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 path::{self, PathBuf};
  26 use ptr;
  27 use slice;
  28 use str;
  29 use sys::c;
  30 use sys::fd;
  31 use vec;
  32
  33 const TMPBUF_SZ: usize = 128;
  34
  35 /// Returns the platform-specific value of errno
  36 pub fn errno() -> i32 {
  37     #[cfg(any(target_os = "macos",
  38               target_os = "ios",
  39               target_os = "freebsd"))]
  40     unsafe fn errno_location() -> *const c_int {
  41         extern { fn __error() -> *const c_int; }
  42         __error()
  43     }
  44
  45     #[cfg(target_os = "dragonfly")]
  46     unsafe fn errno_location() -> *const c_int {
  47         extern { fn __dfly_error() -> *const c_int; }
  48         __dfly_error()
  49     }
  50
  51     #[cfg(any(target_os = "bitrig", target_os = "netbsd", target_os = "openbsd"))]
  52     unsafe fn errno_location() -> *const c_int {
  53         extern { fn __errno() -> *const c_int; }
  54         __errno()
  55     }
  56
  57     #[cfg(any(target_os = "linux", target_os = "android"))]
  58     unsafe fn errno_location() -> *const c_int {
  59         extern { fn __errno_location() -> *const c_int; }
  60         __errno_location()
  61     }
  62
  63     unsafe {
  64         (*errno_location()) as i32
  65     }
  66 }
  67
  68 /// Gets a detailed string description for the given error number.
  69 pub fn error_string(errno: i32) -> String {
  70     #[cfg(target_os = "linux")]
  71     extern {
  72         #[link_name = "__xpg_strerror_r"]
  73         fn strerror_r(errnum: c_int, buf: *mut c_char,
  74                       buflen: libc::size_t) -> c_int;
  75     }
  76     #[cfg(not(target_os = "linux"))]
  77     extern {
  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 = try!(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.push_all(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         use libc::funcs::bsd44::*;
 189         use libc::consts::os::extra::*;
 190         let mut mib = [CTL_KERN as c_int,
 191                        KERN_PROC as c_int,
 192                        KERN_PROC_PATHNAME as c_int,
 193                        -1 as c_int];
 194         let mut sz: libc::size_t = 0;
 195         let err = sysctl(mib.as_mut_ptr(), mib.len() as ::libc::c_uint,
 196                          ptr::null_mut(), &mut sz, ptr::null_mut(),
 197                          0 as libc::size_t);
 198         if err != 0 { return Err(io::Error::last_os_error()); }
 199         if sz == 0 { return Err(io::Error::last_os_error()); }
 200         let mut v: Vec<u8> = Vec::with_capacity(sz as usize);
 201         let err = sysctl(mib.as_mut_ptr(), mib.len() as ::libc::c_uint,
 202                          v.as_mut_ptr() as *mut libc::c_void, &mut sz,
 203                          ptr::null_mut(), 0 as libc::size_t);
 204         if err != 0 { return Err(io::Error::last_os_error()); }
 205         if sz == 0 { return Err(io::Error::last_os_error()); }
 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     use sync::StaticMutex;
 224     static LOCK: StaticMutex = StaticMutex::new();
 225
 226     extern {
 227         fn rust_current_exe() -> *const c_char;
 228     }
 229
 230     let _guard = LOCK.lock();
 231
 232     unsafe {
 233         let v = rust_current_exe();
 234         if v.is_null() {
 235             Err(io::Error::last_os_error())
 236         } else {
 237             let vec = CStr::from_ptr(v).to_bytes().to_vec();
 238             Ok(PathBuf::from(OsString::from_vec(vec)))
 239         }
 240     }
 241 }
 242
 243 #[cfg(any(target_os = "linux", target_os = "android"))]
 244 pub fn current_exe() -> io::Result<PathBuf> {
 245     ::fs::read_link("/proc/self/exe")
 246 }
 247
 248 #[cfg(any(target_os = "macos", target_os = "ios"))]
 249 pub fn current_exe() -> io::Result<PathBuf> {
 250     unsafe {
 251         use libc::funcs::extra::_NSGetExecutablePath;
 252         let mut sz: u32 = 0;
 253         _NSGetExecutablePath(ptr::null_mut(), &mut sz);
 254         if sz == 0 { return Err(io::Error::last_os_error()); }
 255         let mut v: Vec<u8> = Vec::with_capacity(sz as usize);
 256         let err = _NSGetExecutablePath(v.as_mut_ptr() as *mut i8, &mut sz);
 257         if err != 0 { return Err(io::Error::last_os_error()); }
 258         v.set_len(sz as usize - 1); // chop off trailing NUL
 259         Ok(PathBuf::from(OsString::from_vec(v)))
 260     }
 261 }
 262
 263 pub struct Args {
 264     iter: vec::IntoIter<OsString>,
 265     _dont_send_or_sync_me: *mut (),
 266 }
 267
 268 impl Iterator for Args {
 269     type Item = OsString;
 270     fn next(&mut self) -> Option<OsString> { self.iter.next() }
 271     fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() }
 272 }
 273
 274 impl ExactSizeIterator for Args {
 275     fn len(&self) -> usize { self.iter.len() }
 276 }
 277
 278 /// Returns the command line arguments
 279 ///
 280 /// Returns a list of the command line arguments.
 281 #[cfg(target_os = "macos")]
 282 pub fn args() -> Args {
 283     extern {
 284         // These functions are in crt_externs.h.
 285         fn _NSGetArgc() -> *mut c_int;
 286         fn _NSGetArgv() -> *mut *mut *mut c_char;
 287     }
 288
 289     let vec = unsafe {
 290         let (argc, argv) = (*_NSGetArgc() as isize,
 291                             *_NSGetArgv() as *const *const c_char);
 292         (0.. argc as isize).map(|i| {
 293             let bytes = CStr::from_ptr(*argv.offset(i)).to_bytes().to_vec();
 294             OsStringExt::from_vec(bytes)
 295         }).collect::<Vec<_>>()
 296     };
 297     Args {
 298         iter: vec.into_iter(),
 299         _dont_send_or_sync_me: ptr::null_mut(),
 300     }
 301 }
 302
 303 // As _NSGetArgc and _NSGetArgv aren't mentioned in iOS docs
 304 // and use underscores in their names - they're most probably
 305 // are considered private and therefore should be avoided
 306 // Here is another way to get arguments using Objective C
 307 // runtime
 308 //
 309 // In general it looks like:
 310 // res = Vec::new()
 311 // let args = [[NSProcessInfo processInfo] arguments]
 312 // for i in (0..[args count])
 313 //      res.push([args objectAtIndex:i])
 314 // res
 315 #[cfg(target_os = "ios")]
 316 pub fn args() -> Args {
 317     use mem;
 318
 319     #[link(name = "objc")]
 320     extern {
 321         fn sel_registerName(name: *const libc::c_uchar) -> Sel;
 322         fn objc_msgSend(obj: NsId, sel: Sel, ...) -> NsId;
 323         fn objc_getClass(class_name: *const libc::c_uchar) -> NsId;
 324     }
 325
 326     #[link(name = "Foundation", kind = "framework")]
 327     extern {}
 328
 329     type Sel = *const libc::c_void;
 330     type NsId = *const libc::c_void;
 331
 332     let mut res = Vec::new();
 333
 334     unsafe {
 335         let process_info_sel = sel_registerName("processInfo\0".as_ptr());
 336         let arguments_sel = sel_registerName("arguments\0".as_ptr());
 337         let utf8_sel = sel_registerName("UTF8String\0".as_ptr());
 338         let count_sel = sel_registerName("count\0".as_ptr());
 339         let object_at_sel = sel_registerName("objectAtIndex:\0".as_ptr());
 340
 341         let klass = objc_getClass("NSProcessInfo\0".as_ptr());
 342         let info = objc_msgSend(klass, process_info_sel);
 343         let args = objc_msgSend(info, arguments_sel);
 344
 345         let cnt: usize = mem::transmute(objc_msgSend(args, count_sel));
 346         for i in 0..cnt {
 347             let tmp = objc_msgSend(args, object_at_sel, i);
 348             let utf_c_str: *const libc::c_char =
 349                 mem::transmute(objc_msgSend(tmp, utf8_sel));
 350             let bytes = CStr::from_ptr(utf_c_str).to_bytes();
 351             res.push(OsString::from(str::from_utf8(bytes).unwrap()))
 352         }
 353     }
 354
 355     Args { iter: res.into_iter(), _dont_send_or_sync_me: ptr::null_mut() }
 356 }
 357
 358 #[cfg(any(target_os = "linux",
 359           target_os = "android",
 360           target_os = "freebsd",
 361           target_os = "dragonfly",
 362           target_os = "bitrig",
 363           target_os = "netbsd",
 364           target_os = "openbsd"))]
 365 pub fn args() -> Args {
 366     use sys_common;
 367     let bytes = sys_common::args::clone().unwrap_or(Vec::new());
 368     let v: Vec<OsString> = bytes.into_iter().map(|v| {
 369         OsStringExt::from_vec(v)
 370     }).collect();
 371     Args { iter: v.into_iter(), _dont_send_or_sync_me: ptr::null_mut() }
 372 }
 373
 374 pub struct Env {
 375     iter: vec::IntoIter<(OsString, OsString)>,
 376     _dont_send_or_sync_me: *mut (),
 377 }
 378
 379 impl Iterator for Env {
 380     type Item = (OsString, OsString);
 381     fn next(&mut self) -> Option<(OsString, OsString)> { self.iter.next() }
 382     fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() }
 383 }
 384
 385 #[cfg(target_os = "macos")]
 386 pub unsafe fn environ() -> *mut *const *const c_char {
 387     extern { fn _NSGetEnviron() -> *mut *const *const c_char; }
 388     _NSGetEnviron()
 389 }
 390
 391 #[cfg(not(target_os = "macos"))]
 392 pub unsafe fn environ() -> *mut *const *const c_char {
 393     extern { static mut environ: *const *const c_char; }
 394     &mut environ
 395 }
 396
 397 /// Returns a vector of (variable, value) byte-vector pairs for all the
 398 /// environment variables of the current process.
 399 pub fn env() -> Env {
 400     return unsafe {
 401         let mut environ = *environ();
 402         if environ as usize == 0 {
 403             panic!("os::env() failure getting env string from OS: {}",
 404                    io::Error::last_os_error());
 405         }
 406         let mut result = Vec::new();
 407         while *environ != ptr::null() {
 408             result.push(parse(CStr::from_ptr(*environ).to_bytes()));
 409             environ = environ.offset(1);
 410         }
 411         Env { iter: result.into_iter(), _dont_send_or_sync_me: ptr::null_mut() }
 412     };
 413
 414     fn parse(input: &[u8]) -> (OsString, OsString) {
 415         let mut it = input.splitn(2, |b| *b == b'=');
 416         let key = it.next().unwrap().to_vec();
 417         let default: &[u8] = &[];
 418         let val = it.next().unwrap_or(default).to_vec();
 419         (OsStringExt::from_vec(key), OsStringExt::from_vec(val))
 420     }
 421 }
 422
 423 pub fn getenv(k: &OsStr) -> Option<OsString> {
 424     unsafe {
 425         let s = k.to_cstring().unwrap();
 426         let s = libc::getenv(s.as_ptr()) as *const _;
 427         if s.is_null() {
 428             None
 429         } else {
 430             Some(OsStringExt::from_vec(CStr::from_ptr(s).to_bytes().to_vec()))
 431         }
 432     }
 433 }
 434
 435 pub fn setenv(k: &OsStr, v: &OsStr) {
 436     unsafe {
 437         let k = k.to_cstring().unwrap();
 438         let v = v.to_cstring().unwrap();
 439         if libc::funcs::posix01::unistd::setenv(k.as_ptr(), v.as_ptr(), 1) != 0 {
 440             panic!("failed setenv: {}", io::Error::last_os_error());
 441         }
 442     }
 443 }
 444
 445 pub fn unsetenv(n: &OsStr) {
 446     unsafe {
 447         let nbuf = n.to_cstring().unwrap();
 448         if libc::funcs::posix01::unistd::unsetenv(nbuf.as_ptr()) != 0 {
 449             panic!("failed unsetenv: {}", io::Error::last_os_error());
 450         }
 451     }
 452 }
 453
 454 pub fn page_size() -> usize {
 455     unsafe {
 456         libc::sysconf(libc::_SC_PAGESIZE) as usize
 457     }
 458 }
 459
 460 pub fn temp_dir() -> PathBuf {
 461     getenv("TMPDIR".as_ref()).map(PathBuf::from).unwrap_or_else(|| {
 462         if cfg!(target_os = "android") {
 463             PathBuf::from("/data/local/tmp")
 464         } else {
 465             PathBuf::from("/tmp")
 466         }
 467     })
 468 }
 469
 470 pub fn home_dir() -> Option<PathBuf> {
 471     return getenv("HOME".as_ref()).or_else(|| unsafe {
 472         fallback()
 473     }).map(PathBuf::from);
 474
 475     #[cfg(any(target_os = "android",
 476               target_os = "ios"))]
 477     unsafe fn fallback() -> Option<OsString> { None }
 478     #[cfg(not(any(target_os = "android",
 479                   target_os = "ios")))]
 480     unsafe fn fallback() -> Option<OsString> {
 481         let amt = match libc::sysconf(c::_SC_GETPW_R_SIZE_MAX) {
 482             n if n < 0 => 512 as usize,
 483             n => n as usize,
 484         };
 485         let me = libc::getuid();
 486         loop {
 487             let mut buf = Vec::with_capacity(amt);
 488             let mut passwd: c::passwd = mem::zeroed();
 489             let mut result = ptr::null_mut();
 490             match c::getpwuid_r(me, &mut passwd, buf.as_mut_ptr(),
 491                                 buf.capacity() as libc::size_t,
 492                                 &mut result) {
 493                 0 if !result.is_null() => {}
 494                 _ => return None
 495             }
 496             let ptr = passwd.pw_dir as *const _;
 497             let bytes = CStr::from_ptr(ptr).to_bytes().to_vec();
 498             return Some(OsStringExt::from_vec(bytes))
 499         }
 500     }
 501 }
 502
 503 pub fn exit(code: i32) -> ! {
 504     unsafe { libc::exit(code as c_int) }
 505 }