blob: 850bdfdf5b54c3bd2272bb8f282a5a7d9e69d175 [file] [log] [blame]
//! Implementation of `std::os` functionality for unix systems
#![allow(unused_imports)] // lots of cfg code here
#[cfg(test)]
mod tests;
use libc::{c_char, c_int, c_void};
use crate::error::Error as StdError;
use crate::ffi::{CStr, OsStr, OsString};
use crate::os::unix::prelude::*;
use crate::path::{self, PathBuf};
use crate::sys::common::small_c_string::run_path_with_cstr;
use crate::sys::cvt;
use crate::{fmt, io, iter, mem, ptr, slice, str};
const TMPBUF_SZ: usize = 128;
cfg_if::cfg_if! {
if #[cfg(target_os = "redox")] {
const PATH_SEPARATOR: u8 = b';';
} else {
const PATH_SEPARATOR: u8 = b':';
}
}
unsafe extern "C" {
#[cfg(not(any(target_os = "dragonfly", target_os = "vxworks", target_os = "rtems")))]
#[cfg_attr(
any(
target_os = "linux",
target_os = "emscripten",
target_os = "fuchsia",
target_os = "l4re",
target_os = "hurd",
),
link_name = "__errno_location"
)]
#[cfg_attr(
any(
target_os = "netbsd",
target_os = "openbsd",
target_os = "cygwin",
target_os = "android",
target_os = "redox",
target_os = "nuttx",
target_env = "newlib"
),
link_name = "__errno"
)]
#[cfg_attr(any(target_os = "solaris", target_os = "illumos"), link_name = "___errno")]
#[cfg_attr(target_os = "nto", link_name = "__get_errno_ptr")]
#[cfg_attr(any(target_os = "freebsd", target_vendor = "apple"), link_name = "__error")]
#[cfg_attr(target_os = "haiku", link_name = "_errnop")]
#[cfg_attr(target_os = "aix", link_name = "_Errno")]
// SAFETY: this will always return the same pointer on a given thread.
#[unsafe(ffi_const)]
pub safe fn errno_location() -> *mut c_int;
}
/// Returns the platform-specific value of errno
#[cfg(not(any(target_os = "dragonfly", target_os = "vxworks", target_os = "rtems")))]
#[inline]
pub fn errno() -> i32 {
unsafe { (*errno_location()) as i32 }
}
/// Sets the platform-specific value of errno
// needed for readdir and syscall!
#[cfg(all(not(target_os = "dragonfly"), not(target_os = "vxworks"), not(target_os = "rtems")))]
#[allow(dead_code)] // but not all target cfgs actually end up using it
#[inline]
pub fn set_errno(e: i32) {
unsafe { *errno_location() = e as c_int }
}
#[cfg(target_os = "vxworks")]
#[inline]
pub fn errno() -> i32 {
unsafe { libc::errnoGet() }
}
#[cfg(target_os = "rtems")]
#[inline]
pub fn errno() -> i32 {
unsafe extern "C" {
#[thread_local]
static _tls_errno: c_int;
}
unsafe { _tls_errno as i32 }
}
#[cfg(target_os = "dragonfly")]
#[inline]
pub fn errno() -> i32 {
unsafe extern "C" {
#[thread_local]
static errno: c_int;
}
unsafe { errno as i32 }
}
#[cfg(target_os = "dragonfly")]
#[allow(dead_code)]
#[inline]
pub fn set_errno(e: i32) {
unsafe extern "C" {
#[thread_local]
static mut errno: c_int;
}
unsafe {
errno = e;
}
}
/// Gets a detailed string description for the given error number.
pub fn error_string(errno: i32) -> String {
unsafe extern "C" {
#[cfg_attr(
all(
any(
target_os = "linux",
target_os = "hurd",
target_env = "newlib",
target_os = "cygwin"
),
not(target_env = "ohos")
),
link_name = "__xpg_strerror_r"
)]
fn strerror_r(errnum: c_int, buf: *mut c_char, buflen: libc::size_t) -> c_int;
}
let mut buf = [0 as c_char; TMPBUF_SZ];
let p = buf.as_mut_ptr();
unsafe {
if strerror_r(errno as c_int, p, buf.len()) < 0 {
panic!("strerror_r failure");
}
let p = p as *const _;
// We can't always expect a UTF-8 environment. When we don't get that luxury,
// it's better to give a low-quality error message than none at all.
String::from_utf8_lossy(CStr::from_ptr(p).to_bytes()).into()
}
}
#[cfg(target_os = "espidf")]
pub fn getcwd() -> io::Result<PathBuf> {
Ok(PathBuf::from("/"))
}
#[cfg(not(target_os = "espidf"))]
pub fn getcwd() -> io::Result<PathBuf> {
let mut buf = Vec::with_capacity(512);
loop {
unsafe {
let ptr = buf.as_mut_ptr() as *mut libc::c_char;
if !libc::getcwd(ptr, buf.capacity()).is_null() {
let len = CStr::from_ptr(buf.as_ptr() as *const libc::c_char).to_bytes().len();
buf.set_len(len);
buf.shrink_to_fit();
return Ok(PathBuf::from(OsString::from_vec(buf)));
} else {
let error = io::Error::last_os_error();
if error.raw_os_error() != Some(libc::ERANGE) {
return Err(error);
}
}
// Trigger the internal buffer resizing logic of `Vec` by requiring
// more space than the current capacity.
let cap = buf.capacity();
buf.set_len(cap);
buf.reserve(1);
}
}
}
#[cfg(target_os = "espidf")]
pub fn chdir(_p: &path::Path) -> io::Result<()> {
super::unsupported::unsupported()
}
#[cfg(not(target_os = "espidf"))]
pub fn chdir(p: &path::Path) -> io::Result<()> {
let result = run_path_with_cstr(p, &|p| unsafe { Ok(libc::chdir(p.as_ptr())) })?;
if result == 0 { Ok(()) } else { Err(io::Error::last_os_error()) }
}
pub struct SplitPaths<'a> {
iter: iter::Map<slice::Split<'a, u8, fn(&u8) -> bool>, fn(&'a [u8]) -> PathBuf>,
}
pub fn split_paths(unparsed: &OsStr) -> SplitPaths<'_> {
fn bytes_to_path(b: &[u8]) -> PathBuf {
PathBuf::from(<OsStr as OsStrExt>::from_bytes(b))
}
fn is_separator(b: &u8) -> bool {
*b == PATH_SEPARATOR
}
let unparsed = unparsed.as_bytes();
SplitPaths {
iter: unparsed
.split(is_separator as fn(&u8) -> bool)
.map(bytes_to_path as fn(&[u8]) -> PathBuf),
}
}
impl<'a> Iterator for SplitPaths<'a> {
type Item = PathBuf;
fn next(&mut self) -> Option<PathBuf> {
self.iter.next()
}
fn size_hint(&self) -> (usize, Option<usize>) {
self.iter.size_hint()
}
}
#[derive(Debug)]
pub struct JoinPathsError;
pub fn join_paths<I, T>(paths: I) -> Result<OsString, JoinPathsError>
where
I: Iterator<Item = T>,
T: AsRef<OsStr>,
{
let mut joined = Vec::new();
for (i, path) in paths.enumerate() {
let path = path.as_ref().as_bytes();
if i > 0 {
joined.push(PATH_SEPARATOR)
}
if path.contains(&PATH_SEPARATOR) {
return Err(JoinPathsError);
}
joined.extend_from_slice(path);
}
Ok(OsStringExt::from_vec(joined))
}
impl fmt::Display for JoinPathsError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
write!(f, "path segment contains separator `{}`", char::from(PATH_SEPARATOR))
}
}
impl StdError for JoinPathsError {
#[allow(deprecated)]
fn description(&self) -> &str {
"failed to join paths"
}
}
#[cfg(target_os = "aix")]
pub fn current_exe() -> io::Result<PathBuf> {
#[cfg(test)]
use realstd::env;
#[cfg(not(test))]
use crate::env;
use crate::io::ErrorKind;
let exe_path = env::args().next().ok_or(io::const_error!(
ErrorKind::NotFound,
"an executable path was not found because no arguments were provided through argv",
))?;
let path = PathBuf::from(exe_path);
if path.is_absolute() {
return path.canonicalize();
}
// Search PWD to infer current_exe.
if let Some(pstr) = path.to_str()
&& pstr.contains("/")
{
return getcwd().map(|cwd| cwd.join(path))?.canonicalize();
}
// Search PATH to infer current_exe.
if let Some(p) = env::var_os(OsStr::from_bytes("PATH".as_bytes())) {
for search_path in split_paths(&p) {
let pb = search_path.join(&path);
if pb.is_file()
&& let Ok(metadata) = crate::fs::metadata(&pb)
&& metadata.permissions().mode() & 0o111 != 0
{
return pb.canonicalize();
}
}
}
Err(io::const_error!(ErrorKind::NotFound, "an executable path was not found"))
}
#[cfg(any(target_os = "freebsd", target_os = "dragonfly"))]
pub fn current_exe() -> io::Result<PathBuf> {
unsafe {
let mut mib = [
libc::CTL_KERN as c_int,
libc::KERN_PROC as c_int,
libc::KERN_PROC_PATHNAME as c_int,
-1 as c_int,
];
let mut sz = 0;
cvt(libc::sysctl(
mib.as_mut_ptr(),
mib.len() as libc::c_uint,
ptr::null_mut(),
&mut sz,
ptr::null_mut(),
0,
))?;
if sz == 0 {
return Err(io::Error::last_os_error());
}
let mut v: Vec<u8> = Vec::with_capacity(sz);
cvt(libc::sysctl(
mib.as_mut_ptr(),
mib.len() as libc::c_uint,
v.as_mut_ptr() as *mut libc::c_void,
&mut sz,
ptr::null_mut(),
0,
))?;
if sz == 0 {
return Err(io::Error::last_os_error());
}
v.set_len(sz - 1); // chop off trailing NUL
Ok(PathBuf::from(OsString::from_vec(v)))
}
}
#[cfg(target_os = "netbsd")]
pub fn current_exe() -> io::Result<PathBuf> {
fn sysctl() -> io::Result<PathBuf> {
unsafe {
let mib = [libc::CTL_KERN, libc::KERN_PROC_ARGS, -1, libc::KERN_PROC_PATHNAME];
let mut path_len: usize = 0;
cvt(libc::sysctl(
mib.as_ptr(),
mib.len() as libc::c_uint,
ptr::null_mut(),
&mut path_len,
ptr::null(),
0,
))?;
if path_len <= 1 {
return Err(io::const_error!(
io::ErrorKind::Uncategorized,
"KERN_PROC_PATHNAME sysctl returned zero-length string",
));
}
let mut path: Vec<u8> = Vec::with_capacity(path_len);
cvt(libc::sysctl(
mib.as_ptr(),
mib.len() as libc::c_uint,
path.as_ptr() as *mut libc::c_void,
&mut path_len,
ptr::null(),
0,
))?;
path.set_len(path_len - 1); // chop off NUL
Ok(PathBuf::from(OsString::from_vec(path)))
}
}
fn procfs() -> io::Result<PathBuf> {
let curproc_exe = path::Path::new("/proc/curproc/exe");
if curproc_exe.is_file() {
return crate::fs::read_link(curproc_exe);
}
Err(io::const_error!(
io::ErrorKind::Uncategorized,
"/proc/curproc/exe doesn't point to regular file.",
))
}
sysctl().or_else(|_| procfs())
}
#[cfg(target_os = "openbsd")]
pub fn current_exe() -> io::Result<PathBuf> {
unsafe {
let mut mib = [libc::CTL_KERN, libc::KERN_PROC_ARGS, libc::getpid(), libc::KERN_PROC_ARGV];
let mib = mib.as_mut_ptr();
let mut argv_len = 0;
cvt(libc::sysctl(mib, 4, ptr::null_mut(), &mut argv_len, ptr::null_mut(), 0))?;
let mut argv = Vec::<*const libc::c_char>::with_capacity(argv_len as usize);
cvt(libc::sysctl(mib, 4, argv.as_mut_ptr() as *mut _, &mut argv_len, ptr::null_mut(), 0))?;
argv.set_len(argv_len as usize);
if argv[0].is_null() {
return Err(io::const_error!(io::ErrorKind::Uncategorized, "no current exe available"));
}
let argv0 = CStr::from_ptr(argv[0]).to_bytes();
if argv0[0] == b'.' || argv0.iter().any(|b| *b == b'/') {
crate::fs::canonicalize(OsStr::from_bytes(argv0))
} else {
Ok(PathBuf::from(OsStr::from_bytes(argv0)))
}
}
}
#[cfg(any(
target_os = "linux",
target_os = "cygwin",
target_os = "hurd",
target_os = "android",
target_os = "nuttx",
target_os = "emscripten"
))]
pub fn current_exe() -> io::Result<PathBuf> {
match crate::fs::read_link("/proc/self/exe") {
Err(ref e) if e.kind() == io::ErrorKind::NotFound => Err(io::const_error!(
io::ErrorKind::Uncategorized,
"no /proc/self/exe available. Is /proc mounted?",
)),
other => other,
}
}
#[cfg(target_os = "nto")]
pub fn current_exe() -> io::Result<PathBuf> {
let mut e = crate::fs::read("/proc/self/exefile")?;
// Current versions of QNX Neutrino provide a null-terminated path.
// Ensure the trailing null byte is not returned here.
if let Some(0) = e.last() {
e.pop();
}
Ok(PathBuf::from(OsString::from_vec(e)))
}
#[cfg(target_vendor = "apple")]
pub fn current_exe() -> io::Result<PathBuf> {
unsafe {
let mut sz: u32 = 0;
#[expect(deprecated)]
libc::_NSGetExecutablePath(ptr::null_mut(), &mut sz);
if sz == 0 {
return Err(io::Error::last_os_error());
}
let mut v: Vec<u8> = Vec::with_capacity(sz as usize);
#[expect(deprecated)]
let err = libc::_NSGetExecutablePath(v.as_mut_ptr() as *mut i8, &mut sz);
if err != 0 {
return Err(io::Error::last_os_error());
}
v.set_len(sz as usize - 1); // chop off trailing NUL
Ok(PathBuf::from(OsString::from_vec(v)))
}
}
#[cfg(any(target_os = "solaris", target_os = "illumos"))]
pub fn current_exe() -> io::Result<PathBuf> {
if let Ok(path) = crate::fs::read_link("/proc/self/path/a.out") {
Ok(path)
} else {
unsafe {
let path = libc::getexecname();
if path.is_null() {
Err(io::Error::last_os_error())
} else {
let filename = CStr::from_ptr(path).to_bytes();
let path = PathBuf::from(<OsStr as OsStrExt>::from_bytes(filename));
// Prepend a current working directory to the path if
// it doesn't contain an absolute pathname.
if filename[0] == b'/' { Ok(path) } else { getcwd().map(|cwd| cwd.join(path)) }
}
}
}
}
#[cfg(target_os = "haiku")]
pub fn current_exe() -> io::Result<PathBuf> {
let mut name = vec![0; libc::PATH_MAX as usize];
unsafe {
let result = libc::find_path(
crate::ptr::null_mut(),
libc::path_base_directory::B_FIND_PATH_IMAGE_PATH,
crate::ptr::null_mut(),
name.as_mut_ptr(),
name.len(),
);
if result != libc::B_OK {
use crate::io::ErrorKind;
Err(io::const_error!(ErrorKind::Uncategorized, "error getting executable path"))
} else {
// find_path adds the null terminator.
let name = CStr::from_ptr(name.as_ptr()).to_bytes();
Ok(PathBuf::from(OsStr::from_bytes(name)))
}
}
}
#[cfg(target_os = "redox")]
pub fn current_exe() -> io::Result<PathBuf> {
crate::fs::read_to_string("/scheme/sys/exe").map(PathBuf::from)
}
#[cfg(target_os = "rtems")]
pub fn current_exe() -> io::Result<PathBuf> {
crate::fs::read_to_string("sys:exe").map(PathBuf::from)
}
#[cfg(target_os = "l4re")]
pub fn current_exe() -> io::Result<PathBuf> {
use crate::io::ErrorKind;
Err(io::const_error!(ErrorKind::Unsupported, "not yet implemented!"))
}
#[cfg(target_os = "vxworks")]
pub fn current_exe() -> io::Result<PathBuf> {
#[cfg(test)]
use realstd::env;
#[cfg(not(test))]
use crate::env;
let exe_path = env::args().next().unwrap();
let path = path::Path::new(&exe_path);
path.canonicalize()
}
#[cfg(any(target_os = "espidf", target_os = "horizon", target_os = "vita"))]
pub fn current_exe() -> io::Result<PathBuf> {
super::unsupported::unsupported()
}
#[cfg(target_os = "fuchsia")]
pub fn current_exe() -> io::Result<PathBuf> {
#[cfg(test)]
use realstd::env;
#[cfg(not(test))]
use crate::env;
use crate::io::ErrorKind;
let exe_path = env::args().next().ok_or(io::const_error!(
ErrorKind::Uncategorized,
"an executable path was not found because no arguments were provided through argv",
))?;
let path = PathBuf::from(exe_path);
// Prepend the current working directory to the path if it's not absolute.
if !path.is_absolute() { getcwd().map(|cwd| cwd.join(path)) } else { Ok(path) }
}
#[cfg(not(target_os = "espidf"))]
pub fn page_size() -> usize {
unsafe { libc::sysconf(libc::_SC_PAGESIZE) as usize }
}
// Returns the value for [`confstr(key, ...)`][posix_confstr]. Currently only
// used on Darwin, but should work on any unix (in case we need to get
// `_CS_PATH` or `_CS_V[67]_ENV` in the future).
//
// [posix_confstr]:
// https://pubs.opengroup.org/onlinepubs/9699919799/functions/confstr.html
//
// FIXME: Support `confstr` in Miri.
#[cfg(all(target_vendor = "apple", not(miri)))]
fn confstr(key: c_int, size_hint: Option<usize>) -> io::Result<OsString> {
let mut buf: Vec<u8> = Vec::with_capacity(0);
let mut bytes_needed_including_nul = size_hint
.unwrap_or_else(|| {
// Treat "None" as "do an extra call to get the length". In theory
// we could move this into the loop below, but it's hard to do given
// that it isn't 100% clear if it's legal to pass 0 for `len` when
// the buffer isn't null.
unsafe { libc::confstr(key, core::ptr::null_mut(), 0) }
})
.max(1);
// If the value returned by `confstr` is greater than the len passed into
// it, then the value was truncated, meaning we need to retry. Note that
// while `confstr` results don't seem to change for a process, it's unclear
// if this is guaranteed anywhere, so looping does seem required.
while bytes_needed_including_nul > buf.capacity() {
// We write into the spare capacity of `buf`. This lets us avoid
// changing buf's `len`, which both simplifies `reserve` computation,
// allows working with `Vec<u8>` instead of `Vec<MaybeUninit<u8>>`, and
// may avoid a copy, since the Vec knows that none of the bytes are needed
// when reallocating (well, in theory anyway).
buf.reserve(bytes_needed_including_nul);
// `confstr` returns
// - 0 in the case of errors: we break and return an error.
// - The number of bytes written, iff the provided buffer is enough to
// hold the entire value: we break and return the data in `buf`.
// - Otherwise, the number of bytes needed (including nul): we go
// through the loop again.
bytes_needed_including_nul =
unsafe { libc::confstr(key, buf.as_mut_ptr().cast::<c_char>(), buf.capacity()) };
}
// `confstr` returns 0 in the case of an error.
if bytes_needed_including_nul == 0 {
return Err(io::Error::last_os_error());
}
// Safety: `confstr(..., buf.as_mut_ptr(), buf.capacity())` returned a
// non-zero value, meaning `bytes_needed_including_nul` bytes were
// initialized.
unsafe {
buf.set_len(bytes_needed_including_nul);
// Remove the NUL-terminator.
let last_byte = buf.pop();
// ... and smoke-check that it *was* a NUL-terminator.
assert_eq!(last_byte, Some(0), "`confstr` provided a string which wasn't nul-terminated");
};
Ok(OsString::from_vec(buf))
}
#[cfg(all(target_vendor = "apple", not(miri)))]
fn darwin_temp_dir() -> PathBuf {
confstr(libc::_CS_DARWIN_USER_TEMP_DIR, Some(64)).map(PathBuf::from).unwrap_or_else(|_| {
// It failed for whatever reason (there are several possible reasons),
// so return the global one.
PathBuf::from("/tmp")
})
}
pub fn temp_dir() -> PathBuf {
crate::env::var_os("TMPDIR").map(PathBuf::from).unwrap_or_else(|| {
cfg_if::cfg_if! {
if #[cfg(all(target_vendor = "apple", not(miri)))] {
darwin_temp_dir()
} else if #[cfg(target_os = "android")] {
PathBuf::from("/data/local/tmp")
} else {
PathBuf::from("/tmp")
}
}
})
}
pub fn home_dir() -> Option<PathBuf> {
return crate::env::var_os("HOME").or_else(|| unsafe { fallback() }).map(PathBuf::from);
#[cfg(any(
target_os = "android",
target_os = "emscripten",
target_os = "redox",
target_os = "vxworks",
target_os = "espidf",
target_os = "horizon",
target_os = "vita",
target_os = "nuttx",
all(target_vendor = "apple", not(target_os = "macos")),
))]
unsafe fn fallback() -> Option<OsString> {
None
}
#[cfg(not(any(
target_os = "android",
target_os = "emscripten",
target_os = "redox",
target_os = "vxworks",
target_os = "espidf",
target_os = "horizon",
target_os = "vita",
target_os = "nuttx",
all(target_vendor = "apple", not(target_os = "macos")),
)))]
unsafe fn fallback() -> Option<OsString> {
let amt = match libc::sysconf(libc::_SC_GETPW_R_SIZE_MAX) {
n if n < 0 => 512 as usize,
n => n as usize,
};
let mut buf = Vec::with_capacity(amt);
let mut p = mem::MaybeUninit::<libc::passwd>::uninit();
let mut result = ptr::null_mut();
match libc::getpwuid_r(
libc::getuid(),
p.as_mut_ptr(),
buf.as_mut_ptr(),
buf.capacity(),
&mut result,
) {
0 if !result.is_null() => {
let ptr = (*result).pw_dir as *const _;
let bytes = CStr::from_ptr(ptr).to_bytes().to_vec();
Some(OsStringExt::from_vec(bytes))
}
_ => None,
}
}
}
pub fn exit(code: i32) -> ! {
crate::sys::exit_guard::unique_thread_exit();
unsafe { libc::exit(code as c_int) }
}
pub fn getpid() -> u32 {
unsafe { libc::getpid() as u32 }
}
pub fn getppid() -> u32 {
unsafe { libc::getppid() as u32 }
}
#[cfg(all(target_os = "linux", target_env = "gnu"))]
pub fn glibc_version() -> Option<(usize, usize)> {
unsafe extern "C" {
fn gnu_get_libc_version() -> *const libc::c_char;
}
let version_cstr = unsafe { CStr::from_ptr(gnu_get_libc_version()) };
if let Ok(version_str) = version_cstr.to_str() {
parse_glibc_version(version_str)
} else {
None
}
}
// Returns Some((major, minor)) if the string is a valid "x.y" version,
// ignoring any extra dot-separated parts. Otherwise return None.
#[cfg(all(target_os = "linux", target_env = "gnu"))]
fn parse_glibc_version(version: &str) -> Option<(usize, usize)> {
let mut parsed_ints = version.split('.').map(str::parse::<usize>).fuse();
match (parsed_ints.next(), parsed_ints.next()) {
(Some(Ok(major)), Some(Ok(minor))) => Some((major, minor)),
_ => None,
}
}