Struct OsArgument

#[repr(transparent)]
pub struct OsArgument(pub OsStr);

A newtype wrapper around OsStr that allows it to be parsed by Options.

The short option type for this Argument implementation is UTF-8 codepoints; however they may not all be valid chars.

Tuple Fields

0: OsStr

Methods from Deref<Target = OsStr>

pub fn to_str(&self) -> Option<&str>

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"));

pub fn to_string_lossy(&self) -> Cow<'_, str>

Converts an OsStr to a Cow<str>.

Any non-UTF-8 sequences are replaced with U+FFFD REPLACEMENT CHARACTER.

Examples

Calling to_string_lossy on an OsStr with invalid unicode:

// Note, due to differences in how Unix and Windows represent strings,
// we are forced to complicate this example, setting up example `OsStr`s
// with different source data and via different platform extensions.
// Understand that in reality you could end up with such example invalid
// sequences simply through collecting user command line arguments, for
// example.

#[cfg(unix)] {
    use std::ffi::OsStr;
    use std::os::unix::ffi::OsStrExt;

    // Here, the values 0x66 and 0x6f correspond to 'f' and 'o'
    // respectively. The value 0x80 is a lone continuation byte, invalid
    // in a UTF-8 sequence.
    let source = [0x66, 0x6f, 0x80, 0x6f];
    let os_str = OsStr::from_bytes(&source[..]);

    assert_eq!(os_str.to_string_lossy(), "fo�o");
}
#[cfg(windows)] {
    use std::ffi::OsString;
    use std::os::windows::prelude::*;

    // Here the values 0x0066 and 0x006f correspond to 'f' and 'o'
    // respectively. The value 0xD800 is a lone surrogate half, invalid
    // in a UTF-16 sequence.
    let source = [0x0066, 0x006f, 0xD800, 0x006f];
    let os_string = OsString::from_wide(&source[..]);
    let os_str = os_string.as_os_str();

    assert_eq!(os_str.to_string_lossy(), "fo�o");
}

pub fn to_os_string(&self) -> OsString

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"));

pub fn is_empty(&self) -> bool

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());

pub fn len(&self) -> usize

Returns the length of this OsStr.

Note that this does not return the number of bytes in the string in OS string form.

The length returned is that of the underlying storage used by OsStr. As discussed in the OsString introduction, OsString and OsStr store strings in a form best suited for cheap inter-conversion between native-platform and Rust string forms, which may differ significantly from both of them, including in storage size and encoding.

This number is simply useful for passing to other methods, like OsString::with_capacity to avoid reallocations.

See the main OsString documentation information about encoding and capacity units.

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);

pub fn as_encoded_bytes(&self) -> &[u8]

Converts an OS string slice to a byte slice. To convert the byte slice back into an OS string slice, use the OsStr::from_encoded_bytes_unchecked function.

The byte encoding is an unspecified, platform-specific, self-synchronizing superset of UTF-8. By being a self-synchronizing superset of UTF-8, this encoding is also a superset of 7-bit ASCII.

Note: As the encoding is unspecified, any sub-slice of bytes that is not valid UTF-8 should be treated as opaque and only comparable within the same Rust version built for the same target platform. For example, sending the slice over the network or storing it in a file will likely result in incompatible byte slices. See OsString for more encoding details and std::ffi for platform-specific, specified conversions.

pub fn slice_encoded_bytes<R>(&self, range: R) -> &OsStr

where R: RangeBounds<usize>,

🔬This is a nightly-only experimental API. (os_str_slice)

Takes a substring based on a range that corresponds to the return value of OsStr::as_encoded_bytes.

The range’s start and end must lie on valid OsStr boundaries. A valid OsStr boundary is one of:

• The start of the string
• The end of the string
• Immediately before a valid non-empty UTF-8 substring
• Immediately after a valid non-empty UTF-8 substring

Panics

Panics if range does not lie on valid OsStr boundaries or if it exceeds the end of the string.

Example

#![feature(os_str_slice)]

use std::ffi::OsStr;

let os_str = OsStr::new("foo=bar");
let bytes = os_str.as_encoded_bytes();
if let Some(index) = bytes.iter().position(|b| *b == b'=') {
    let key = os_str.slice_encoded_bytes(..index);
    let value = os_str.slice_encoded_bytes(index + 1..);
    assert_eq!(key, "foo");
    assert_eq!(value, "bar");
}

pub fn make_ascii_lowercase(&mut self)

Converts this string to its ASCII lower case equivalent in-place.

ASCII letters ‘A’ to ‘Z’ are mapped to ‘a’ to ‘z’, but non-ASCII letters are unchanged.

To return a new lowercased value without modifying the existing one, use OsStr::to_ascii_lowercase.

Examples

use std::ffi::OsString;

let mut s = OsString::from("GRÜßE, JÜRGEN ❤");

s.make_ascii_lowercase();

assert_eq!("grÜße, jÜrgen ❤", s);

pub fn make_ascii_uppercase(&mut self)

Converts this string to its ASCII upper case equivalent in-place.

ASCII letters ‘a’ to ‘z’ are mapped to ‘A’ to ‘Z’, but non-ASCII letters are unchanged.

To return a new uppercased value without modifying the existing one, use OsStr::to_ascii_uppercase.

Examples

use std::ffi::OsString;

let mut s = OsString::from("Grüße, Jürgen ❤");

s.make_ascii_uppercase();

assert_eq!("GRüßE, JüRGEN ❤", s);

pub fn to_ascii_lowercase(&self) -> OsString

Returns a copy of this string where each character is mapped to its ASCII lower case equivalent.

ASCII letters ‘A’ to ‘Z’ are mapped to ‘a’ to ‘z’, but non-ASCII letters are unchanged.

To lowercase the value in-place, use OsStr::make_ascii_lowercase.

Examples

use std::ffi::OsString;
let s = OsString::from("Grüße, Jürgen ❤");

assert_eq!("grüße, jürgen ❤", s.to_ascii_lowercase());

pub fn to_ascii_uppercase(&self) -> OsString

Returns a copy of this string where each character is mapped to its ASCII upper case equivalent.

ASCII letters ‘a’ to ‘z’ are mapped to ‘A’ to ‘Z’, but non-ASCII letters are unchanged.

To uppercase the value in-place, use OsStr::make_ascii_uppercase.

Examples

use std::ffi::OsString;
let s = OsString::from("Grüße, Jürgen ❤");

assert_eq!("GRüßE, JüRGEN ❤", s.to_ascii_uppercase());

pub fn is_ascii(&self) -> bool

Checks if all characters in this string are within the ASCII range.

Examples

use std::ffi::OsString;

let ascii = OsString::from("hello!\n");
let non_ascii = OsString::from("Grüße, Jürgen ❤");

assert!(ascii.is_ascii());
assert!(!non_ascii.is_ascii());

pub fn eq_ignore_ascii_case<S>(&self, other: S) -> bool

where S: AsRef<OsStr>,

Checks that two strings are an ASCII case-insensitive match.

Same as to_ascii_lowercase(a) == to_ascii_lowercase(b), but without allocating and copying temporaries.

Examples

use std::ffi::OsString;

assert!(OsString::from("Ferris").eq_ignore_ascii_case("FERRIS"));
assert!(OsString::from("Ferrös").eq_ignore_ascii_case("FERRöS"));
assert!(!OsString::from("Ferrös").eq_ignore_ascii_case("FERRÖS"));

pub fn display(&self) -> Display<'_>

Returns an object that implements Display for safely printing an OsStr that may contain non-Unicode data. This may perform lossy conversion, depending on the platform. If you would like an implementation which escapes the OsStr please use Debug instead.

Examples

use std::ffi::OsStr;

let s = OsStr::new("Hello, world!");
println!("{}", s.display());

Trait Implementations

impl Argument for &OsArgument

type ShortOpt = ShortOpt

The short-flag type. For &str, this is char. For &[u8], this is u8.

fn ends_opts(self) -> bool

Returns true if this argument signals that no additional options should be parsed. If this method returns true, then Options::next_opt will not attempt to parse it as one (parse_long_opt and parse_short_cluster will not be called).

fn parse_long_opt(self) -> Option<(Self, Option<Self>)>

Attempts to parse this argument as a long option. Returns the result of the parsing operation, with the leading -- stripped.

fn parse_short_cluster(self) -> Option<Self>

Attempts to parse this argument as a “short option cluster”. Returns the short option cluster if present.

fn consume_short_opt(self) -> (Self::ShortOpt, Option<Self>)

Attempts to consume one short option from a “short option cluster”, as defined by parse_short_cluster. Returns the short option that was consumed and the rest of the cluster (if non-empty).

fn consume_short_val(self) -> Self

Consumes the value of a short option from a “short option cluster”, as defined by parse_short_cluster. Returns the value that was consumed.

impl Debug for OsArgument

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Deref for OsArgument

type Target = OsStr

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl DerefMut for OsArgument

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl<'a> From<&'a OsArgument> for &'a OsStr

fn from(from: &'a OsArgument) -> Self

Converts to this type from the input type.

impl<'a> From<&'a OsStr> for &'a OsArgument

fn from(from: &'a OsStr) -> Self

Converts to this type from the input type.

impl Hash for OsArgument

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

impl PartialEq for OsArgument

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

const fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for OsArgument