diff --git a/src/unistd.rs b/src/unistd.rs index d4da60da68..74d74c9c31 100644 --- a/src/unistd.rs +++ b/src/unistd.rs @@ -3,11 +3,14 @@ use {Errno, Error, Result, NixPath}; use fcntl::{fcntl, OFlag, O_NONBLOCK, O_CLOEXEC, FD_CLOEXEC}; use fcntl::FcntlArg::{F_SETFD, F_SETFL}; -use libc::{self, c_char, c_void, c_int, c_uint, size_t, pid_t, off_t, uid_t, gid_t}; +use libc::{self, c_char, c_void, c_int, c_uint, size_t, pid_t, off_t, uid_t, gid_t, mode_t}; use std::mem; -use std::ffi::CString; +use std::ffi::{CString, CStr, OsString}; +use std::os::unix::ffi::OsStringExt; +use std::path::PathBuf; use std::os::unix::io::RawFd; use void::Void; +use sys::stat::Mode; #[cfg(any(target_os = "linux", target_os = "android"))] pub use self::linux::*; @@ -111,6 +114,100 @@ pub fn chdir(path: &P) -> Result<()> { Errno::result(res).map(drop) } +/// Creates new directory `path` with access rights `mode`. +/// +/// # Errors +/// +/// There are several situations where mkdir might fail: +/// +/// - current user has insufficient rights in the parent directory +/// - the path already exists +/// - the path name is too long (longer than `PATH_MAX`, usually 4096 on linux, 1024 on OS X) +/// +/// For a full list consult +/// [man mkdir(2)](http://man7.org/linux/man-pages/man2/mkdir.2.html#ERRORS) +/// +/// # Example +/// +/// ```rust +/// extern crate tempdir; +/// extern crate nix; +/// +/// use nix::unistd; +/// use nix::sys::stat; +/// use tempdir::TempDir; +/// +/// fn main() { +/// let mut tmp_dir = TempDir::new("test_mkdir").unwrap().into_path(); +/// tmp_dir.push("new_dir"); +/// +/// // create new directory and give read, write and execute rights to the owner +/// match unistd::mkdir(&tmp_dir, stat::S_IRWXU) { +/// Ok(_) => println!("created {:?}", tmp_dir), +/// Err(err) => println!("Error creating directory: {}", err), +/// } +/// } +/// ``` +#[inline] +pub fn mkdir(path: &P, mode: Mode) -> Result<()> { + let res = try!(path.with_nix_path(|cstr| { + unsafe { libc::mkdir(cstr.as_ptr(), mode.bits() as mode_t) } + })); + + Errno::result(res).map(drop) +} + +/// Returns the current directory as a PathBuf +/// +/// Err is returned if the current user doesn't have the permission to read or search a component +/// of the current path. +/// +/// # Example +/// +/// ```rust +/// extern crate nix; +/// +/// use nix::unistd; +/// +/// fn main() { +/// // assume that we are allowed to get current directory +/// let dir = unistd::getcwd().unwrap(); +/// println!("The current directory is {:?}", dir); +/// } +/// ``` +#[inline] +pub fn getcwd() -> Result { + let mut buf = Vec::with_capacity(512); + loop { + unsafe { + let ptr = buf.as_mut_ptr() as *mut libc::c_char; + + // The buffer must be large enough to store the absolute pathname plus + // a terminating null byte, or else null is returned. + // To safely handle this we start with a reasonable size (512 bytes) + // and double the buffer size upon every error + 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 = Errno::last(); + // ERANGE means buffer was too small to store directory name + if error != Errno::ERANGE { + return Err(Error::Sys(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); + } + } +} + #[inline] pub fn chown(path: &P, owner: Option, group: Option) -> Result<()> { let res = try!(path.with_nix_path(|cstr| { diff --git a/test/test_unistd.rs b/test/test_unistd.rs index 188bfbeba9..f7bbe0bfca 100644 --- a/test/test_unistd.rs +++ b/test/test_unistd.rs @@ -1,38 +1,41 @@ +extern crate tempdir; + use nix::unistd::*; use nix::unistd::ForkResult::*; use nix::sys::wait::*; +use nix::sys::stat; +use std::iter; use std::ffi::CString; - use std::io::{Write, Read}; +use std::os::unix::prelude::*; +use std::env::current_dir; use tempfile::tempfile; +use tempdir::TempDir; use libc::off_t; -use std::os::unix::prelude::*; - - #[test] fn test_fork_and_waitpid() { let pid = fork(); match pid { - Ok(Child) => {} // ignore child here - Ok(Parent { child }) => { - // assert that child was created and pid > 0 - assert!(child > 0); - let wait_status = waitpid(child, None); - match wait_status { - // assert that waitpid returned correct status and the pid is the one of the child - Ok(WaitStatus::Exited(pid_t, _)) => assert!(pid_t == child), - - // panic, must never happen - Ok(_) => panic!("Child still alive, should never happen"), - - // panic, waitpid should never fail - Err(_) => panic!("Error: waitpid Failed") - } - - }, - // panic, fork should never fail unless there is a serious problem with the OS - Err(_) => panic!("Error: Fork Failed") + Ok(Child) => {} // ignore child here + Ok(Parent { child }) => { + // assert that child was created and pid > 0 + assert!(child > 0); + let wait_status = waitpid(child, None); + match wait_status { + // assert that waitpid returned correct status and the pid is the one of the child + Ok(WaitStatus::Exited(pid_t, _)) => assert!(pid_t == child), + + // panic, must never happen + Ok(_) => panic!("Child still alive, should never happen"), + + // panic, waitpid should never fail + Err(_) => panic!("Error: waitpid Failed") + } + + }, + // panic, fork should never fail unless there is a serious problem with the OS + Err(_) => panic!("Error: Fork Failed") } } @@ -40,15 +43,15 @@ fn test_fork_and_waitpid() { fn test_wait() { let pid = fork(); match pid { - Ok(Child) => {} // ignore child here - Ok(Parent { child }) => { - let wait_status = wait(); - - // just assert that (any) one child returns with WaitStatus::Exited - assert_eq!(wait_status, Ok(WaitStatus::Exited(child, 0))); - }, - // panic, fork should never fail unless there is a serious problem with the OS - Err(_) => panic!("Error: Fork Failed") + Ok(Child) => {} // ignore child here + Ok(Parent { child }) => { + let wait_status = wait(); + + // just assert that (any) one child returns with WaitStatus::Exited + assert_eq!(wait_status, Ok(WaitStatus::Exited(child, 0))); + }, + // panic, fork should never fail unless there is a serious problem with the OS + Err(_) => panic!("Error: Fork Failed") } } @@ -119,6 +122,24 @@ macro_rules! execve_test_factory( ) ); +#[test] +fn test_getcwd() { + let mut tmp_dir = TempDir::new("test_getcwd").unwrap().into_path(); + assert!(chdir(tmp_dir.as_path()).is_ok()); + assert_eq!(getcwd().unwrap(), current_dir().unwrap()); + + // make path 500 chars longer so that buffer doubling in getcwd kicks in. + // Note: One path cannot be longer than 255 bytes (NAME_MAX) + // whole path cannot be longer than PATH_MAX (usually 4096 on linux, 1024 on macos) + for _ in 0..5 { + let newdir = iter::repeat("a").take(100).collect::(); + tmp_dir.push(newdir); + assert!(mkdir(tmp_dir.as_path(), stat::S_IRWXU).is_ok()); + } + assert!(chdir(tmp_dir.as_path()).is_ok()); + assert_eq!(getcwd().unwrap(), current_dir().unwrap()); +} + #[test] fn test_lseek() { const CONTENTS: &'static [u8] = b"abcdef123456"; @@ -129,10 +150,10 @@ fn test_lseek() { lseek(tmp.as_raw_fd(), offset, Whence::SeekSet).unwrap(); let mut buf = String::new(); - tmp.read_to_string(&mut buf).unwrap(); - assert_eq!(b"f123456", buf.as_bytes()); + tmp.read_to_string(&mut buf).unwrap(); + assert_eq!(b"f123456", buf.as_bytes()); - close(tmp.as_raw_fd()).unwrap(); + close(tmp.as_raw_fd()).unwrap(); } #[cfg(any(target_os = "linux", target_os = "android"))]