[−][src]Trait tokio::fs::os::windows::OpenOptionsExt
fs only.Unix-specific extensions to fs::OpenOptions.
This mirrors the definition of std::os::windows::fs::OpenOptionsExt.
Required methods
fn access_mode(&mut self, access: u32) -> &mut Selfⓘ
Overrides the dwDesiredAccess argument to the call to CreateFile
with the specified value.
This will override the read, write, and append flags on the
OpenOptions structure. This method provides fine-grained control over
the permissions to read, write and append data, attributes (like hidden
and system), and extended attributes.
Examples
use tokio::fs::OpenOptions; use tokio::fs::os::windows::OpenOptionsExt; // Open without read and write permission, for example if you only need // to call `stat` on the file let file = OpenOptions::new().access_mode(0).open("foo.txt").await?;
fn share_mode(&mut self, val: u32) -> &mut Selfⓘ
Overrides the dwShareMode argument to the call to CreateFile with
the specified value.
By default share_mode is set to
FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE. This allows
other processes to read, write, and delete/rename the same file
while it is open. Removing any of the flags will prevent other
processes from performing the corresponding operation until the file
handle is closed.
Examples
use tokio::fs::OpenOptions; use tokio::fs::os::windows::OpenOptionsExt; // Do not allow others to read or modify this file while we have it open // for writing. let file = OpenOptions::new() .write(true) .share_mode(0) .open("foo.txt").await?;
fn custom_flags(&mut self, flags: u32) -> &mut Selfⓘ
Sets extra flags for the dwFileFlags argument to the call to
CreateFile2 to the specified value (or combines it with
attributes and security_qos_flags to set the dwFlagsAndAttributes
for CreateFile).
Custom flags can only set flags, not remove flags set by Rust's options. This option overwrites any previously set custom flags.
Examples
use winapi::um::winbase::FILE_FLAG_DELETE_ON_CLOSE; use tokio::fs::OpenOptions; use tokio::fs::os::windows::OpenOptionsExt; let file = OpenOptions::new() .create(true) .write(true) .custom_flags(FILE_FLAG_DELETE_ON_CLOSE) .open("foo.txt").await?;
fn attributes(&mut self, val: u32) -> &mut Selfⓘ
Sets the dwFileAttributes argument to the call to CreateFile2 to
the specified value (or combines it with custom_flags and
security_qos_flags to set the dwFlagsAndAttributes for
CreateFile).
If a new file is created because it does not yet exist and
.create(true) or .create_new(true) are specified, the new file is
given the attributes declared with .attributes().
If an existing file is opened with .create(true).truncate(true), its
existing attributes are preserved and combined with the ones declared
with .attributes().
In all other cases the attributes get ignored.
Examples
use winapi::um::winnt::FILE_ATTRIBUTE_HIDDEN; use tokio::fs::OpenOptions; use tokio::fs::os::windows::OpenOptionsExt; let file = OpenOptions::new() .write(true) .create(true) .attributes(FILE_ATTRIBUTE_HIDDEN) .open("foo.txt").await?;
fn security_qos_flags(&mut self, flags: u32) -> &mut Selfⓘ
Sets the dwSecurityQosFlags argument to the call to CreateFile2 to
the specified value (or combines it with custom_flags and attributes
to set the dwFlagsAndAttributes for CreateFile).
By default security_qos_flags is not set. It should be specified when
opening a named pipe, to control to which degree a server process can
act on behalf of a client process (security impersonation level).
When security_qos_flags is not set, a malicious program can gain the
elevated privileges of a privileged Rust process when it allows opening
user-specified paths, by tricking it into opening a named pipe. So
arguably security_qos_flags should also be set when opening arbitrary
paths. However the bits can then conflict with other flags, specifically
FILE_FLAG_OPEN_NO_RECALL.
For information about possible values, see Impersonation Levels on the
Windows Dev Center site. The SECURITY_SQOS_PRESENT flag is set
automatically when using this method.
Examples
use winapi::um::winbase::SECURITY_IDENTIFICATION; use tokio::fs::OpenOptions; use tokio::fs::os::windows::OpenOptionsExt; let file = OpenOptions::new() .write(true) .create(true) // Sets the flag value to `SecurityIdentification`. .security_qos_flags(SECURITY_IDENTIFICATION) .open(r"\\.\pipe\MyPipe").await?;