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 prelude::v1::*;
  16 use os::unix::prelude::*;
  17
  18 use error::Error as StdError;
  19 use ffi::{CString, CStr, OsString, OsStr};
  20 use fmt;
  21 use io;
  22 use iter;
  23 use libc::{self, c_int, c_char, c_void};
  24 use mem;
  25 use memchr;
  26 use path::{self, PathBuf};
  27 use ptr;
  28 use slice;
  29 use str;
  30 use sync::StaticMutex;
  31 use sys::cvt;
  32 use sys::fd;
  33 use vec;
  34
  35 const TMPBUF_SZ: usize = 128;
  36 static ENV_LOCK: StaticMutex = StaticMutex::new();
  37
  38 /// Returns the platform-specific value of errno
  39 #[cfg(not(target_os = "dragonfly"))]
  40 pub fn errno() -> i32 {
  41     extern {
  42         #[cfg_attr(any(target_os = "linux", target_os = "emscripten"),
  43                    link_name = "__errno_location")]
  44         #[cfg_attr(any(target_os = "bitrig",
  45                        target_os = "netbsd",
  46                        target_os = "openbsd",
  47                        target_os = "android",
  48                        target_env = "newlib"),
  49                    link_name = "__errno")]
  50         #[cfg_attr(target_os = "solaris", link_name = "___errno")]
  51         #[cfg_attr(any(target_os = "macos",
  52                        target_os = "ios",
  53                        target_os = "freebsd"),
  54                    link_name = "__error")]
  55         fn errno_location() -> *const c_int;
  56     }
  57
  58     unsafe {
  59         (*errno_location()) as i32
  60     }
  61 }
  62
  63 #[cfg(target_os = "dragonfly")]
  64 pub fn errno() -> i32 {
  65     extern {
  66         #[thread_local]
  67         static errno: c_int;
  68     }
  69
  70     errno as i32
  71 }
  72
  73 /// Gets a detailed string description for the given error number.
  74 pub fn error_string(errno: i32) -> String {
  75     extern {
  76         #[cfg_attr(any(target_os = "linux", target_env = "newlib"),
  77                    link_name = "__xpg_strerror_r")]
  78         fn strerror_r(errnum: c_int, buf: *mut c_char,
  79                       buflen: libc::size_t) -> c_int;
  80     }
  81
  82     let mut buf = [0 as c_char; TMPBUF_SZ];
  83
  84     let p = buf.as_mut_ptr();
  85     unsafe {
  86         if strerror_r(errno as c_int, p, buf.len() as libc::size_t) < 0 {
  87             panic!("strerror_r failure");
  88         }
  89
  90         let p = p as *const _;
  91         str::from_utf8(CStr::from_ptr(p).to_bytes()).unwrap().to_owned()
  92     }
  93 }
  94
  95 pub fn getcwd() -> io::Result<PathBuf> {
  96     let mut buf = Vec::with_capacity(512);
  97     loop {
  98         unsafe {
  99             let ptr = buf.as_mut_ptr() as *mut libc::c_char;
 100             if !libc::getcwd(ptr, buf.capacity() as libc::size_t).is_null() {
 101                 let len = CStr::from_ptr(buf.as_ptr() as *const libc::c_char).to_bytes().len();
 102                 buf.set_len(len);
 103                 buf.shrink_to_fit();
 104                 return Ok(PathBuf::from(OsString::from_vec(buf)));
 105             } else {
 106                 let error = io::Error::last_os_error();
 107                 if error.raw_os_error() != Some(libc::ERANGE) {
 108                     return Err(error);
 109                 }
 110             }
 111
 112             // Trigger the internal buffer resizing logic of `Vec` by requiring
 113             // more space than the current capacity.
 114             let cap = buf.capacity();
 115             buf.set_len(cap);
 116             buf.reserve(1);
 117         }
 118     }
 119 }
 120
 121 pub fn chdir(p: &path::Path) -> io::Result<()> {
 122     let p: &OsStr = p.as_ref();
 123     let p = CString::new(p.as_bytes())?;
 124     unsafe {
 125         match libc::chdir(p.as_ptr()) == (0 as c_int) {
 126             true => Ok(()),
 127             false => Err(io::Error::last_os_error()),
 128         }
 129     }
 130 }
 131
 132 pub struct SplitPaths<'a> {
 133     iter: iter::Map<slice::Split<'a, u8, fn(&u8) -> bool>,
 134                     fn(&'a [u8]) -> PathBuf>,
 135 }
 136
 137 pub fn split_paths(unparsed: &OsStr) -> SplitPaths {
 138     fn bytes_to_path(b: &[u8]) -> PathBuf {
 139         PathBuf::from(<OsStr as OsStrExt>::from_bytes(b))
 140     }
 141     fn is_colon(b: &u8) -> bool { *b == b':' }
 142     let unparsed = unparsed.as_bytes();
 143     SplitPaths {
 144         iter: unparsed.split(is_colon as fn(&u8) -> bool)
 145                       .map(bytes_to_path as fn(&[u8]) -> PathBuf)
 146     }
 147 }
 148
 149 impl<'a> Iterator for SplitPaths<'a> {
 150     type Item = PathBuf;
 151     fn next(&mut self) -> Option<PathBuf> { self.iter.next() }
 152     fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() }
 153 }
 154
 155 #[derive(Debug)]
 156 pub struct JoinPathsError;
 157
 158 pub fn join_paths<I, T>(paths: I) -> Result<OsString, JoinPathsError>
 159     where I: Iterator<Item=T>, T: AsRef<OsStr>
 160 {
 161     let mut joined = Vec::new();
 162     let sep = b':';
 163
 164     for (i, path) in paths.enumerate() {
 165         let path = path.as_ref().as_bytes();
 166         if i > 0 { joined.push(sep) }
 167         if path.contains(&sep) {
 168             return Err(JoinPathsError)
 169         }
 170         joined.extend_from_slice(path);
 171     }
 172     Ok(OsStringExt::from_vec(joined))
 173 }
 174
 175 impl fmt::Display for JoinPathsError {
 176     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
 177         "path segment contains separator `:`".fmt(f)
 178     }
 179 }
 180
 181 impl StdError for JoinPathsError {
 182     fn description(&self) -> &str { "failed to join paths" }
 183 }
 184
 185 #[cfg(target_os = "freebsd")]
 186 pub fn current_exe() -> io::Result<PathBuf> {
 187     unsafe {
 188         let mut mib = [libc::CTL_KERN as c_int,
 189                        libc::KERN_PROC as c_int,
 190                        libc::KERN_PROC_PATHNAME as c_int,
 191                        -1 as c_int];
 192         let mut sz: libc::size_t = 0;
 193         cvt(libc::sysctl(mib.as_mut_ptr(), mib.len() as ::libc::c_uint,
 194                          ptr::null_mut(), &mut sz, ptr::null_mut(),
 195                          0 as libc::size_t))?;
 196         if sz == 0 {
 197             return Err(io::Error::last_os_error())
 198         }
 199         let mut v: Vec<u8> = Vec::with_capacity(sz as usize);
 200         cvt(libc::sysctl(mib.as_mut_ptr(), mib.len() as ::libc::c_uint,
 201                          v.as_mut_ptr() as *mut libc::c_void, &mut sz,
 202                          ptr::null_mut(), 0 as libc::size_t))?;
 203         if sz == 0 {
 204             return Err(io::Error::last_os_error());
 205         }
 206         v.set_len(sz as usize - 1); // chop off trailing NUL
 207         Ok(PathBuf::from(OsString::from_vec(v)))
 208     }
 209 }
 210
 211 #[cfg(target_os = "dragonfly")]
 212 pub fn current_exe() -> io::Result<PathBuf> {
 213     ::fs::read_link("/proc/curproc/file")
 214 }
 215
 216 #[cfg(target_os = "netbsd")]
 217 pub fn current_exe() -> io::Result<PathBuf> {
 218     ::fs::read_link("/proc/curproc/exe")
 219 }
 220
 221 #[cfg(any(target_os = "bitrig", target_os = "openbsd"))]
 222 pub fn current_exe() -> io::Result<PathBuf> {
 223     unsafe {
 224         let mut mib = [libc::CTL_KERN,
 225                        libc::KERN_PROC_ARGS,
 226                        libc::getpid(),
 227                        libc::KERN_PROC_ARGV];
 228         let mib = mib.as_mut_ptr();
 229         let mut argv_len = 0;
 230         cvt(libc::sysctl(mib, 4, 0 as *mut _, &mut argv_len,
 231                          0 as *mut _, 0))?;
 232         let mut argv = Vec::<*const libc::c_char>::with_capacity(argv_len as usize);
 233         cvt(libc::sysctl(mib, 4, argv.as_mut_ptr() as *mut _,
 234                          &mut argv_len, 0 as *mut _, 0))?;
 235         argv.set_len(argv_len as usize);
 236         if argv[0].is_null() {
 237             return Err(io::Error::new(io::ErrorKind::Other,
 238                                       "no current exe available"))
 239         }
 240         let argv0 = CStr::from_ptr(argv[0]).to_bytes();
 241         if argv0[0] == b'.' || argv0.iter().any(|b| *b == b'/') {
 242             ::fs::canonicalize(OsStr::from_bytes(argv0))
 243         } else {
 244             Ok(PathBuf::from(OsStr::from_bytes(argv0)))
 245         }
 246     }
 247 }
 248
 249 #[cfg(any(target_os = "linux", target_os = "android", target_os = "emscripten"))]
 250 pub fn current_exe() -> io::Result<PathBuf> {
 251     ::fs::read_link("/proc/self/exe")
 252 }
 253
 254 #[cfg(any(target_os = "macos", target_os = "ios"))]
 255 pub fn current_exe() -> io::Result<PathBuf> {
 256     extern {
 257         fn _NSGetExecutablePath(buf: *mut libc::c_char,
 258                                 bufsize: *mut u32) -> libc::c_int;
 259     }
 260     unsafe {
 261         let mut sz: u32 = 0;
 262         _NSGetExecutablePath(ptr::null_mut(), &mut sz);
 263         if sz == 0 { return Err(io::Error::last_os_error()); }
 264         let mut v: Vec<u8> = Vec::with_capacity(sz as usize);
 265         let err = _NSGetExecutablePath(v.as_mut_ptr() as *mut i8, &mut sz);
 266         if err != 0 { return Err(io::Error::last_os_error()); }
 267         v.set_len(sz as usize - 1); // chop off trailing NUL
 268         Ok(PathBuf::from(OsString::from_vec(v)))
 269     }
 270 }
 271
 272 #[cfg(any(target_os = "solaris"))]
 273 pub fn current_exe() -> io::Result<PathBuf> {
 274     extern {
 275         fn getexecname() -> *const c_char;
 276     }
 277     unsafe {
 278         let path = getexecname();
 279         if path.is_null() {
 280             Err(io::Error::last_os_error())
 281         } else {
 282             let filename = CStr::from_ptr(path).to_bytes();
 283             let path = PathBuf::from(<OsStr as OsStrExt>::from_bytes(filename));
 284
 285             // Prepend a current working directory to the path if
 286             // it doesn't contain an absolute pathname.
 287             if filename[0] == b'/' {
 288                 Ok(path)
 289             } else {
 290                 getcwd().map(|cwd| cwd.join(path))
 291             }
 292         }
 293     }
 294 }
 295
 296 pub struct Args {
 297     iter: vec::IntoIter<OsString>,
 298     _dont_send_or_sync_me: *mut (),
 299 }
 300
 301 impl Iterator for Args {
 302     type Item = OsString;
 303     fn next(&mut self) -> Option<OsString> { self.iter.next() }
 304     fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() }
 305 }
 306
 307 impl ExactSizeIterator for Args {
 308     fn len(&self) -> usize { self.iter.len() }
 309 }
 310
 311 /// Returns the command line arguments
 312 ///
 313 /// Returns a list of the command line arguments.
 314 #[cfg(target_os = "macos")]
 315 pub fn args() -> Args {
 316     extern {
 317         // These functions are in crt_externs.h.
 318         fn _NSGetArgc() -> *mut c_int;
 319         fn _NSGetArgv() -> *mut *mut *mut c_char;
 320     }
 321
 322     let vec = unsafe {
 323         let (argc, argv) = (*_NSGetArgc() as isize,
 324                             *_NSGetArgv() as *const *const c_char);
 325         (0.. argc as isize).map(|i| {
 326             let bytes = CStr::from_ptr(*argv.offset(i)).to_bytes().to_vec();
 327             OsStringExt::from_vec(bytes)
 328         }).collect::<Vec<_>>()
 329     };
 330     Args {
 331         iter: vec.into_iter(),
 332         _dont_send_or_sync_me: ptr::null_mut(),
 333     }
 334 }
 335
 336 // As _NSGetArgc and _NSGetArgv aren't mentioned in iOS docs
 337 // and use underscores in their names - they're most probably
 338 // are considered private and therefore should be avoided
 339 // Here is another way to get arguments using Objective C
 340 // runtime
 341 //
 342 // In general it looks like:
 343 // res = Vec::new()
 344 // let args = [[NSProcessInfo processInfo] arguments]
 345 // for i in (0..[args count])
 346 //      res.push([args objectAtIndex:i])
 347 // res
 348 #[cfg(target_os = "ios")]
 349 pub fn args() -> Args {
 350     use mem;
 351
 352     extern {
 353         fn sel_registerName(name: *const libc::c_uchar) -> Sel;
 354         fn objc_msgSend(obj: NsId, sel: Sel, ...) -> NsId;
 355         fn objc_getClass(class_name: *const libc::c_uchar) -> NsId;
 356     }
 357
 358     #[link(name = "Foundation", kind = "framework")]
 359     #[link(name = "objc")]
 360     #[cfg(not(cargobuild))]
 361     extern {}
 362
 363     type Sel = *const libc::c_void;
 364     type NsId = *const libc::c_void;
 365
 366     let mut res = Vec::new();
 367
 368     unsafe {
 369         let process_info_sel = sel_registerName("processInfo\0".as_ptr());
 370         let arguments_sel = sel_registerName("arguments\0".as_ptr());
 371         let utf8_sel = sel_registerName("UTF8String\0".as_ptr());
 372         let count_sel = sel_registerName("count\0".as_ptr());
 373         let object_at_sel = sel_registerName("objectAtIndex:\0".as_ptr());
 374
 375         let klass = objc_getClass("NSProcessInfo\0".as_ptr());
 376         let info = objc_msgSend(klass, process_info_sel);
 377         let args = objc_msgSend(info, arguments_sel);
 378
 379         let cnt: usize = mem::transmute(objc_msgSend(args, count_sel));
 380         for i in 0..cnt {
 381             let tmp = objc_msgSend(args, object_at_sel, i);
 382             let utf_c_str: *const libc::c_char =
 383                 mem::transmute(objc_msgSend(tmp, utf8_sel));
 384             let bytes = CStr::from_ptr(utf_c_str).to_bytes();
 385             res.push(OsString::from(str::from_utf8(bytes).unwrap()))
 386         }
 387     }
 388
 389     Args { iter: res.into_iter(), _dont_send_or_sync_me: ptr::null_mut() }
 390 }
 391
 392 #[cfg(any(target_os = "linux",
 393           target_os = "android",
 394           target_os = "freebsd",
 395           target_os = "dragonfly",
 396           target_os = "bitrig",
 397           target_os = "netbsd",
 398           target_os = "openbsd",
 399           target_os = "solaris",
 400           target_os = "nacl",
 401           target_os = "emscripten"))]
 402 pub fn args() -> Args {
 403     use sys_common;
 404     let bytes = sys_common::args::clone().unwrap_or(Vec::new());
 405     let v: Vec<OsString> = bytes.into_iter().map(|v| {
 406         OsStringExt::from_vec(v)
 407     }).collect();
 408     Args { iter: v.into_iter(), _dont_send_or_sync_me: ptr::null_mut() }
 409 }
 410
 411 pub struct Env {
 412     iter: vec::IntoIter<(OsString, OsString)>,
 413     _dont_send_or_sync_me: *mut (),
 414 }
 415
 416 impl Iterator for Env {
 417     type Item = (OsString, OsString);
 418     fn next(&mut self) -> Option<(OsString, OsString)> { self.iter.next() }
 419     fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() }
 420 }
 421
 422 #[cfg(target_os = "macos")]
 423 pub unsafe fn environ() -> *mut *const *const c_char {
 424     extern { fn _NSGetEnviron() -> *mut *const *const c_char; }
 425     _NSGetEnviron()
 426 }
 427
 428 #[cfg(not(target_os = "macos"))]
 429 pub unsafe fn environ() -> *mut *const *const c_char {
 430     extern { static mut environ: *const *const c_char; }
 431     &mut environ
 432 }
 433
 434 /// Returns a vector of (variable, value) byte-vector pairs for all the
 435 /// environment variables of the current process.
 436 pub fn env() -> Env {
 437     let _g = ENV_LOCK.lock();
 438     return unsafe {
 439         let mut environ = *environ();
 440         if environ == ptr::null() {
 441             panic!("os::env() failure getting env string from OS: {}",
 442                    io::Error::last_os_error());
 443         }
 444         let mut result = Vec::new();
 445         while *environ != ptr::null() {
 446             if let Some(key_value) = parse(CStr::from_ptr(*environ).to_bytes()) {
 447                 result.push(key_value);
 448             }
 449             environ = environ.offset(1);
 450         }
 451         Env { iter: result.into_iter(), _dont_send_or_sync_me: ptr::null_mut() }
 452     };
 453
 454     fn parse(input: &[u8]) -> Option<(OsString, OsString)> {
 455         // Strategy (copied from glibc): Variable name and value are separated
 456         // by an ASCII equals sign '='. Since a variable name must not be
 457         // empty, allow variable names starting with an equals sign. Skip all
 458         // malformed lines.
 459         if input.is_empty() {
 460             return None;
 461         }
 462         let pos = memchr::memchr(b'=', &input[1..]).map(|p| p + 1);
 463         pos.map(|p| (
 464             OsStringExt::from_vec(input[..p].to_vec()),
 465             OsStringExt::from_vec(input[p+1..].to_vec()),
 466         ))
 467     }
 468 }
 469
 470 pub fn getenv(k: &OsStr) -> io::Result<Option<OsString>> {
 471     // environment variables with a nul byte can't be set, so their value is
 472     // always None as well
 473     let k = CString::new(k.as_bytes())?;
 474     let _g = ENV_LOCK.lock();
 475     Ok(unsafe {
 476         let s = libc::getenv(k.as_ptr()) as *const _;
 477         if s.is_null() {
 478             None
 479         } else {
 480             Some(OsStringExt::from_vec(CStr::from_ptr(s).to_bytes().to_vec()))
 481         }
 482     })
 483 }
 484
 485 pub fn setenv(k: &OsStr, v: &OsStr) -> io::Result<()> {
 486     let k = CString::new(k.as_bytes())?;
 487     let v = CString::new(v.as_bytes())?;
 488     let _g = ENV_LOCK.lock();
 489     cvt(unsafe {
 490         libc::setenv(k.as_ptr(), v.as_ptr(), 1)
 491     }).map(|_| ())
 492 }
 493
 494 pub fn unsetenv(n: &OsStr) -> io::Result<()> {
 495     let nbuf = CString::new(n.as_bytes())?;
 496     let _g = ENV_LOCK.lock();
 497     cvt(unsafe {
 498         libc::unsetenv(nbuf.as_ptr())
 499     }).map(|_| ())
 500 }
 501
 502 pub fn page_size() -> usize {
 503     unsafe {
 504         libc::sysconf(libc::_SC_PAGESIZE) as usize
 505     }
 506 }
 507
 508 pub fn temp_dir() -> PathBuf {
 509     ::env::var_os("TMPDIR").map(PathBuf::from).unwrap_or_else(|| {
 510         if cfg!(target_os = "android") {
 511             PathBuf::from("/data/local/tmp")
 512         } else {
 513             PathBuf::from("/tmp")
 514         }
 515     })
 516 }
 517
 518 pub fn home_dir() -> Option<PathBuf> {
 519     return ::env::var_os("HOME").or_else(|| unsafe {
 520         fallback()
 521     }).map(PathBuf::from);
 522
 523     #[cfg(any(target_os = "android",
 524               target_os = "ios",
 525               target_os = "nacl"))]
 526     unsafe fn fallback() -> Option<OsString> { None }
 527     #[cfg(not(any(target_os = "android",
 528                   target_os = "ios",
 529                   target_os = "nacl")))]
 530     unsafe fn fallback() -> Option<OsString> {
 531         #[cfg(not(target_os = "solaris"))]
 532         unsafe fn getpwduid_r(me: libc::uid_t, passwd: &mut libc::passwd,
 533                               buf: &mut Vec<c_char>) -> Option<()> {
 534             let mut result = ptr::null_mut();
 535             match libc::getpwuid_r(me, passwd, buf.as_mut_ptr(),
 536                                    buf.capacity() as libc::size_t,
 537                                    &mut result) {
 538                 0 if !result.is_null() => Some(()),
 539                 _ => None
 540             }
 541         }
 542
 543         #[cfg(target_os = "solaris")]
 544         unsafe fn getpwduid_r(me: libc::uid_t, passwd: &mut libc::passwd,
 545                               buf: &mut Vec<c_char>) -> Option<()> {
 546             // getpwuid_r semantics is different on Illumos/Solaris:
 547             // http://illumos.org/man/3c/getpwuid_r
 548             let result = libc::getpwuid_r(me, passwd, buf.as_mut_ptr(),
 549                                           buf.capacity() as libc::size_t);
 550             if result.is_null() { None } else { Some(()) }
 551         }
 552
 553         let amt = match libc::sysconf(libc::_SC_GETPW_R_SIZE_MAX) {
 554             n if n < 0 => 512 as usize,
 555             n => n as usize,
 556         };
 557         let me = libc::getuid();
 558         loop {
 559             let mut buf = Vec::with_capacity(amt);
 560             let mut passwd: libc::passwd = mem::zeroed();
 561
 562             if getpwduid_r(me, &mut passwd, &mut buf).is_some() {
 563                 let ptr = passwd.pw_dir as *const _;
 564                 let bytes = CStr::from_ptr(ptr).to_bytes().to_vec();
 565                 return Some(OsStringExt::from_vec(bytes))
 566             } else {
 567                 return None;
 568             }
 569         }
 570     }
 571 }
 572
 573 pub fn exit(code: i32) -> ! {
 574     unsafe { libc::exit(code as c_int) }
 575 }