pub trait OpenOptionsExt {
// Required methods
fn access_mode(&mut self, access: u32) -> &mut Self;
fn share_mode(&mut self, val: u32) -> &mut Self;
fn custom_flags(&mut self, flags: u32) -> &mut Self;
fn attributes(&mut self, val: u32) -> &mut Self;
fn security_qos_flags(&mut self, flags: u32) -> &mut Self;
}Expand description
Windows-specific extensions to fs::OpenOptions.
Required Methods§
1.10.0 · Sourcefn access_mode(&mut self, access: u32) -> &mut Self
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
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
1.10.0 · Sourcefn custom_flags(&mut self, flags: u32) -> &mut Self
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
1.10.0 · Sourcefn attributes(&mut self, val: u32) -> &mut Self
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
1.10.0 · Sourcefn security_qos_flags(&mut self, flags: u32) -> &mut Self
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
Dyn Compatibility§
This trait is not dyn compatible.
In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.