| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you under the Apache License, Version 2.0 (the |
| // "License"); you may not use this file except in compliance |
| // with the License. You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, |
| // software distributed under the License is distributed on an |
| // "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| // KIND, either express or implied. See the License for the |
| // specific language governing permissions and limitations |
| // under the License.. |
| |
| //! Inspection and manipulation of the process's environment. |
| |
| use core::fmt; |
| use crate::error::Error; |
| use crate::ffi::{OsStr, OsString}; |
| use crate::path::{Path, PathBuf}; |
| use crate::sys::os as os_imp; |
| use crate::io; |
| |
| /// Returns the current working directory as a [`PathBuf`]. |
| /// |
| /// # Errors |
| /// |
| /// Returns an [`Err`] if the current working directory value is invalid. |
| /// Possible cases: |
| /// |
| /// * Current directory does not exist. |
| /// * There are insufficient permissions to access the current directory. |
| /// |
| /// [`PathBuf`]: ../../std/path/struct.PathBuf.html |
| /// [`Err`]: ../../std/result/enum.Result.html#method.err |
| /// |
| pub fn current_dir() -> io::Result<PathBuf> { |
| os_imp::getcwd() |
| } |
| |
| /// Changes the current working directory to the specified path. |
| /// |
| /// Returns an [`Err`] if the operation fails. |
| /// |
| /// [`Err`]: ../../std/result/enum.Result.html#method.err |
| /// |
| pub fn set_current_dir<P: AsRef<Path>>(path: P) -> io::Result<()> { |
| os_imp::chdir(path.as_ref()) |
| } |
| |
| /// An iterator over a snapshot of the environment variables of this process. |
| /// |
| /// This structure is created by the [`std::env::vars`] function. See its |
| /// documentation for more. |
| /// |
| /// [`std::env::vars`]: fn.vars.html |
| pub struct Vars { |
| inner: VarsOs, |
| } |
| |
| /// An iterator over a snapshot of the environment variables of this process. |
| /// |
| /// This structure is created by the [`std::env::vars_os`] function. See |
| /// its documentation for more. |
| /// |
| /// [`std::env::vars_os`]: fn.vars_os.html |
| pub struct VarsOs { |
| inner: os_imp::Env, |
| } |
| |
| /// Returns an iterator of (variable, value) pairs of strings, for all the |
| /// environment variables of the current process. |
| /// |
| /// The returned iterator contains a snapshot of the process's environment |
| /// variables at the time of this invocation. Modifications to environment |
| /// variables afterwards will not be reflected in the returned iterator. |
| /// |
| /// # Panics |
| /// |
| /// While iterating, the returned iterator will panic if any key or value in the |
| /// environment is not valid unicode. If this is not desired, consider using the |
| /// [`env::vars_os`] function. |
| /// |
| /// [`env::vars_os`]: fn.vars_os.html |
| pub fn vars() -> Vars { |
| Vars { inner: vars_os() } |
| } |
| |
| /// Returns an iterator of (variable, value) pairs of OS strings, for all the |
| /// environment variables of the current process. |
| /// |
| /// The returned iterator contains a snapshot of the process's environment |
| /// variables at the time of this invocation. Modifications to environment |
| /// variables afterwards will not be reflected in the returned iterator. |
| /// |
| pub fn vars_os() -> VarsOs { |
| VarsOs { inner: os_imp::env() } |
| } |
| |
| impl Iterator for Vars { |
| type Item = (String, String); |
| fn next(&mut self) -> Option<(String, String)> { |
| self.inner.next().map(|(a, b)| (a.into_string().unwrap(), b.into_string().unwrap())) |
| } |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| self.inner.size_hint() |
| } |
| } |
| |
| impl fmt::Debug for Vars { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| f.pad("Vars { .. }") |
| } |
| } |
| |
| impl Iterator for VarsOs { |
| type Item = (OsString, OsString); |
| fn next(&mut self) -> Option<(OsString, OsString)> { |
| self.inner.next() |
| } |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| self.inner.size_hint() |
| } |
| } |
| |
| impl fmt::Debug for VarsOs { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| f.pad("VarsOs { .. }") |
| } |
| } |
| |
| /// Fetches the environment variable `key` from the current process. |
| /// |
| /// # Errors |
| /// |
| /// * Environment variable is not present |
| /// * Environment variable is not valid unicode |
| /// |
| /// # Panics |
| /// |
| /// This function may panic if `key` is empty, contains an ASCII equals sign |
| /// `'='` or the NUL character `'\0'`, or when the value contains the NUL |
| /// character. |
| /// |
| pub fn var<K: AsRef<OsStr>>(key: K) -> Result<String, VarError> { |
| _var(key.as_ref()) |
| } |
| |
| fn _var(key: &OsStr) -> Result<String, VarError> { |
| match var_os(key) { |
| Some(s) => s.into_string().map_err(VarError::NotUnicode), |
| None => Err(VarError::NotPresent), |
| } |
| } |
| |
| /// Fetches the environment variable `key` from the current process, returning |
| /// [`None`] if the variable isn't set. |
| /// |
| /// [`None`]: ../option/enum.Option.html#variant.None |
| /// |
| /// # Panics |
| /// |
| /// This function may panic if `key` is empty, contains an ASCII equals sign |
| /// `'='` or the NUL character `'\0'`, or when the value contains the NUL |
| /// character. |
| /// |
| pub fn var_os<K: AsRef<OsStr>>(key: K) -> Option<OsString> { |
| _var_os(key.as_ref()) |
| } |
| |
| fn _var_os(key: &OsStr) -> Option<OsString> { |
| os_imp::getenv(key) |
| .unwrap_or_else(|e| panic!("failed to get environment variable `{:?}`: {}", key, e)) |
| } |
| |
| /// The error type for operations interacting with environment variables. |
| /// Possibly returned from the [`env::var`] function. |
| /// |
| /// [`env::var`]: fn.var.html |
| #[derive(Debug, PartialEq, Eq, Clone)] |
| pub enum VarError { |
| /// The specified environment variable was not present in the current |
| /// process's environment. |
| NotPresent, |
| |
| /// The specified environment variable was found, but it did not contain |
| /// valid unicode data. The found data is returned as a payload of this |
| /// variant. |
| NotUnicode(OsString), |
| } |
| |
| impl fmt::Display for VarError { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| match *self { |
| VarError::NotPresent => write!(f, "environment variable not found"), |
| VarError::NotUnicode(ref s) => { |
| write!(f, "environment variable was not valid unicode: {:?}", s) |
| } |
| } |
| } |
| } |
| |
| impl Error for VarError { |
| fn description(&self) -> &str { |
| match *self { |
| VarError::NotPresent => "environment variable not found", |
| VarError::NotUnicode(..) => "environment variable was not valid unicode", |
| } |
| } |
| } |
| |
| /// Sets the environment variable `k` to the value `v` for the currently running |
| /// process. |
| /// |
| /// Note that while concurrent access to environment variables is safe in Rust, |
| /// some platforms only expose inherently unsafe non-threadsafe APIs for |
| /// inspecting the environment. As a result, extra care needs to be taken when |
| /// auditing calls to unsafe external FFI functions to ensure that any external |
| /// environment accesses are properly synchronized with accesses in Rust. |
| /// |
| /// Discussion of this unsafety on Unix may be found in: |
| /// |
| /// - [Austin Group Bugzilla](http://austingroupbugs.net/view.php?id=188) |
| /// - [GNU C library Bugzilla](https://sourceware.org/bugzilla/show_bug.cgi?id=15607#c2) |
| /// |
| /// # Panics |
| /// |
| /// This function may panic if `key` is empty, contains an ASCII equals sign |
| /// `'='` or the NUL character `'\0'`, or when the value contains the NUL |
| /// character. |
| /// |
| pub fn set_var<K: AsRef<OsStr>, V: AsRef<OsStr>>(k: K, v: V) { |
| _set_var(k.as_ref(), v.as_ref()) |
| } |
| |
| fn _set_var(k: &OsStr, v: &OsStr) { |
| os_imp::setenv(k, v).unwrap_or_else(|e| { |
| panic!("failed to set environment variable `{:?}` to `{:?}`: {}", k, v, e) |
| }) |
| } |
| |
| /// Removes an environment variable from the environment of the currently running process. |
| /// |
| /// Note that while concurrent access to environment variables is safe in Rust, |
| /// some platforms only expose inherently unsafe non-threadsafe APIs for |
| /// inspecting the environment. As a result extra care needs to be taken when |
| /// auditing calls to unsafe external FFI functions to ensure that any external |
| /// environment accesses are properly synchronized with accesses in Rust. |
| /// |
| /// Discussion of this unsafety on Unix may be found in: |
| /// |
| /// - [Austin Group Bugzilla](http://austingroupbugs.net/view.php?id=188) |
| /// - [GNU C library Bugzilla](https://sourceware.org/bugzilla/show_bug.cgi?id=15607#c2) |
| /// |
| /// # Panics |
| /// |
| /// This function may panic if `key` is empty, contains an ASCII equals sign |
| /// `'='` or the NUL character `'\0'`, or when the value contains the NUL |
| /// character. |
| /// |
| pub fn remove_var<K: AsRef<OsStr>>(k: K) { |
| _remove_var(k.as_ref()) |
| } |
| |
| fn _remove_var(k: &OsStr) { |
| os_imp::unsetenv(k) |
| .unwrap_or_else(|e| panic!("failed to remove environment variable `{:?}`: {}", k, e)) |
| } |
| |
| /// An iterator that splits an environment variable into paths according to |
| /// platform-specific conventions. |
| /// |
| /// The iterator element type is [`PathBuf`]. |
| /// |
| /// This structure is created by the [`std::env::split_paths`] function. See its |
| /// documentation for more. |
| /// |
| /// [`PathBuf`]: ../../std/path/struct.PathBuf.html |
| /// [`std::env::split_paths`]: fn.split_paths.html |
| pub struct SplitPaths<'a> { |
| inner: os_imp::SplitPaths<'a>, |
| } |
| |
| /// Parses input according to platform conventions for the `PATH` |
| /// environment variable. |
| /// |
| /// Returns an iterator over the paths contained in `unparsed`. The iterator |
| /// element type is [`PathBuf`]. |
| /// |
| pub fn split_paths<T: AsRef<OsStr> + ?Sized>(unparsed: &T) -> SplitPaths<'_> { |
| SplitPaths { inner: os_imp::split_paths(unparsed.as_ref()) } |
| } |
| |
| impl<'a> Iterator for SplitPaths<'a> { |
| type Item = PathBuf; |
| fn next(&mut self) -> Option<PathBuf> { |
| self.inner.next() |
| } |
| fn size_hint(&self) -> (usize, Option<usize>) { |
| self.inner.size_hint() |
| } |
| } |
| |
| impl fmt::Debug for SplitPaths<'_> { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| f.pad("SplitPaths { .. }") |
| } |
| } |
| |
| /// The error type for operations on the `PATH` variable. Possibly returned from |
| /// the [`env::join_paths`] function. |
| /// |
| /// [`env::join_paths`]: fn.join_paths.html |
| #[derive(Debug)] |
| pub struct JoinPathsError { |
| inner: os_imp::JoinPathsError, |
| } |
| |
| /// Joins a collection of [`Path`]s appropriately for the `PATH` |
| /// environment variable. |
| /// |
| /// # Errors |
| /// |
| /// Returns an [`Err`][err] (containing an error message) if one of the input |
| /// [`Path`]s contains an invalid character for constructing the `PATH` |
| /// variable (a double quote on Windows or a colon on Unix). |
| /// |
| /// [`Path`]: ../../std/path/struct.Path.html |
| /// [`OsString`]: ../../std/ffi/struct.OsString.html |
| /// [err]: ../../std/result/enum.Result.html#variant.Err |
| /// |
| pub fn join_paths<I, T>(paths: I) -> Result<OsString, JoinPathsError> |
| where |
| I: IntoIterator<Item = T>, |
| T: AsRef<OsStr>, |
| { |
| os_imp::join_paths(paths.into_iter()).map_err(|e| JoinPathsError { inner: e }) |
| } |
| |
| impl fmt::Display for JoinPathsError { |
| fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { |
| self.inner.fmt(f) |
| } |
| } |
| |
| impl Error for JoinPathsError { |
| fn description(&self) -> &str { |
| self.inner.description() |
| } |
| } |
| |
| /// Returns the path of the current user's home directory if known. |
| /// |
| /// # Unix |
| /// |
| /// - Returns the value of the 'HOME' environment variable if it is set |
| /// (including to an empty string). |
| /// - Otherwise, it tries to determine the home directory by invoking the `getpwuid_r` function |
| /// using the UID of the current user. An empty home directory field returned from the |
| /// `getpwuid_r` function is considered to be a valid value. |
| /// - Returns `None` if the current user has no entry in the /etc/passwd file. |
| /// |
| /// # Windows |
| /// |
| /// - Returns the value of the 'HOME' environment variable if it is set |
| /// (including to an empty string). |
| /// - Otherwise, returns the value of the 'USERPROFILE' environment variable if it is set |
| /// (including to an empty string). |
| /// - If both do not exist, [`GetUserProfileDirectory`][msdn] is used to return the path. |
| /// |
| /// [msdn]: https://docs.microsoft.com/en-us/windows/win32/api/userenv/nf-userenv-getuserprofiledirectorya |
| /// |
| pub fn home_dir() -> Option<PathBuf> { |
| os_imp::home_dir() |
| } |
| |
| /// Returns the path of a temporary directory. |
| /// |
| /// # Unix |
| /// |
| /// Returns the value of the `TMPDIR` environment variable if it is |
| /// set, otherwise for non-Android it returns `/tmp`. If Android, since there |
| /// is no global temporary folder (it is usually allocated per-app), it returns |
| /// `/data/local/tmp`. |
| /// |
| /// # Windows |
| /// |
| /// Returns the value of, in order, the `TMP`, `TEMP`, |
| /// `USERPROFILE` environment variable if any are set and not the empty |
| /// string. Otherwise, `temp_dir` returns the path of the Windows directory. |
| /// This behavior is identical to that of [`GetTempPath`][msdn], which this |
| /// function uses internally. |
| /// |
| /// [msdn]: https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-gettemppatha |
| /// |
| pub fn temp_dir() -> PathBuf { |
| os_imp::temp_dir() |
| } |
| |
| /// Returns the full filesystem path of the current running executable. |
| /// |
| /// # Platform-specific behavior |
| /// |
| /// If the executable was invoked through a symbolic link, some platforms will |
| /// return the path of the symbolic link and other platforms will return the |
| /// path of the symbolic link’s target. |
| /// |
| /// # Errors |
| /// |
| /// Acquiring the path of the current executable is a platform-specific operation |
| /// that can fail for a good number of reasons. Some errors can include, but not |
| /// be limited to, filesystem operations failing or general syscall failures. |
| /// |
| /// # Security |
| /// |
| /// The output of this function should not be used in anything that might have |
| /// security implications. For example: |
| /// |
| /// ``` |
| /// fn main() { |
| /// println!("{:?}", std::env::current_exe()); |
| /// } |
| /// ``` |
| /// |
| /// On Linux systems, if this is compiled as `foo`: |
| /// |
| /// ```bash |
| /// $ rustc foo.rs |
| /// $ ./foo |
| /// Ok("/home/alex/foo") |
| /// ``` |
| /// |
| /// And you make a hard link of the program: |
| /// |
| /// ```bash |
| /// $ ln foo bar |
| /// ``` |
| /// |
| /// When you run it, you won’t get the path of the original executable, you’ll |
| /// get the path of the hard link: |
| /// |
| /// ```bash |
| /// $ ./bar |
| /// Ok("/home/alex/bar") |
| /// ``` |
| /// |
| /// This sort of behavior has been known to [lead to privilege escalation] when |
| /// used incorrectly. |
| /// |
| /// [lead to privilege escalation]: https://securityvulns.com/Wdocument183.html |
| /// |
| pub fn current_exe() -> io::Result<PathBuf> { |
| os_imp::current_exe() |
| } |
| |
| /// Constants associated with the current target |
| pub mod consts { |
| use crate::sys::env::os; |
| |
| /// A string describing the architecture of the CPU that is currently |
| /// in use. |
| /// |
| /// Some possible values: |
| /// |
| /// - x86 |
| /// - x86_64 |
| /// - arm |
| /// - aarch64 |
| /// - mips |
| /// - mips64 |
| /// - powerpc |
| /// - powerpc64 |
| /// - riscv64 |
| /// - s390x |
| /// - sparc64 |
| pub const ARCH: &str = super::arch::ARCH; |
| |
| /// The family of the operating system. Example value is `unix`. |
| /// |
| /// Some possible values: |
| /// |
| /// - unix |
| /// - windows |
| pub const FAMILY: &str = os::FAMILY; |
| |
| /// A string describing the specific operating system in use. |
| /// Example value is `linux`. |
| /// |
| /// Some possible values: |
| /// |
| /// - linux |
| /// - macos |
| /// - ios |
| /// - freebsd |
| /// - dragonfly |
| /// - netbsd |
| /// - openbsd |
| /// - solaris |
| /// - android |
| /// - windows |
| pub const OS: &str = os::OS; |
| |
| /// Specifies the filename prefix used for shared libraries on this |
| /// platform. Example value is `lib`. |
| /// |
| /// Some possible values: |
| /// |
| /// - lib |
| /// - `""` (an empty string) |
| pub const DLL_PREFIX: &str = os::DLL_PREFIX; |
| |
| /// Specifies the filename suffix used for shared libraries on this |
| /// platform. Example value is `.so`. |
| /// |
| /// Some possible values: |
| /// |
| /// - .so |
| /// - .dylib |
| /// - .dll |
| pub const DLL_SUFFIX: &str = os::DLL_SUFFIX; |
| |
| /// Specifies the file extension used for shared libraries on this |
| /// platform that goes after the dot. Example value is `so`. |
| /// |
| /// Some possible values: |
| /// |
| /// - so |
| /// - dylib |
| /// - dll |
| pub const DLL_EXTENSION: &str = os::DLL_EXTENSION; |
| |
| /// Specifies the filename suffix used for executable binaries on this |
| /// platform. Example value is `.exe`. |
| /// |
| /// Some possible values: |
| /// |
| /// - .exe |
| /// - .nexe |
| /// - .pexe |
| /// - `""` (an empty string) |
| pub const EXE_SUFFIX: &str = os::EXE_SUFFIX; |
| |
| /// Specifies the file extension, if any, used for executable binaries |
| /// on this platform. Example value is `exe`. |
| /// |
| /// Some possible values: |
| /// |
| /// - exe |
| /// - `""` (an empty string) |
| pub const EXE_EXTENSION: &str = os::EXE_EXTENSION; |
| } |
| |
| #[cfg(target_arch = "x86")] |
| mod arch { |
| pub const ARCH: &str = "x86"; |
| } |
| |
| #[cfg(target_arch = "x86_64")] |
| mod arch { |
| pub const ARCH: &str = "x86_64"; |
| } |