5, 1, &mut buf).unwrap_err().kind, InvalidInput);