src/libstd/sys/unix/fs.rs

   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.
   4 //
   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.
  10
  11 use core::prelude::*;
  12 use io::prelude::*;
  13 use os::unix::prelude::*;
  14
  15 use ffi::{CString, CStr, OsString, OsStr};
  16 use fmt;
  17 use io::{self, Error, ErrorKind, SeekFrom};
  18 use libc::{self, c_int, size_t, off_t, c_char, mode_t};
  19 use mem;
  20 use path::{Path, PathBuf};
  21 use ptr;
  22 use sync::Arc;
  23 use sys::fd::FileDesc;
  24 use sys::platform::raw;
  25 use sys::{c, cvt, cvt_r};
  26 use sys_common::{AsInner, FromInner};
  27 use vec::Vec;
  28
  29 pub struct File(FileDesc);
  30
  31 pub struct FileAttr {
  32     stat: raw::stat,
  33 }
  34
  35 pub struct ReadDir {
  36     dirp: Dir,
  37     root: Arc<PathBuf>,
  38 }
  39
  40 struct Dir(*mut libc::DIR);
  41
  42 unsafe impl Send for Dir {}
  43 unsafe impl Sync for Dir {}
  44
  45 pub struct DirEntry {
  46     buf: Vec<u8>, // actually *mut libc::dirent_t
  47     root: Arc<PathBuf>,
  48 }
  49
  50 #[derive(Clone)]
  51 pub struct OpenOptions {
  52     flags: c_int,
  53     read: bool,
  54     write: bool,
  55     mode: mode_t,
  56 }
  57
  58 #[derive(Clone, PartialEq, Eq, Debug)]
  59 pub struct FilePermissions { mode: mode_t }
  60
  61 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
  62 pub struct FileType { mode: mode_t }
  63
  64 pub struct DirBuilder { mode: mode_t }
  65
  66 impl FileAttr {
  67     pub fn size(&self) -> u64 { self.stat.st_size as u64 }
  68     pub fn perm(&self) -> FilePermissions {
  69         FilePermissions { mode: (self.stat.st_mode as mode_t) & 0o777 }
  70     }
  71
  72     pub fn file_type(&self) -> FileType {
  73         FileType { mode: self.stat.st_mode as mode_t }
  74     }
  75 }
  76
  77 impl AsInner<raw::stat> for FileAttr {
  78     fn as_inner(&self) -> &raw::stat { &self.stat }
  79 }
  80
  81 /// OS-specific extension methods for `fs::Metadata`
  82 #[stable(feature = "metadata_ext", since = "1.1.0")]
  83 pub trait MetadataExt {
  84     /// Gain a reference to the underlying `stat` structure which contains the
  85     /// raw information returned by the OS.
  86     ///
  87     /// The contents of the returned `stat` are **not** consistent across Unix
  88     /// platforms. The `os::unix::fs::MetadataExt` trait contains the cross-Unix
  89     /// abstractions contained within the raw stat.
  90     #[stable(feature = "metadata_ext", since = "1.1.0")]
  91     fn as_raw_stat(&self) -> &raw::stat;
  92 }
  93
  94 #[stable(feature = "metadata_ext", since = "1.1.0")]
  95 impl MetadataExt for ::fs::Metadata {
  96     fn as_raw_stat(&self) -> &raw::stat { &self.as_inner().stat }
  97 }
  98
  99 impl FilePermissions {
 100     pub fn readonly(&self) -> bool { self.mode & 0o222 == 0 }
 101     pub fn set_readonly(&mut self, readonly: bool) {
 102         if readonly {
 103             self.mode &= !0o222;
 104         } else {
 105             self.mode |= 0o222;
 106         }
 107     }
 108     pub fn mode(&self) -> raw::mode_t { self.mode }
 109 }
 110
 111 impl FileType {
 112     pub fn is_dir(&self) -> bool { self.is(libc::S_IFDIR) }
 113     pub fn is_file(&self) -> bool { self.is(libc::S_IFREG) }
 114     pub fn is_symlink(&self) -> bool { self.is(libc::S_IFLNK) }
 115
 116     pub fn is(&self, mode: mode_t) -> bool { self.mode & libc::S_IFMT == mode }
 117 }
 118
 119 impl FromInner<raw::mode_t> for FilePermissions {
 120     fn from_inner(mode: raw::mode_t) -> FilePermissions {
 121         FilePermissions { mode: mode as mode_t }
 122     }
 123 }
 124
 125 impl Iterator for ReadDir {
 126     type Item = io::Result<DirEntry>;
 127
 128     fn next(&mut self) -> Option<io::Result<DirEntry>> {
 129         extern {
 130             fn rust_dirent_t_size() -> c_int;
 131         }
 132
 133         let mut buf: Vec<u8> = Vec::with_capacity(unsafe {
 134             rust_dirent_t_size() as usize
 135         });
 136         let ptr = buf.as_mut_ptr() as *mut libc::dirent_t;
 137
 138         let mut entry_ptr = ptr::null_mut();
 139         loop {
 140             if unsafe { libc::readdir_r(self.dirp.0, ptr, &mut entry_ptr) != 0 } {
 141                 return Some(Err(Error::last_os_error()))
 142             }
 143             if entry_ptr.is_null() {
 144                 return None
 145             }
 146
 147             let entry = DirEntry {
 148                 buf: buf,
 149                 root: self.root.clone()
 150             };
 151             if entry.name_bytes() == b"." || entry.name_bytes() == b".." {
 152                 buf = entry.buf;
 153             } else {
 154                 return Some(Ok(entry))
 155             }
 156         }
 157     }
 158 }
 159
 160 impl Drop for Dir {
 161     fn drop(&mut self) {
 162         let r = unsafe { libc::closedir(self.0) };
 163         debug_assert_eq!(r, 0);
 164     }
 165 }
 166
 167 impl DirEntry {
 168     pub fn path(&self) -> PathBuf {
 169         self.root.join(<OsStr as OsStrExt>::from_bytes(self.name_bytes()))
 170     }
 171
 172     pub fn file_name(&self) -> OsString {
 173         OsStr::from_bytes(self.name_bytes()).to_os_string()
 174     }
 175
 176     pub fn metadata(&self) -> io::Result<FileAttr> {
 177         lstat(&self.path())
 178     }
 179
 180     pub fn file_type(&self) -> io::Result<FileType> {
 181         extern {
 182             fn rust_dir_get_mode(ptr: *mut libc::dirent_t) -> c_int;
 183         }
 184         unsafe {
 185             match rust_dir_get_mode(self.dirent()) {
 186                 -1 => lstat(&self.path()).map(|m| m.file_type()),
 187                 n => Ok(FileType { mode: n as mode_t }),
 188             }
 189         }
 190     }
 191
 192     pub fn ino(&self) -> raw::ino_t {
 193         extern {
 194             fn rust_dir_get_ino(ptr: *mut libc::dirent_t) -> raw::ino_t;
 195         }
 196         unsafe { rust_dir_get_ino(self.dirent()) }
 197     }
 198
 199     fn name_bytes(&self) -> &[u8] {
 200         extern {
 201             fn rust_list_dir_val(ptr: *mut libc::dirent_t) -> *const c_char;
 202         }
 203         unsafe {
 204             CStr::from_ptr(rust_list_dir_val(self.dirent())).to_bytes()
 205         }
 206     }
 207
 208     fn dirent(&self) -> *mut libc::dirent_t {
 209         self.buf.as_ptr() as *mut _
 210     }
 211 }
 212
 213 impl OpenOptions {
 214     pub fn new() -> OpenOptions {
 215         OpenOptions {
 216             flags: 0,
 217             read: false,
 218             write: false,
 219             mode: 0o666,
 220         }
 221     }
 222
 223     pub fn read(&mut self, read: bool) {
 224         self.read = read;
 225     }
 226
 227     pub fn write(&mut self, write: bool) {
 228         self.write = write;
 229     }
 230
 231     pub fn append(&mut self, append: bool) {
 232         self.flag(libc::O_APPEND, append);
 233     }
 234
 235     pub fn truncate(&mut self, truncate: bool) {
 236         self.flag(libc::O_TRUNC, truncate);
 237     }
 238
 239     pub fn create(&mut self, create: bool) {
 240         self.flag(libc::O_CREAT, create);
 241     }
 242
 243     pub fn mode(&mut self, mode: raw::mode_t) {
 244         self.mode = mode as mode_t;
 245     }
 246
 247     fn flag(&mut self, bit: c_int, on: bool) {
 248         if on {
 249             self.flags |= bit;
 250         } else {
 251             self.flags &= !bit;
 252         }
 253     }
 254 }
 255
 256 impl File {
 257     pub fn open(path: &Path, opts: &OpenOptions) -> io::Result<File> {
 258         let path = try!(cstr(path));
 259         File::open_c(&path, opts)
 260     }
 261
 262     pub fn open_c(path: &CStr, opts: &OpenOptions) -> io::Result<File> {
 263         let flags = opts.flags | match (opts.read, opts.write) {
 264             (true, true) => libc::O_RDWR,
 265             (false, true) => libc::O_WRONLY,
 266             (true, false) |
 267             (false, false) => libc::O_RDONLY,
 268         };
 269         let fd = try!(cvt_r(|| unsafe {
 270             libc::open(path.as_ptr(), flags, opts.mode)
 271         }));
 272         let fd = FileDesc::new(fd);
 273         fd.set_cloexec();
 274         Ok(File(fd))
 275     }
 276
 277     pub fn file_attr(&self) -> io::Result<FileAttr> {
 278         let mut stat: raw::stat = unsafe { mem::zeroed() };
 279         try!(cvt(unsafe {
 280             libc::fstat(self.0.raw(), &mut stat as *mut _ as *mut _)
 281         }));
 282         Ok(FileAttr { stat: stat })
 283     }
 284
 285     pub fn fsync(&self) -> io::Result<()> {
 286         try!(cvt_r(|| unsafe { libc::fsync(self.0.raw()) }));
 287         Ok(())
 288     }
 289
 290     pub fn datasync(&self) -> io::Result<()> {
 291         try!(cvt_r(|| unsafe { os_datasync(self.0.raw()) }));
 292         return Ok(());
 293
 294         #[cfg(any(target_os = "macos", target_os = "ios"))]
 295         unsafe fn os_datasync(fd: c_int) -> c_int {
 296             libc::fcntl(fd, libc::F_FULLFSYNC)
 297         }
 298         #[cfg(target_os = "linux")]
 299         unsafe fn os_datasync(fd: c_int) -> c_int { libc::fdatasync(fd) }
 300         #[cfg(not(any(target_os = "macos",
 301                       target_os = "ios",
 302                       target_os = "linux")))]
 303         unsafe fn os_datasync(fd: c_int) -> c_int { libc::fsync(fd) }
 304     }
 305
 306     pub fn truncate(&self, size: u64) -> io::Result<()> {
 307         try!(cvt_r(|| unsafe {
 308             libc::ftruncate(self.0.raw(), size as libc::off_t)
 309         }));
 310         Ok(())
 311     }
 312
 313     pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
 314         self.0.read(buf)
 315     }
 316
 317     pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
 318         self.0.write(buf)
 319     }
 320
 321     pub fn flush(&self) -> io::Result<()> { Ok(()) }
 322
 323     pub fn seek(&self, pos: SeekFrom) -> io::Result<u64> {
 324         let (whence, pos) = match pos {
 325             SeekFrom::Start(off) => (libc::SEEK_SET, off as off_t),
 326             SeekFrom::End(off) => (libc::SEEK_END, off as off_t),
 327             SeekFrom::Current(off) => (libc::SEEK_CUR, off as off_t),
 328         };
 329         let n = try!(cvt(unsafe { libc::lseek(self.0.raw(), pos, whence) }));
 330         Ok(n as u64)
 331     }
 332
 333     pub fn fd(&self) -> &FileDesc { &self.0 }
 334
 335     pub fn into_fd(self) -> FileDesc { self.0 }
 336 }
 337
 338 impl DirBuilder {
 339     pub fn new() -> DirBuilder {
 340         DirBuilder { mode: 0o777 }
 341     }
 342
 343     pub fn mkdir(&self, p: &Path) -> io::Result<()> {
 344         let p = try!(cstr(p));
 345         try!(cvt(unsafe { libc::mkdir(p.as_ptr(), self.mode) }));
 346         Ok(())
 347     }
 348
 349     pub fn set_mode(&mut self, mode: mode_t) {
 350         self.mode = mode;
 351     }
 352 }
 353
 354 fn cstr(path: &Path) -> io::Result<CString> {
 355     path.as_os_str().to_cstring().ok_or(
 356         io::Error::new(io::ErrorKind::InvalidInput, "path contained a null"))
 357 }
 358
 359 impl FromInner<c_int> for File {
 360     fn from_inner(fd: c_int) -> File {
 361         File(FileDesc::new(fd))
 362     }
 363 }
 364
 365 impl fmt::Debug for File {
 366     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 367         #[cfg(target_os = "linux")]
 368         fn get_path(fd: c_int) -> Option<PathBuf> {
 369             use string::ToString;
 370             let mut p = PathBuf::from("/proc/self/fd");
 371             p.push(&fd.to_string());
 372             readlink(&p).ok()
 373         }
 374
 375         #[cfg(target_os = "macos")]
 376         fn get_path(fd: c_int) -> Option<PathBuf> {
 377             let mut buf = vec![0;libc::PATH_MAX as usize];
 378             let n = unsafe { libc::fcntl(fd, libc::F_GETPATH, buf.as_ptr()) };
 379             if n == -1 {
 380                 return None;
 381             }
 382             let l = buf.iter().position(|&c| c == 0).unwrap();
 383             buf.truncate(l as usize);
 384             Some(PathBuf::from(OsString::from_vec(buf)))
 385         }
 386
 387         #[cfg(not(any(target_os = "linux", target_os = "macos")))]
 388         fn get_path(_fd: c_int) -> Option<PathBuf> {
 389             // FIXME(#24570): implement this for other Unix platforms
 390             None
 391         }
 392
 393         #[cfg(any(target_os = "linux", target_os = "macos"))]
 394         fn get_mode(fd: c_int) -> Option<(bool, bool)> {
 395             let mode = unsafe { libc::fcntl(fd, libc::F_GETFL) };
 396             if mode == -1 {
 397                 return None;
 398             }
 399             match mode & libc::O_ACCMODE {
 400                 libc::O_RDONLY => Some((true, false)),
 401                 libc::O_RDWR => Some((true, true)),
 402                 libc::O_WRONLY => Some((false, true)),
 403                 _ => None
 404             }
 405         }
 406
 407         #[cfg(not(any(target_os = "linux", target_os = "macos")))]
 408         fn get_mode(_fd: c_int) -> Option<(bool, bool)> {
 409             // FIXME(#24570): implement this for other Unix platforms
 410             None
 411         }
 412
 413         let fd = self.0.raw();
 414         let mut b = f.debug_struct("File");
 415         b.field("fd", &fd);
 416         if let Some(path) = get_path(fd) {
 417             b.field("path", &path);
 418         }
 419         if let Some((read, write)) = get_mode(fd) {
 420             b.field("read", &read).field("write", &write);
 421         }
 422         b.finish()
 423     }
 424 }
 425
 426 pub fn readdir(p: &Path) -> io::Result<ReadDir> {
 427     let root = Arc::new(p.to_path_buf());
 428     let p = try!(cstr(p));
 429     unsafe {
 430         let ptr = libc::opendir(p.as_ptr());
 431         if ptr.is_null() {
 432             Err(Error::last_os_error())
 433         } else {
 434             Ok(ReadDir { dirp: Dir(ptr), root: root })
 435         }
 436     }
 437 }
 438
 439 pub fn unlink(p: &Path) -> io::Result<()> {
 440     let p = try!(cstr(p));
 441     try!(cvt(unsafe { libc::unlink(p.as_ptr()) }));
 442     Ok(())
 443 }
 444
 445 pub fn rename(old: &Path, new: &Path) -> io::Result<()> {
 446     let old = try!(cstr(old));
 447     let new = try!(cstr(new));
 448     try!(cvt(unsafe { libc::rename(old.as_ptr(), new.as_ptr()) }));
 449     Ok(())
 450 }
 451
 452 pub fn set_perm(p: &Path, perm: FilePermissions) -> io::Result<()> {
 453     let p = try!(cstr(p));
 454     try!(cvt_r(|| unsafe { libc::chmod(p.as_ptr(), perm.mode) }));
 455     Ok(())
 456 }
 457
 458 pub fn rmdir(p: &Path) -> io::Result<()> {
 459     let p = try!(cstr(p));
 460     try!(cvt(unsafe { libc::rmdir(p.as_ptr()) }));
 461     Ok(())
 462 }
 463
 464 pub fn readlink(p: &Path) -> io::Result<PathBuf> {
 465     let c_path = try!(cstr(p));
 466     let p = c_path.as_ptr();
 467     let mut len = unsafe { libc::pathconf(p as *mut _, libc::_PC_NAME_MAX) };
 468     if len < 0 {
 469         len = 1024; // FIXME: read PATH_MAX from C ffi?
 470     }
 471     let mut buf: Vec<u8> = Vec::with_capacity(len as usize);
 472     unsafe {
 473         let n = try!(cvt({
 474             libc::readlink(p, buf.as_ptr() as *mut c_char, len as size_t)
 475         }));
 476         buf.set_len(n as usize);
 477     }
 478     Ok(PathBuf::from(OsString::from_vec(buf)))
 479 }
 480
 481 pub fn symlink(src: &Path, dst: &Path) -> io::Result<()> {
 482     let src = try!(cstr(src));
 483     let dst = try!(cstr(dst));
 484     try!(cvt(unsafe { libc::symlink(src.as_ptr(), dst.as_ptr()) }));
 485     Ok(())
 486 }
 487
 488 pub fn link(src: &Path, dst: &Path) -> io::Result<()> {
 489     let src = try!(cstr(src));
 490     let dst = try!(cstr(dst));
 491     try!(cvt(unsafe { libc::link(src.as_ptr(), dst.as_ptr()) }));
 492     Ok(())
 493 }
 494
 495 pub fn stat(p: &Path) -> io::Result<FileAttr> {
 496     let p = try!(cstr(p));
 497     let mut stat: raw::stat = unsafe { mem::zeroed() };
 498     try!(cvt(unsafe {
 499         libc::stat(p.as_ptr(), &mut stat as *mut _ as *mut _)
 500     }));
 501     Ok(FileAttr { stat: stat })
 502 }
 503
 504 pub fn lstat(p: &Path) -> io::Result<FileAttr> {
 505     let p = try!(cstr(p));
 506     let mut stat: raw::stat = unsafe { mem::zeroed() };
 507     try!(cvt(unsafe {
 508         libc::lstat(p.as_ptr(), &mut stat as *mut _ as *mut _)
 509     }));
 510     Ok(FileAttr { stat: stat })
 511 }
 512
 513 pub fn utimes(p: &Path, atime: u64, mtime: u64) -> io::Result<()> {
 514     let p = try!(cstr(p));
 515     let buf = [super::ms_to_timeval(atime), super::ms_to_timeval(mtime)];
 516     try!(cvt(unsafe { c::utimes(p.as_ptr(), buf.as_ptr()) }));
 517     Ok(())
 518 }
 519
 520 pub fn canonicalize(p: &Path) -> io::Result<PathBuf> {
 521     let path = try!(CString::new(p.as_os_str().as_bytes()));
 522     let mut buf = vec![0u8; 16 * 1024];
 523     unsafe {
 524         let r = c::realpath(path.as_ptr(), buf.as_mut_ptr() as *mut _);
 525         if r.is_null() {
 526             return Err(io::Error::last_os_error())
 527         }
 528     }
 529     let p = buf.iter().position(|i| *i == 0).unwrap();
 530     buf.truncate(p);
 531     Ok(PathBuf::from(OsString::from_vec(buf)))
 532 }
 533
 534 pub fn copy(from: &Path, to: &Path) -> io::Result<u64> {
 535     use fs::{File, PathExt, set_permissions};
 536     if !from.is_file() {
 537         return Err(Error::new(ErrorKind::InvalidInput,
 538                               "the source path is not an existing file"))
 539     }
 540
 541     let mut reader = try!(File::open(from));
 542     let mut writer = try!(File::create(to));
 543     let perm = try!(reader.metadata()).permissions();
 544
 545     let ret = try!(io::copy(&mut reader, &mut writer));
 546     try!(set_permissions(to, perm));
 547     Ok(ret)
 548 }