| use crate::ffi::CString; |
| use crate::path::SMALL_PATH_BUFFER_SIZE; |
| use crate::{backend, io, path}; |
| use alloc::vec::Vec; |
| #[cfg(not(target_os = "fuchsia"))] |
| use backend::fd::AsFd; |
| |
| /// `chdir(path)`—Change the current working directory. |
| /// |
| /// # References |
| /// - [POSIX] |
| /// - [Linux] |
| /// |
| /// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/chdir.html |
| /// [Linux]: https://man7.org/linux/man-pages/man2/chdir.2.html |
| #[inline] |
| pub fn chdir<P: path::Arg>(path: P) -> io::Result<()> { |
| path.into_with_c_str(backend::process::syscalls::chdir) |
| } |
| |
| /// `fchdir(fd)`—Change the current working directory. |
| /// |
| /// # References |
| /// - [POSIX] |
| /// - [Linux] |
| /// |
| /// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/fchdir.html |
| /// [Linux]: https://man7.org/linux/man-pages/man2/fchdir.2.html |
| #[cfg(not(target_os = "fuchsia"))] |
| #[inline] |
| pub fn fchdir<Fd: AsFd>(fd: Fd) -> io::Result<()> { |
| backend::process::syscalls::fchdir(fd.as_fd()) |
| } |
| |
| /// `getcwd()`—Return the current working directory. |
| /// |
| /// If `reuse` is non-empty, reuse its buffer to store the result if possible. |
| /// |
| /// # References |
| /// - [POSIX] |
| /// - [Linux] |
| /// |
| /// [POSIX]: https://pubs.opengroup.org/onlinepubs/9699919799/functions/getcwd.html |
| /// [Linux]: https://man7.org/linux/man-pages/man3/getcwd.3.html |
| #[cfg(not(target_os = "wasi"))] |
| #[inline] |
| pub fn getcwd<B: Into<Vec<u8>>>(reuse: B) -> io::Result<CString> { |
| _getcwd(reuse.into()) |
| } |
| |
| fn _getcwd(mut buffer: Vec<u8>) -> io::Result<CString> { |
| // This code would benefit from having a better way to read into |
| // uninitialized memory, but that requires `unsafe`. |
| buffer.clear(); |
| buffer.reserve(SMALL_PATH_BUFFER_SIZE); |
| buffer.resize(buffer.capacity(), 0_u8); |
| |
| loop { |
| match backend::process::syscalls::getcwd(&mut buffer) { |
| Err(io::Errno::RANGE) => { |
| buffer.reserve(1); // use `Vec` reallocation strategy to grow capacity exponentially |
| buffer.resize(buffer.capacity(), 0_u8); |
| } |
| Ok(_) => { |
| let len = buffer.iter().position(|x| *x == b'\0').unwrap(); |
| buffer.resize(len, 0_u8); |
| return Ok(CString::new(buffer).unwrap()); |
| } |
| Err(errno) => return Err(errno), |
| } |
| } |
| } |