src/libstd/sys/unix/os.rs

   1 // Copyright 2015 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 //! Implementation of `std::os` functionality for unix systems
  12
  13 #![allow(unused_imports)] // lots of cfg code here
  14
  15 use os::unix::prelude::*;
  16
  17 use error::Error as StdError;
  18 use ffi::{CString, CStr, OsString, OsStr};
  19 use fmt;
  20 use io;
  21 use iter;
  22 use libc::{self, c_int, c_char, c_void};
  23 use marker::PhantomData;
  24 use mem;
  25 use memchr;
  26 use path::{self, PathBuf};
  27 use ptr;
  28 use slice;
  29 use str;
  30 use sys_common::mutex::Mutex;
  31 use sys::cvt;
  32 use sys::fd;
  33 use vec;
  34
  35 const TMPBUF_SZ: usize = 128;
  36 static ENV_LOCK: Mutex = Mutex::new();
  37
  38
  39 extern {
  40     #[cfg(not(target_os = "dragonfly"))]
  41     #[cfg_attr(any(target_os = "linux", target_os = "emscripten", target_os = "fuchsia"),
  42                link_name = "__errno_location")]
  43     #[cfg_attr(any(target_os = "bitrig",
  44                    target_os = "netbsd",
  45                    target_os = "openbsd",
  46                    target_os = "android",
  47                    target_env = "newlib"),
  48                link_name = "__errno")]
  49     #[cfg_attr(target_os = "solaris", link_name = "___errno")]
  50     #[cfg_attr(any(target_os = "macos",
  51                    target_os = "ios",
  52                    target_os = "freebsd"),
  53                link_name = "__error")]
  54     #[cfg_attr(target_os = "haiku", link_name = "_errnop")]
  55     fn errno_location() -> *mut c_int;
  56 }
  57
  58 /// Returns the platform-specific value of errno
  59 #[cfg(not(target_os = "dragonfly"))]
  60 pub fn errno() -> i32 {
  61     unsafe {
  62         (*errno_location()) as i32
  63     }
  64 }
  65
  66 /// Sets the platform-specific value of errno
  67 #[cfg(target_os = "solaris")] // only needed for readdir so far
  68 pub fn set_errno(e: i32) {
  69     unsafe {
  70         *errno_location() = e as c_int
  71     }
  72 }
  73
  74 #[cfg(target_os = "dragonfly")]
  75 pub fn errno() -> i32 {
  76     extern {
  77         #[thread_local]
  78         static errno: c_int;
  79     }
  80
  81     errno as i32
  82 }
  83
  84 /// Gets a detailed string description for the given error number.
  85 pub fn error_string(errno: i32) -> String {
  86     extern {
  87         #[cfg_attr(any(target_os = "linux", target_env = "newlib"),
  88                    link_name = "__xpg_strerror_r")]
  89         fn strerror_r(errnum: c_int, buf: *mut c_char,
  90                       buflen: libc::size_t) -> c_int;
  91     }
  92
  93     let mut buf = [0 as c_char; TMPBUF_SZ];
  94
  95     let p = buf.as_mut_ptr();
  96     unsafe {
  97         if strerror_r(errno as c_int, p, buf.len()) < 0 {
  98             panic!("strerror_r failure");
  99         }
 100
 101         let p = p as *const _;
 102         str::from_utf8(CStr::from_ptr(p).to_bytes()).unwrap().to_owned()
 103     }
 104 }
 105
 106 pub fn getcwd() -> io::Result<PathBuf> {
 107     let mut buf = Vec::with_capacity(512);
 108     loop {
 109         unsafe {
 110             let ptr = buf.as_mut_ptr() as *mut libc::c_char;
 111             if !libc::getcwd(ptr, buf.capacity()).is_null() {
 112                 let len = CStr::from_ptr(buf.as_ptr() as *const libc::c_char).to_bytes().len();
 113                 buf.set_len(len);
 114                 buf.shrink_to_fit();
 115                 return Ok(PathBuf::from(OsString::from_vec(buf)));
 116             } else {
 117                 let error = io::Error::last_os_error();
 118                 if error.raw_os_error() != Some(libc::ERANGE) {
 119                     return Err(error);
 120                 }
 121             }
 122
 123             // Trigger the internal buffer resizing logic of `Vec` by requiring
 124             // more space than the current capacity.
 125             let cap = buf.capacity();
 126             buf.set_len(cap);
 127             buf.reserve(1);
 128         }
 129     }
 130 }
 131
 132 pub fn chdir(p: &path::Path) -> io::Result<()> {
 133     let p: &OsStr = p.as_ref();
 134     let p = CString::new(p.as_bytes())?;
 135     unsafe {
 136         match libc::chdir(p.as_ptr()) == (0 as c_int) {
 137             true => Ok(()),
 138             false => Err(io::Error::last_os_error()),
 139         }
 140     }
 141 }
 142
 143 pub struct SplitPaths<'a> {
 144     iter: iter::Map<slice::Split<'a, u8, fn(&u8) -> bool>,
 145                     fn(&'a [u8]) -> PathBuf>,
 146 }
 147
 148 pub fn split_paths(unparsed: &OsStr) -> SplitPaths {
 149     fn bytes_to_path(b: &[u8]) -> PathBuf {
 150         PathBuf::from(<OsStr as OsStrExt>::from_bytes(b))
 151     }
 152     fn is_colon(b: &u8) -> bool { *b == b':' }
 153     let unparsed = unparsed.as_bytes();
 154     SplitPaths {
 155         iter: unparsed.split(is_colon as fn(&u8) -> bool)
 156                       .map(bytes_to_path as fn(&[u8]) -> PathBuf)
 157     }
 158 }
 159
 160 impl<'a> Iterator for SplitPaths<'a> {
 161     type Item = PathBuf;
 162     fn next(&mut self) -> Option<PathBuf> { self.iter.next() }
 163     fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() }
 164 }
 165
 166 #[derive(Debug)]
 167 pub struct JoinPathsError;
 168
 169 pub fn join_paths<I, T>(paths: I) -> Result<OsString, JoinPathsError>
 170     where I: Iterator<Item=T>, T: AsRef<OsStr>
 171 {
 172     let mut joined = Vec::new();
 173     let sep = b':';
 174
 175     for (i, path) in paths.enumerate() {
 176         let path = path.as_ref().as_bytes();
 177         if i > 0 { joined.push(sep) }
 178         if path.contains(&sep) {
 179             return Err(JoinPathsError)
 180         }
 181         joined.extend_from_slice(path);
 182     }
 183     Ok(OsStringExt::from_vec(joined))
 184 }
 185
 186 impl fmt::Display for JoinPathsError {
 187     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 188         "path segment contains separator `:`".fmt(f)
 189     }
 190 }
 191
 192 impl StdError for JoinPathsError {
 193     fn description(&self) -> &str { "failed to join paths" }
 194 }
 195
 196 #[cfg(target_os = "freebsd")]
 197 pub fn current_exe() -> io::Result<PathBuf> {
 198     unsafe {
 199         let mut mib = [libc::CTL_KERN as c_int,
 200                        libc::KERN_PROC as c_int,
 201                        libc::KERN_PROC_PATHNAME as c_int,
 202                        -1 as c_int];
 203         let mut sz = 0;
 204         cvt(libc::sysctl(mib.as_mut_ptr(), mib.len() as ::libc::c_uint,
 205                          ptr::null_mut(), &mut sz, ptr::null_mut(), 0))?;
 206         if sz == 0 {
 207             return Err(io::Error::last_os_error())
 208         }
 209         let mut v: Vec<u8> = Vec::with_capacity(sz);
 210         cvt(libc::sysctl(mib.as_mut_ptr(), mib.len() as ::libc::c_uint,
 211                          v.as_mut_ptr() as *mut libc::c_void, &mut sz,
 212                          ptr::null_mut(), 0))?;
 213         if sz == 0 {
 214             return Err(io::Error::last_os_error());
 215         }
 216         v.set_len(sz - 1); // chop off trailing NUL
 217         Ok(PathBuf::from(OsString::from_vec(v)))
 218     }
 219 }
 220
 221 #[cfg(target_os = "dragonfly")]
 222 pub fn current_exe() -> io::Result<PathBuf> {
 223     ::fs::read_link("/proc/curproc/file")
 224 }
 225
 226 #[cfg(target_os = "netbsd")]
 227 pub fn current_exe() -> io::Result<PathBuf> {
 228     ::fs::read_link("/proc/curproc/exe")
 229 }
 230
 231 #[cfg(any(target_os = "bitrig", target_os = "openbsd"))]
 232 pub fn current_exe() -> io::Result<PathBuf> {
 233     unsafe {
 234         let mut mib = [libc::CTL_KERN,
 235                        libc::KERN_PROC_ARGS,
 236                        libc::getpid(),
 237                        libc::KERN_PROC_ARGV];
 238         let mib = mib.as_mut_ptr();
 239         let mut argv_len = 0;
 240         cvt(libc::sysctl(mib, 4, ptr::null_mut(), &mut argv_len,
 241                          ptr::null_mut(), 0))?;
 242         let mut argv = Vec::<*const libc::c_char>::with_capacity(argv_len as usize);
 243         cvt(libc::sysctl(mib, 4, argv.as_mut_ptr() as *mut _,
 244                          &mut argv_len, ptr::null_mut(), 0))?;
 245         argv.set_len(argv_len as usize);
 246         if argv[0].is_null() {
 247             return Err(io::Error::new(io::ErrorKind::Other,
 248                                       "no current exe available"))
 249         }
 250         let argv0 = CStr::from_ptr(argv[0]).to_bytes();
 251         if argv0[0] == b'.' || argv0.iter().any(|b| *b == b'/') {
 252             ::fs::canonicalize(OsStr::from_bytes(argv0))
 253         } else {
 254             Ok(PathBuf::from(OsStr::from_bytes(argv0)))
 255         }
 256     }
 257 }
 258
 259 #[cfg(any(target_os = "linux", target_os = "android", target_os = "emscripten"))]
 260 pub fn current_exe() -> io::Result<PathBuf> {
 261     ::fs::read_link("/proc/self/exe")
 262 }
 263
 264 #[cfg(any(target_os = "macos", target_os = "ios"))]
 265 pub fn current_exe() -> io::Result<PathBuf> {
 266     extern {
 267         fn _NSGetExecutablePath(buf: *mut libc::c_char,
 268                                 bufsize: *mut u32) -> libc::c_int;
 269     }
 270     unsafe {
 271         let mut sz: u32 = 0;
 272         _NSGetExecutablePath(ptr::null_mut(), &mut sz);
 273         if sz == 0 { return Err(io::Error::last_os_error()); }
 274         let mut v: Vec<u8> = Vec::with_capacity(sz as usize);
 275         let err = _NSGetExecutablePath(v.as_mut_ptr() as *mut i8, &mut sz);
 276         if err != 0 { return Err(io::Error::last_os_error()); }
 277         v.set_len(sz as usize - 1); // chop off trailing NUL
 278         Ok(PathBuf::from(OsString::from_vec(v)))
 279     }
 280 }
 281
 282 #[cfg(any(target_os = "solaris"))]
 283 pub fn current_exe() -> io::Result<PathBuf> {
 284     extern {
 285         fn getexecname() -> *const c_char;
 286     }
 287     unsafe {
 288         let path = getexecname();
 289         if path.is_null() {
 290             Err(io::Error::last_os_error())
 291         } else {
 292             let filename = CStr::from_ptr(path).to_bytes();
 293             let path = PathBuf::from(<OsStr as OsStrExt>::from_bytes(filename));
 294
 295             // Prepend a current working directory to the path if
 296             // it doesn't contain an absolute pathname.
 297             if filename[0] == b'/' {
 298                 Ok(path)
 299             } else {
 300                 getcwd().map(|cwd| cwd.join(path))
 301             }
 302         }
 303     }
 304 }
 305
 306 #[cfg(target_os = "haiku")]
 307 pub fn current_exe() -> io::Result<PathBuf> {
 308     // Use Haiku's image info functions
 309     #[repr(C)]
 310     struct image_info {
 311         id: i32,
 312         type_: i32,
 313         sequence: i32,
 314         init_order: i32,
 315         init_routine: *mut libc::c_void,    // function pointer
 316         term_routine: *mut libc::c_void,    // function pointer
 317         device: libc::dev_t,
 318         node: libc::ino_t,
 319         name: [libc::c_char; 1024],         // MAXPATHLEN
 320         text: *mut libc::c_void,
 321         data: *mut libc::c_void,
 322         text_size: i32,
 323         data_size: i32,
 324         api_version: i32,
 325         abi: i32,
 326     }
 327
 328     unsafe {
 329         extern {
 330             fn _get_next_image_info(team_id: i32, cookie: *mut i32,
 331                 info: *mut image_info, size: i32) -> i32;
 332         }
 333
 334         let mut info: image_info = mem::zeroed();
 335         let mut cookie: i32 = 0;
 336         // the executable can be found at team id 0
 337         let result = _get_next_image_info(0, &mut cookie, &mut info,
 338             mem::size_of::<image_info>() as i32);
 339         if result != 0 {
 340             use io::ErrorKind;
 341             Err(io::Error::new(ErrorKind::Other, "Error getting executable path"))
 342         } else {
 343             let name = CStr::from_ptr(info.name.as_ptr()).to_bytes();
 344             Ok(PathBuf::from(OsStr::from_bytes(name)))
 345         }
 346     }
 347 }
 348
 349 #[cfg(target_os = "fuchsia")]
 350 pub fn current_exe() -> io::Result<PathBuf> {
 351     use io::ErrorKind;
 352     Err(io::Error::new(ErrorKind::Other, "Not yet implemented on fuchsia"))
 353 }
 354
 355 pub struct Env {
 356     iter: vec::IntoIter<(OsString, OsString)>,
 357     _dont_send_or_sync_me: PhantomData<*mut ()>,
 358 }
 359
 360 impl Iterator for Env {
 361     type Item = (OsString, OsString);
 362     fn next(&mut self) -> Option<(OsString, OsString)> { self.iter.next() }
 363     fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() }
 364 }
 365
 366 #[cfg(target_os = "macos")]
 367 pub unsafe fn environ() -> *mut *const *const c_char {
 368     extern { fn _NSGetEnviron() -> *mut *const *const c_char; }
 369     _NSGetEnviron()
 370 }
 371
 372 #[cfg(not(target_os = "macos"))]
 373 pub unsafe fn environ() -> *mut *const *const c_char {
 374     extern { static mut environ: *const *const c_char; }
 375     &mut environ
 376 }
 377
 378 /// Returns a vector of (variable, value) byte-vector pairs for all the
 379 /// environment variables of the current process.
 380 pub fn env() -> Env {
 381     unsafe {
 382         ENV_LOCK.lock();
 383         let mut environ = *environ();
 384         if environ == ptr::null() {
 385             ENV_LOCK.unlock();
 386             panic!("os::env() failure getting env string from OS: {}",
 387                    io::Error::last_os_error());
 388         }
 389         let mut result = Vec::new();
 390         while *environ != ptr::null() {
 391             if let Some(key_value) = parse(CStr::from_ptr(*environ).to_bytes()) {
 392                 result.push(key_value);
 393             }
 394             environ = environ.offset(1);
 395         }
 396         let ret = Env {
 397             iter: result.into_iter(),
 398             _dont_send_or_sync_me: PhantomData,
 399         };
 400         ENV_LOCK.unlock();
 401         return ret
 402     }
 403
 404     fn parse(input: &[u8]) -> Option<(OsString, OsString)> {
 405         // Strategy (copied from glibc): Variable name and value are separated
 406         // by an ASCII equals sign '='. Since a variable name must not be
 407         // empty, allow variable names starting with an equals sign. Skip all
 408         // malformed lines.
 409         if input.is_empty() {
 410             return None;
 411         }
 412         let pos = memchr::memchr(b'=', &input[1..]).map(|p| p + 1);
 413         pos.map(|p| (
 414             OsStringExt::from_vec(input[..p].to_vec()),
 415             OsStringExt::from_vec(input[p+1..].to_vec()),
 416         ))
 417     }
 418 }
 419
 420 pub fn getenv(k: &OsStr) -> io::Result<Option<OsString>> {
 421     // environment variables with a nul byte can't be set, so their value is
 422     // always None as well
 423     let k = CString::new(k.as_bytes())?;
 424     unsafe {
 425         ENV_LOCK.lock();
 426         let s = libc::getenv(k.as_ptr()) as *const _;
 427         let ret = if s.is_null() {
 428             None
 429         } else {
 430             Some(OsStringExt::from_vec(CStr::from_ptr(s).to_bytes().to_vec()))
 431         };
 432         ENV_LOCK.unlock();
 433         return Ok(ret)
 434     }
 435 }
 436
 437 pub fn setenv(k: &OsStr, v: &OsStr) -> io::Result<()> {
 438     let k = CString::new(k.as_bytes())?;
 439     let v = CString::new(v.as_bytes())?;
 440
 441     unsafe {
 442         ENV_LOCK.lock();
 443         let ret = cvt(libc::setenv(k.as_ptr(), v.as_ptr(), 1)).map(|_| ());
 444         ENV_LOCK.unlock();
 445         return ret
 446     }
 447 }
 448
 449 pub fn unsetenv(n: &OsStr) -> io::Result<()> {
 450     let nbuf = CString::new(n.as_bytes())?;
 451
 452     unsafe {
 453         ENV_LOCK.lock();
 454         let ret = cvt(libc::unsetenv(nbuf.as_ptr())).map(|_| ());
 455         ENV_LOCK.unlock();
 456         return ret
 457     }
 458 }
 459
 460 pub fn page_size() -> usize {
 461     unsafe {
 462         libc::sysconf(libc::_SC_PAGESIZE) as usize
 463     }
 464 }
 465
 466 pub fn temp_dir() -> PathBuf {
 467     ::env::var_os("TMPDIR").map(PathBuf::from).unwrap_or_else(|| {
 468         if cfg!(target_os = "android") {
 469             PathBuf::from("/data/local/tmp")
 470         } else {
 471             PathBuf::from("/tmp")
 472         }
 473     })
 474 }
 475
 476 pub fn home_dir() -> Option<PathBuf> {
 477     return ::env::var_os("HOME").or_else(|| unsafe {
 478         fallback()
 479     }).map(PathBuf::from);
 480
 481     #[cfg(any(target_os = "android",
 482               target_os = "ios",
 483               target_os = "nacl",
 484               target_os = "emscripten"))]
 485     unsafe fn fallback() -> Option<OsString> { None }
 486     #[cfg(not(any(target_os = "android",
 487                   target_os = "ios",
 488                   target_os = "nacl",
 489                   target_os = "emscripten")))]
 490     unsafe fn fallback() -> Option<OsString> {
 491         #[cfg(not(target_os = "solaris"))]
 492         unsafe fn getpwduid_r(me: libc::uid_t, passwd: &mut libc::passwd,
 493                               buf: &mut Vec<c_char>) -> Option<()> {
 494             let mut result = ptr::null_mut();
 495             match libc::getpwuid_r(me, passwd, buf.as_mut_ptr(),
 496                                    buf.capacity(),
 497                                    &mut result) {
 498                 0 if !result.is_null() => Some(()),
 499                 _ => None
 500             }
 501         }
 502
 503         #[cfg(target_os = "solaris")]
 504         unsafe fn getpwduid_r(me: libc::uid_t, passwd: &mut libc::passwd,
 505                               buf: &mut Vec<c_char>) -> Option<()> {
 506             // getpwuid_r semantics is different on Illumos/Solaris:
 507             // http://illumos.org/man/3c/getpwuid_r
 508             let result = libc::getpwuid_r(me, passwd, buf.as_mut_ptr(),
 509                                           buf.capacity());
 510             if result.is_null() { None } else { Some(()) }
 511         }
 512
 513         let amt = match libc::sysconf(libc::_SC_GETPW_R_SIZE_MAX) {
 514             n if n < 0 => 512 as usize,
 515             n => n as usize,
 516         };
 517         let mut buf = Vec::with_capacity(amt);
 518         let mut passwd: libc::passwd = mem::zeroed();
 519
 520         if getpwduid_r(libc::getuid(), &mut passwd, &mut buf).is_some() {
 521             let ptr = passwd.pw_dir as *const _;
 522             let bytes = CStr::from_ptr(ptr).to_bytes().to_vec();
 523             Some(OsStringExt::from_vec(bytes))
 524         } else {
 525             None
 526         }
 527     }
 528 }
 529
 530 pub fn exit(code: i32) -> ! {
 531     unsafe { libc::exit(code as c_int) }
 532 }