std::ffi::OsString

Struct std::ffi::OsString

pub struct OsString { /* fields omitted */ }

A type that can represent owned, mutable platform-native strings, but is cheaply inter-convertible with Rust strings.

The need for this type arises from the fact that:

  • On Unix systems, strings are often arbitrary sequences of non-zero bytes, in many cases interpreted as UTF-8.

  • On Windows, strings are often arbitrary sequences of non-zero 16-bit values, interpreted as UTF-16 when it is valid to do so.

  • In Rust, strings are always valid UTF-8, but may contain zeros.

OsString and OsStr bridge this gap by simultaneously representing Rust and platform-native string values, and in particular allowing a Rust string to be converted into an "OS" string with no cost.

Methods

impl OsString [src]

Constructs a new empty OsString.

Examples

use std::ffi::OsString;

let os_string = OsString::new();

Converts to an OsStr slice.

Examples

use std::ffi::{OsString, OsStr};

let os_string = OsString::from("foo");
let os_str = OsStr::new("foo");
assert_eq!(os_string.as_os_str(), os_str);

Converts the OsString into a String if it contains valid Unicode data.

On failure, ownership of the original OsString is returned.

Examples

use std::ffi::OsString;

let os_string = OsString::from("foo");
let string = os_string.into_string();
assert_eq!(string, Ok(String::from("foo")));

Extends the string with the given &OsStr slice.

Examples

use std::ffi::OsString;

let mut os_string = OsString::from("foo");
os_string.push("bar");
assert_eq!(&os_string, "foobar");

Creates a new OsString with the given capacity.

The string will be able to hold exactly capacity lenth units of other OS strings without reallocating. If capacity is 0, the string will not allocate.

See main OsString documentation information about encoding.

Examples

use std::ffi::OsString;

let mut os_string = OsString::with_capacity(10);
let capacity = os_string.capacity();

// This push is done without reallocating
os_string.push("foo");

assert_eq!(capacity, os_string.capacity());

Truncates the OsString to zero length.

Examples

use std::ffi::OsString;

let mut os_string = OsString::from("foo");
assert_eq!(&os_string, "foo");

os_string.clear();
assert_eq!(&os_string, "");

Returns the capacity this OsString can hold without reallocating.

See OsString introduction for information about encoding.

Examples

use std::ffi::OsString;

let mut os_string = OsString::with_capacity(10);
assert!(os_string.capacity() >= 10);

Reserves capacity for at least additional more capacity to be inserted in the given OsString.

The collection may reserve more space to avoid frequent reallocations.

Examples

use std::ffi::OsString;

let mut s = OsString::new();
s.reserve(10);
assert!(s.capacity() >= 10);

Reserves the minimum capacity for exactly additional more capacity to be inserted in the given OsString. Does nothing if the capacity is already sufficient.

Note that the allocator may give the collection more space than it requests. Therefore capacity can not be relied upon to be precisely minimal. Prefer reserve if future insertions are expected.

Examples

use std::ffi::OsString;

let mut s = OsString::new();
s.reserve_exact(10);
assert!(s.capacity() >= 10);

???? This is a nightly-only experimental API. (osstring_shrink_to_fit #40421)

Shrinks the capacity of the OsString to match its length.

Examples

#![feature(osstring_shrink_to_fit)]

use std::ffi::OsString;

let mut s = OsString::from("foo");

s.reserve(100);
assert!(s.capacity() >= 100);

s.shrink_to_fit();
assert_eq!(3, s.capacity());

???? This is a nightly-only experimental API. (into_boxed_os_str #40380)

Converts this OsString into a boxed OsStr.

Examples

#![feature(into_boxed_os_str)]

use std::ffi::{OsString, OsStr};

let s = OsString::from("hello");

let b: Box<OsStr> = s.into_boxed_os_str();

Methods from Deref<Target = OsStr>

Yields a &str slice if the OsStr is valid Unicode.

This conversion may entail doing a check for UTF-8 validity.

Examples

use std::ffi::OsStr;

let os_str = OsStr::new("foo");
assert_eq!(os_str.to_str(), Some("foo"));

Converts an OsStr to a Cow<str>.

Any non-Unicode sequences are replaced with U+FFFD REPLACEMENT CHARACTER.

Examples

Calling to_string_lossy on an OsStr with valid unicode:

use std::ffi::OsStr;

let os_str = OsStr::new("foo");
assert_eq!(os_str.to_string_lossy(), "foo");

Had os_str contained invalid unicode, the to_string_lossy call might have returned "fo�".

Copies the slice into an owned OsString.

Examples

use std::ffi::{OsStr, OsString};

let os_str = OsStr::new("foo");
let os_string = os_str.to_os_string();
assert_eq!(os_string, OsString::from("foo"));

Checks whether the OsStr is empty.

Examples

use std::ffi::OsStr;

let os_str = OsStr::new("");
assert!(os_str.is_empty());

let os_str = OsStr::new("foo");
assert!(!os_str.is_empty());

Returns the length of this OsStr.

Note that this does not return the number of bytes in this string as, for example, OS strings on Windows are encoded as a list of u16 rather than a list of bytes. This number is simply useful for passing to other methods like OsString::with_capacity to avoid reallocations.

See OsStr introduction for more information about encoding.

Examples

use std::ffi::OsStr;

let os_str = OsStr::new("");
assert_eq!(os_str.len(), 0);

let os_str = OsStr::new("foo");
assert_eq!(os_str.len(), 3);

???? This is a nightly-only experimental API. (into_boxed_os_str #40380)

Converts a Box<OsStr> into an OsString without copying or allocating.

Trait Implementations

impl Clone for OsString [src]

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

impl From<String> for OsString [src]

Performs the conversion.

impl<'a, T: ?Sized + AsRef<OsStr>> From<&'a T> for OsString [src]

Performs the conversion.

impl Index<RangeFull> for OsString [src]

The returned type after indexing

The method for the indexing (container[index]) operation

impl Deref for OsString [src]

The resulting type after dereferencing

The method called to dereference a value

impl Default for OsString
1.9.0
[src]

Constructs an empty OsString.

impl Debug for OsString [src]

Formats the value using the given formatter.

impl PartialEq for OsString [src]

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

impl PartialEq<str> for OsString [src]

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

impl Eq for OsString [src]

impl PartialOrd for OsString [src]

This method returns an ordering between self and other values if one exists. Read more

This method tests less than (for self and other) and is used by the < operator. Read more

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more

This method tests greater than (for self and other) and is used by the > operator. Read more

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

impl PartialOrd<str> for OsString [src]

This method returns an ordering between self and other values if one exists. Read more

This method tests less than (for self and other) and is used by the < operator. Read more

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more

This method tests greater than (for self and other) and is used by the > operator. Read more

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

impl Ord for OsString [src]

This method returns an Ordering between self and other. Read more

impl Hash for OsString [src]

Feeds this value into the given [Hasher]. Read more

Feeds a slice of this type into the given [Hasher]. Read more

impl<'a> From<Box<OsStr>> for OsString
1.17.0
[src]

Performs the conversion.

impl Into<Box<OsStr>> for OsString
1.17.0
[src]

Performs the conversion.

impl<'a, 'b> PartialEq<OsStr> for OsString
1.8.0
[src]

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

impl<'a, 'b> PartialOrd<OsStr> for OsString
1.8.0
[src]

This method returns an ordering between self and other values if one exists. Read more

This method tests less than (for self and other) and is used by the < operator. Read more

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more

This method tests greater than (for self and other) and is used by the > operator. Read more

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

impl<'a, 'b> PartialEq<&'a OsStr> for OsString
1.8.0
[src]

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

impl<'a, 'b> PartialOrd<&'a OsStr> for OsString
1.8.0
[src]

This method returns an ordering between self and other values if one exists. Read more

This method tests less than (for self and other) and is used by the < operator. Read more

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more

This method tests greater than (for self and other) and is used by the > operator. Read more

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

impl<'a, 'b> PartialEq<Cow<'a, OsStr>> for OsString
1.8.0
[src]

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

impl<'a, 'b> PartialOrd<Cow<'a, OsStr>> for OsString
1.8.0
[src]

This method returns an ordering between self and other values if one exists. Read more

This method tests less than (for self and other) and is used by the < operator. Read more

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more

This method tests greater than (for self and other) and is used by the > operator. Read more

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

impl Borrow<OsStr> for OsString [src]

Immutably borrows from an owned value. Read more

impl AsRef<OsStr> for OsString [src]

Performs the conversion.

impl From<PathBuf> for OsString
1.14.0
[src]

Performs the conversion.

impl AsRef<Path> for OsString [src]

Performs the conversion.

impl<'a, 'b> PartialEq<PathBuf> for OsString
1.8.0
[src]

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

impl<'a, 'b> PartialOrd<PathBuf> for OsString
1.8.0
[src]

This method returns an ordering between self and other values if one exists. Read more

This method tests less than (for self and other) and is used by the < operator. Read more

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more

This method tests greater than (for self and other) and is used by the > operator. Read more

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

impl<'a, 'b> PartialEq<Path> for OsString
1.8.0
[src]

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

impl<'a, 'b> PartialOrd<Path> for OsString
1.8.0
[src]

This method returns an ordering between self and other values if one exists. Read more

This method tests less than (for self and other) and is used by the < operator. Read more

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more

This method tests greater than (for self and other) and is used by the > operator. Read more

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

impl<'a, 'b> PartialEq<&'a Path> for OsString
1.8.0
[src]

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

impl<'a, 'b> PartialOrd<&'a Path> for OsString
1.8.0
[src]

This method returns an ordering between self and other values if one exists. Read more

This method tests less than (for self and other) and is used by the < operator. Read more

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more

This method tests greater than (for self and other) and is used by the > operator. Read more

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

impl<'a, 'b> PartialEq<Cow<'a, Path>> for OsString
1.8.0
[src]

This method tests for self and other values to be equal, and is used by ==. Read more

This method tests for !=.

impl<'a, 'b> PartialOrd<Cow<'a, Path>> for OsString
1.8.0
[src]

This method returns an ordering between self and other values if one exists. Read more

This method tests less than (for self and other) and is used by the < operator. Read more

This method tests less than or equal to (for self and other) and is used by the <= operator. Read more

This method tests greater than (for self and other) and is used by the > operator. Read more

This method tests greater than or equal to (for self and other) and is used by the >= operator. Read more

impl OsStringExt for OsString [src]

Creates an [OsString] from a byte vector. Read more

Yields the underlying byte vector of this [OsString]. Read more

© 2010 The Rust Project Developers
Licensed under the Apache License, Version 2.0 or the MIT license, at your option.
https://doc.rust-lang.org/std/ffi/struct.OsString.html

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