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 prelude::v1::*;
  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, 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::time::SystemTime;
  25 use sys::{cvt, cvt_r};
  26 use sys_common::{AsInner, FromInner};
  27
  28 #[cfg(any(target_os = "linux", target_os = "emscripten"))]
  29 use libc::{stat64, fstat64, lstat64, off64_t, ftruncate64, lseek64, dirent64, readdir64_r, open64};
  30 #[cfg(target_os = "android")]
  31 use libc::{stat as stat64, fstat as fstat64, lstat as lstat64, off64_t, ftruncate64, lseek64,
  32            dirent as dirent64, open as open64};
  33 #[cfg(not(any(target_os = "linux",
  34               target_os = "emscripten",
  35               target_os = "android")))]
  36 use libc::{stat as stat64, fstat as fstat64, lstat as lstat64, off_t as off64_t,
  37            ftruncate as ftruncate64, lseek as lseek64, dirent as dirent64, open as open64};
  38 #[cfg(not(any(target_os = "linux",
  39               target_os = "emscripten",
  40               target_os = "solaris")))]
  41 use libc::{readdir_r as readdir64_r};
  42
  43 pub struct File(FileDesc);
  44
  45 #[derive(Clone)]
  46 pub struct FileAttr {
  47     stat: stat64,
  48 }
  49
  50 pub struct ReadDir {
  51     dirp: Dir,
  52     root: Arc<PathBuf>,
  53 }
  54
  55 struct Dir(*mut libc::DIR);
  56
  57 unsafe impl Send for Dir {}
  58 unsafe impl Sync for Dir {}
  59
  60 pub struct DirEntry {
  61     entry: dirent64,
  62     root: Arc<PathBuf>,
  63     // We need to store an owned copy of the directory name
  64     // on Solaris because a) it uses a zero-length array to
  65     // store the name, b) its lifetime between readdir calls
  66     // is not guaranteed.
  67     #[cfg(target_os = "solaris")]
  68     name: Box<[u8]>
  69 }
  70
  71 #[derive(Clone)]
  72 pub struct OpenOptions {
  73     // generic
  74     read: bool,
  75     write: bool,
  76     append: bool,
  77     truncate: bool,
  78     create: bool,
  79     create_new: bool,
  80     // system-specific
  81     custom_flags: i32,
  82     mode: mode_t,
  83 }
  84
  85 #[derive(Clone, PartialEq, Eq, Debug)]
  86 pub struct FilePermissions { mode: mode_t }
  87
  88 #[derive(Copy, Clone, PartialEq, Eq, Hash)]
  89 pub struct FileType { mode: mode_t }
  90
  91 pub struct DirBuilder { mode: mode_t }
  92
  93 impl FileAttr {
  94     pub fn size(&self) -> u64 { self.stat.st_size as u64 }
  95     pub fn perm(&self) -> FilePermissions {
  96         FilePermissions { mode: (self.stat.st_mode as mode_t) & 0o777 }
  97     }
  98
  99     pub fn file_type(&self) -> FileType {
 100         FileType { mode: self.stat.st_mode as mode_t }
 101     }
 102 }
 103
 104 #[cfg(any(target_os = "ios", target_os = "macos"))]
 105 // FIXME: update SystemTime to store a timespec and don't lose precision
 106 impl FileAttr {
 107     pub fn modified(&self) -> io::Result<SystemTime> {
 108         Ok(SystemTime::from(libc::timeval {
 109             tv_sec: self.stat.st_mtime,
 110             tv_usec: (self.stat.st_mtime_nsec / 1000) as libc::suseconds_t,
 111         }))
 112     }
 113
 114     pub fn accessed(&self) -> io::Result<SystemTime> {
 115         Ok(SystemTime::from(libc::timeval {
 116             tv_sec: self.stat.st_atime,
 117             tv_usec: (self.stat.st_atime_nsec / 1000) as libc::suseconds_t,
 118         }))
 119     }
 120
 121     pub fn created(&self) -> io::Result<SystemTime> {
 122         Ok(SystemTime::from(libc::timeval {
 123             tv_sec: self.stat.st_birthtime,
 124             tv_usec: (self.stat.st_birthtime_nsec / 1000) as libc::suseconds_t,
 125         }))
 126     }
 127 }
 128
 129 #[cfg(target_os = "netbsd")]
 130 impl FileAttr {
 131     pub fn modified(&self) -> io::Result<SystemTime> {
 132         Ok(SystemTime::from(libc::timespec {
 133             tv_sec: self.stat.st_mtime as libc::time_t,
 134             tv_nsec: self.stat.st_mtimensec as libc::c_long,
 135         }))
 136     }
 137
 138     pub fn accessed(&self) -> io::Result<SystemTime> {
 139         Ok(SystemTime::from(libc::timespec {
 140             tv_sec: self.stat.st_atime as libc::time_t,
 141             tv_nsec: self.stat.st_atimensec as libc::c_long,
 142         }))
 143     }
 144
 145     pub fn created(&self) -> io::Result<SystemTime> {
 146         Ok(SystemTime::from(libc::timespec {
 147             tv_sec: self.stat.st_birthtime as libc::time_t,
 148             tv_nsec: self.stat.st_birthtimensec as libc::c_long,
 149         }))
 150     }
 151 }
 152
 153 #[cfg(not(any(target_os = "ios", target_os = "macos", target_os = "netbsd")))]
 154 impl FileAttr {
 155     pub fn modified(&self) -> io::Result<SystemTime> {
 156         Ok(SystemTime::from(libc::timespec {
 157             tv_sec: self.stat.st_mtime as libc::time_t,
 158             tv_nsec: self.stat.st_mtime_nsec as libc::c_long,
 159         }))
 160     }
 161
 162     pub fn accessed(&self) -> io::Result<SystemTime> {
 163         Ok(SystemTime::from(libc::timespec {
 164             tv_sec: self.stat.st_atime as libc::time_t,
 165             tv_nsec: self.stat.st_atime_nsec as libc::c_long,
 166         }))
 167     }
 168
 169     #[cfg(any(target_os = "bitrig",
 170               target_os = "freebsd",
 171               target_os = "openbsd"))]
 172     pub fn created(&self) -> io::Result<SystemTime> {
 173         Ok(SystemTime::from(libc::timespec {
 174             tv_sec: self.stat.st_birthtime as libc::time_t,
 175             tv_nsec: self.stat.st_birthtime_nsec as libc::c_long,
 176         }))
 177     }
 178
 179     #[cfg(not(any(target_os = "bitrig",
 180                   target_os = "freebsd",
 181                   target_os = "openbsd")))]
 182     pub fn created(&self) -> io::Result<SystemTime> {
 183         Err(io::Error::new(io::ErrorKind::Other,
 184                            "creation time is not available on this platform \
 185                             currently"))
 186     }
 187 }
 188
 189 impl AsInner<stat64> for FileAttr {
 190     fn as_inner(&self) -> &stat64 { &self.stat }
 191 }
 192
 193 impl FilePermissions {
 194     pub fn readonly(&self) -> bool { self.mode & 0o222 == 0 }
 195     pub fn set_readonly(&mut self, readonly: bool) {
 196         if readonly {
 197             self.mode &= !0o222;
 198         } else {
 199             self.mode |= 0o222;
 200         }
 201     }
 202     pub fn mode(&self) -> u32 { self.mode as u32 }
 203 }
 204
 205 impl FileType {
 206     pub fn is_dir(&self) -> bool { self.is(libc::S_IFDIR) }
 207     pub fn is_file(&self) -> bool { self.is(libc::S_IFREG) }
 208     pub fn is_symlink(&self) -> bool { self.is(libc::S_IFLNK) }
 209
 210     pub fn is(&self, mode: mode_t) -> bool { self.mode & libc::S_IFMT == mode }
 211 }
 212
 213 impl FromInner<u32> for FilePermissions {
 214     fn from_inner(mode: u32) -> FilePermissions {
 215         FilePermissions { mode: mode as mode_t }
 216     }
 217 }
 218
 219 impl Iterator for ReadDir {
 220     type Item = io::Result<DirEntry>;
 221
 222     #[cfg(target_os = "solaris")]
 223     fn next(&mut self) -> Option<io::Result<DirEntry>> {
 224         unsafe {
 225             loop {
 226                 // Although readdir_r(3) would be a correct function to use here because
 227                 // of the thread safety, on Illumos the readdir(3C) function is safe to use
 228                 // in threaded applications and it is generally preferred over the
 229                 // readdir_r(3C) function.
 230                 let entry_ptr = libc::readdir(self.dirp.0);
 231                 if entry_ptr.is_null() {
 232                     return None
 233                 }
 234
 235                 let name = (*entry_ptr).d_name.as_ptr();
 236                 let namelen = libc::strlen(name) as usize;
 237
 238                 let ret = DirEntry {
 239                     entry: *entry_ptr,
 240                     name: ::slice::from_raw_parts(name as *const u8,
 241                                                   namelen as usize).to_owned().into_boxed_slice(),
 242                     root: self.root.clone()
 243                 };
 244                 if ret.name_bytes() != b"." && ret.name_bytes() != b".." {
 245                     return Some(Ok(ret))
 246                 }
 247             }
 248         }
 249     }
 250
 251     #[cfg(not(target_os = "solaris"))]
 252     fn next(&mut self) -> Option<io::Result<DirEntry>> {
 253         unsafe {
 254             let mut ret = DirEntry {
 255                 entry: mem::zeroed(),
 256                 root: self.root.clone()
 257             };
 258             let mut entry_ptr = ptr::null_mut();
 259             loop {
 260                 if readdir64_r(self.dirp.0, &mut ret.entry, &mut entry_ptr) != 0 {
 261                     return Some(Err(Error::last_os_error()))
 262                 }
 263                 if entry_ptr.is_null() {
 264                     return None
 265                 }
 266                 if ret.name_bytes() != b"." && ret.name_bytes() != b".." {
 267                     return Some(Ok(ret))
 268                 }
 269             }
 270         }
 271     }
 272 }
 273
 274 impl Drop for Dir {
 275     fn drop(&mut self) {
 276         let r = unsafe { libc::closedir(self.0) };
 277         debug_assert_eq!(r, 0);
 278     }
 279 }
 280
 281 impl DirEntry {
 282     pub fn path(&self) -> PathBuf {
 283         self.root.join(OsStr::from_bytes(self.name_bytes()))
 284     }
 285
 286     pub fn file_name(&self) -> OsString {
 287         OsStr::from_bytes(self.name_bytes()).to_os_string()
 288     }
 289
 290     pub fn metadata(&self) -> io::Result<FileAttr> {
 291         lstat(&self.path())
 292     }
 293
 294     #[cfg(target_os = "solaris")]
 295     pub fn file_type(&self) -> io::Result<FileType> {
 296         stat(&self.path()).map(|m| m.file_type())
 297     }
 298
 299     #[cfg(not(target_os = "solaris"))]
 300     pub fn file_type(&self) -> io::Result<FileType> {
 301         match self.entry.d_type {
 302             libc::DT_CHR => Ok(FileType { mode: libc::S_IFCHR }),
 303             libc::DT_FIFO => Ok(FileType { mode: libc::S_IFIFO }),
 304             libc::DT_LNK => Ok(FileType { mode: libc::S_IFLNK }),
 305             libc::DT_REG => Ok(FileType { mode: libc::S_IFREG }),
 306             libc::DT_SOCK => Ok(FileType { mode: libc::S_IFSOCK }),
 307             libc::DT_DIR => Ok(FileType { mode: libc::S_IFDIR }),
 308             libc::DT_BLK => Ok(FileType { mode: libc::S_IFBLK }),
 309             _ => lstat(&self.path()).map(|m| m.file_type()),
 310         }
 311     }
 312
 313     #[cfg(any(target_os = "macos",
 314               target_os = "ios",
 315               target_os = "linux",
 316               target_os = "emscripten",
 317               target_os = "android",
 318               target_os = "solaris"))]
 319     pub fn ino(&self) -> u64 {
 320         self.entry.d_ino as u64
 321     }
 322
 323     #[cfg(any(target_os = "freebsd",
 324               target_os = "openbsd",
 325               target_os = "bitrig",
 326               target_os = "netbsd",
 327               target_os = "dragonfly"))]
 328     pub fn ino(&self) -> u64 {
 329         self.entry.d_fileno as u64
 330     }
 331
 332     #[cfg(any(target_os = "macos",
 333               target_os = "ios",
 334               target_os = "netbsd",
 335               target_os = "openbsd",
 336               target_os = "freebsd",
 337               target_os = "dragonfly",
 338               target_os = "bitrig"))]
 339     fn name_bytes(&self) -> &[u8] {
 340         unsafe {
 341             ::slice::from_raw_parts(self.entry.d_name.as_ptr() as *const u8,
 342                                     self.entry.d_namlen as usize)
 343         }
 344     }
 345     #[cfg(any(target_os = "android",
 346               target_os = "linux",
 347               target_os = "emscripten"))]
 348     fn name_bytes(&self) -> &[u8] {
 349         unsafe {
 350             CStr::from_ptr(self.entry.d_name.as_ptr()).to_bytes()
 351         }
 352     }
 353     #[cfg(target_os = "solaris")]
 354     fn name_bytes(&self) -> &[u8] {
 355         &*self.name
 356     }
 357 }
 358
 359 impl OpenOptions {
 360     pub fn new() -> OpenOptions {
 361         OpenOptions {
 362             // generic
 363             read: false,
 364             write: false,
 365             append: false,
 366             truncate: false,
 367             create: false,
 368             create_new: false,
 369             // system-specific
 370             custom_flags: 0,
 371             mode: 0o666,
 372         }
 373     }
 374
 375     pub fn read(&mut self, read: bool) { self.read = read; }
 376     pub fn write(&mut self, write: bool) { self.write = write; }
 377     pub fn append(&mut self, append: bool) { self.append = append; }
 378     pub fn truncate(&mut self, truncate: bool) { self.truncate = truncate; }
 379     pub fn create(&mut self, create: bool) { self.create = create; }
 380     pub fn create_new(&mut self, create_new: bool) { self.create_new = create_new; }
 381
 382     pub fn custom_flags(&mut self, flags: i32) { self.custom_flags = flags; }
 383     pub fn mode(&mut self, mode: u32) { self.mode = mode as mode_t; }
 384
 385     fn get_access_mode(&self) -> io::Result<c_int> {
 386         match (self.read, self.write, self.append) {
 387             (true,  false, false) => Ok(libc::O_RDONLY),
 388             (false, true,  false) => Ok(libc::O_WRONLY),
 389             (true,  true,  false) => Ok(libc::O_RDWR),
 390             (false, _,     true)  => Ok(libc::O_WRONLY | libc::O_APPEND),
 391             (true,  _,     true)  => Ok(libc::O_RDWR | libc::O_APPEND),
 392             (false, false, false) => Err(Error::from_raw_os_error(libc::EINVAL)),
 393         }
 394     }
 395
 396     fn get_creation_mode(&self) -> io::Result<c_int> {
 397         match (self.write, self.append) {
 398             (true, false) => {}
 399             (false, false) =>
 400                 if self.truncate || self.create || self.create_new {
 401                     return Err(Error::from_raw_os_error(libc::EINVAL));
 402                 },
 403             (_, true) =>
 404                 if self.truncate && !self.create_new {
 405                     return Err(Error::from_raw_os_error(libc::EINVAL));
 406                 },
 407         }
 408
 409         Ok(match (self.create, self.truncate, self.create_new) {
 410                 (false, false, false) => 0,
 411                 (true,  false, false) => libc::O_CREAT,
 412                 (false, true,  false) => libc::O_TRUNC,
 413                 (true,  true,  false) => libc::O_CREAT | libc::O_TRUNC,
 414                 (_,      _,    true)  => libc::O_CREAT | libc::O_EXCL,
 415            })
 416     }
 417 }
 418
 419 impl File {
 420     pub fn open(path: &Path, opts: &OpenOptions) -> io::Result<File> {
 421         let path = cstr(path)?;
 422         File::open_c(&path, opts)
 423     }
 424
 425     pub fn open_c(path: &CStr, opts: &OpenOptions) -> io::Result<File> {
 426         let flags = libc::O_CLOEXEC |
 427                     opts.get_access_mode()? |
 428                     opts.get_creation_mode()? |
 429                     (opts.custom_flags as c_int & !libc::O_ACCMODE);
 430         let fd = cvt_r(|| unsafe {
 431             open64(path.as_ptr(), flags, opts.mode as c_int)
 432         })?;
 433         let fd = FileDesc::new(fd);
 434
 435         // Currently the standard library supports Linux 2.6.18 which did not
 436         // have the O_CLOEXEC flag (passed above). If we're running on an older
 437         // Linux kernel then the flag is just ignored by the OS, so we continue
 438         // to explicitly ask for a CLOEXEC fd here.
 439         //
 440         // The CLOEXEC flag, however, is supported on versions of OSX/BSD/etc
 441         // that we support, so we only do this on Linux currently.
 442         if cfg!(target_os = "linux") {
 443             fd.set_cloexec();
 444         }
 445
 446         Ok(File(fd))
 447     }
 448
 449     pub fn file_attr(&self) -> io::Result<FileAttr> {
 450         let mut stat: stat64 = unsafe { mem::zeroed() };
 451         cvt(unsafe {
 452             fstat64(self.0.raw(), &mut stat)
 453         })?;
 454         Ok(FileAttr { stat: stat })
 455     }
 456
 457     pub fn fsync(&self) -> io::Result<()> {
 458         cvt_r(|| unsafe { libc::fsync(self.0.raw()) })?;
 459         Ok(())
 460     }
 461
 462     pub fn datasync(&self) -> io::Result<()> {
 463         cvt_r(|| unsafe { os_datasync(self.0.raw()) })?;
 464         return Ok(());
 465
 466         #[cfg(any(target_os = "macos", target_os = "ios"))]
 467         unsafe fn os_datasync(fd: c_int) -> c_int {
 468             libc::fcntl(fd, libc::F_FULLFSYNC)
 469         }
 470         #[cfg(target_os = "linux")]
 471         unsafe fn os_datasync(fd: c_int) -> c_int { libc::fdatasync(fd) }
 472         #[cfg(not(any(target_os = "macos",
 473                       target_os = "ios",
 474                       target_os = "linux")))]
 475         unsafe fn os_datasync(fd: c_int) -> c_int { libc::fsync(fd) }
 476     }
 477
 478     pub fn truncate(&self, size: u64) -> io::Result<()> {
 479         cvt_r(|| unsafe {
 480             ftruncate64(self.0.raw(), size as off64_t)
 481         })?;
 482         Ok(())
 483     }
 484
 485     pub fn read(&self, buf: &mut [u8]) -> io::Result<usize> {
 486         self.0.read(buf)
 487     }
 488
 489     pub fn read_to_end(&self, buf: &mut Vec<u8>) -> io::Result<usize> {
 490         self.0.read_to_end(buf)
 491     }
 492
 493     pub fn write(&self, buf: &[u8]) -> io::Result<usize> {
 494         self.0.write(buf)
 495     }
 496
 497     pub fn flush(&self) -> io::Result<()> { Ok(()) }
 498
 499     pub fn seek(&self, pos: SeekFrom) -> io::Result<u64> {
 500         let (whence, pos) = match pos {
 501             SeekFrom::Start(off) => (libc::SEEK_SET, off as off64_t),
 502             SeekFrom::End(off) => (libc::SEEK_END, off as off64_t),
 503             SeekFrom::Current(off) => (libc::SEEK_CUR, off as off64_t),
 504         };
 505         let n = cvt(unsafe { lseek64(self.0.raw(), pos, whence) })?;
 506         Ok(n as u64)
 507     }
 508
 509     pub fn duplicate(&self) -> io::Result<File> {
 510         self.0.duplicate().map(File)
 511     }
 512
 513     pub fn fd(&self) -> &FileDesc { &self.0 }
 514
 515     pub fn into_fd(self) -> FileDesc { self.0 }
 516 }
 517
 518 impl DirBuilder {
 519     pub fn new() -> DirBuilder {
 520         DirBuilder { mode: 0o777 }
 521     }
 522
 523     pub fn mkdir(&self, p: &Path) -> io::Result<()> {
 524         let p = cstr(p)?;
 525         cvt(unsafe { libc::mkdir(p.as_ptr(), self.mode) })?;
 526         Ok(())
 527     }
 528
 529     pub fn set_mode(&mut self, mode: u32) {
 530         self.mode = mode as mode_t;
 531     }
 532 }
 533
 534 fn cstr(path: &Path) -> io::Result<CString> {
 535     Ok(CString::new(path.as_os_str().as_bytes())?)
 536 }
 537
 538 impl FromInner<c_int> for File {
 539     fn from_inner(fd: c_int) -> File {
 540         File(FileDesc::new(fd))
 541     }
 542 }
 543
 544 impl fmt::Debug for File {
 545     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 546         #[cfg(target_os = "linux")]
 547         fn get_path(fd: c_int) -> Option<PathBuf> {
 548             use string::ToString;
 549             let mut p = PathBuf::from("/proc/self/fd");
 550             p.push(&fd.to_string());
 551             readlink(&p).ok()
 552         }
 553
 554         #[cfg(target_os = "macos")]
 555         fn get_path(fd: c_int) -> Option<PathBuf> {
 556             // FIXME: The use of PATH_MAX is generally not encouraged, but it
 557             // is inevitable in this case because OS X defines `fcntl` with
 558             // `F_GETPATH` in terms of `MAXPATHLEN`, and there are no
 559             // alternatives. If a better method is invented, it should be used
 560             // instead.
 561             let mut buf = vec![0;libc::PATH_MAX as usize];
 562             let n = unsafe { libc::fcntl(fd, libc::F_GETPATH, buf.as_ptr()) };
 563             if n == -1 {
 564                 return None;
 565             }
 566             let l = buf.iter().position(|&c| c == 0).unwrap();
 567             buf.truncate(l as usize);
 568             buf.shrink_to_fit();
 569             Some(PathBuf::from(OsString::from_vec(buf)))
 570         }
 571
 572         #[cfg(not(any(target_os = "linux", target_os = "macos")))]
 573         fn get_path(_fd: c_int) -> Option<PathBuf> {
 574             // FIXME(#24570): implement this for other Unix platforms
 575             None
 576         }
 577
 578         #[cfg(any(target_os = "linux", target_os = "macos"))]
 579         fn get_mode(fd: c_int) -> Option<(bool, bool)> {
 580             let mode = unsafe { libc::fcntl(fd, libc::F_GETFL) };
 581             if mode == -1 {
 582                 return None;
 583             }
 584             match mode & libc::O_ACCMODE {
 585                 libc::O_RDONLY => Some((true, false)),
 586                 libc::O_RDWR => Some((true, true)),
 587                 libc::O_WRONLY => Some((false, true)),
 588                 _ => None
 589             }
 590         }
 591
 592         #[cfg(not(any(target_os = "linux", target_os = "macos")))]
 593         fn get_mode(_fd: c_int) -> Option<(bool, bool)> {
 594             // FIXME(#24570): implement this for other Unix platforms
 595             None
 596         }
 597
 598         let fd = self.0.raw();
 599         let mut b = f.debug_struct("File");
 600         b.field("fd", &fd);
 601         if let Some(path) = get_path(fd) {
 602             b.field("path", &path);
 603         }
 604         if let Some((read, write)) = get_mode(fd) {
 605             b.field("read", &read).field("write", &write);
 606         }
 607         b.finish()
 608     }
 609 }
 610
 611 pub fn readdir(p: &Path) -> io::Result<ReadDir> {
 612     let root = Arc::new(p.to_path_buf());
 613     let p = cstr(p)?;
 614     unsafe {
 615         let ptr = libc::opendir(p.as_ptr());
 616         if ptr.is_null() {
 617             Err(Error::last_os_error())
 618         } else {
 619             Ok(ReadDir { dirp: Dir(ptr), root: root })
 620         }
 621     }
 622 }
 623
 624 pub fn unlink(p: &Path) -> io::Result<()> {
 625     let p = cstr(p)?;
 626     cvt(unsafe { libc::unlink(p.as_ptr()) })?;
 627     Ok(())
 628 }
 629
 630 pub fn rename(old: &Path, new: &Path) -> io::Result<()> {
 631     let old = cstr(old)?;
 632     let new = cstr(new)?;
 633     cvt(unsafe { libc::rename(old.as_ptr(), new.as_ptr()) })?;
 634     Ok(())
 635 }
 636
 637 pub fn set_perm(p: &Path, perm: FilePermissions) -> io::Result<()> {
 638     let p = cstr(p)?;
 639     cvt_r(|| unsafe { libc::chmod(p.as_ptr(), perm.mode) })?;
 640     Ok(())
 641 }
 642
 643 pub fn rmdir(p: &Path) -> io::Result<()> {
 644     let p = cstr(p)?;
 645     cvt(unsafe { libc::rmdir(p.as_ptr()) })?;
 646     Ok(())
 647 }
 648
 649 pub fn remove_dir_all(path: &Path) -> io::Result<()> {
 650     let filetype = lstat(path)?.file_type();
 651     if filetype.is_symlink() {
 652         unlink(path)
 653     } else {
 654         remove_dir_all_recursive(path)
 655     }
 656 }
 657
 658 fn remove_dir_all_recursive(path: &Path) -> io::Result<()> {
 659     for child in readdir(path)? {
 660         let child = child?;
 661         if child.file_type()?.is_dir() {
 662             remove_dir_all_recursive(&child.path())?;
 663         } else {
 664             unlink(&child.path())?;
 665         }
 666     }
 667     rmdir(path)
 668 }
 669
 670 pub fn readlink(p: &Path) -> io::Result<PathBuf> {
 671     let c_path = cstr(p)?;
 672     let p = c_path.as_ptr();
 673
 674     let mut buf = Vec::with_capacity(256);
 675
 676     loop {
 677         let buf_read = cvt(unsafe {
 678             libc::readlink(p, buf.as_mut_ptr() as *mut _, buf.capacity() as libc::size_t)
 679         })? as usize;
 680
 681         unsafe { buf.set_len(buf_read); }
 682
 683         if buf_read != buf.capacity() {
 684             buf.shrink_to_fit();
 685
 686             return Ok(PathBuf::from(OsString::from_vec(buf)));
 687         }
 688
 689         // Trigger the internal buffer resizing logic of `Vec` by requiring
 690         // more space than the current capacity. The length is guaranteed to be
 691         // the same as the capacity due to the if statement above.
 692         buf.reserve(1);
 693     }
 694 }
 695
 696 pub fn symlink(src: &Path, dst: &Path) -> io::Result<()> {
 697     let src = cstr(src)?;
 698     let dst = cstr(dst)?;
 699     cvt(unsafe { libc::symlink(src.as_ptr(), dst.as_ptr()) })?;
 700     Ok(())
 701 }
 702
 703 pub fn link(src: &Path, dst: &Path) -> io::Result<()> {
 704     let src = cstr(src)?;
 705     let dst = cstr(dst)?;
 706     cvt(unsafe { libc::link(src.as_ptr(), dst.as_ptr()) })?;
 707     Ok(())
 708 }
 709
 710 pub fn stat(p: &Path) -> io::Result<FileAttr> {
 711     let p = cstr(p)?;
 712     let mut stat: stat64 = unsafe { mem::zeroed() };
 713     cvt(unsafe {
 714         stat64(p.as_ptr(), &mut stat as *mut _ as *mut _)
 715     })?;
 716     Ok(FileAttr { stat: stat })
 717 }
 718
 719 pub fn lstat(p: &Path) -> io::Result<FileAttr> {
 720     let p = cstr(p)?;
 721     let mut stat: stat64 = unsafe { mem::zeroed() };
 722     cvt(unsafe {
 723         lstat64(p.as_ptr(), &mut stat as *mut _ as *mut _)
 724     })?;
 725     Ok(FileAttr { stat: stat })
 726 }
 727
 728 pub fn canonicalize(p: &Path) -> io::Result<PathBuf> {
 729     let path = CString::new(p.as_os_str().as_bytes())?;
 730     let buf;
 731     unsafe {
 732         let r = libc::realpath(path.as_ptr(), ptr::null_mut());
 733         if r.is_null() {
 734             return Err(io::Error::last_os_error())
 735         }
 736         buf = CStr::from_ptr(r).to_bytes().to_vec();
 737         libc::free(r as *mut _);
 738     }
 739     Ok(PathBuf::from(OsString::from_vec(buf)))
 740 }
 741
 742 pub fn copy(from: &Path, to: &Path) -> io::Result<u64> {
 743     use fs::{File, set_permissions};
 744     if !from.is_file() {
 745         return Err(Error::new(ErrorKind::InvalidInput,
 746                               "the source path is not an existing regular file"))
 747     }
 748
 749     let mut reader = File::open(from)?;
 750     let mut writer = File::create(to)?;
 751     let perm = reader.metadata()?.permissions();
 752
 753     let ret = io::copy(&mut reader, &mut writer)?;
 754     set_permissions(to, perm)?;
 755     Ok(ret)
 756 }