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@@ -0,0 +1,1238 @@
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+// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
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+// file at the top-level directory of this distribution and at
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+// http://rust-lang.org/COPYRIGHT.
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+//
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+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
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+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
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+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
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+// option. This file may not be copied, modified, or distributed
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+// except according to those terms.
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+
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+use alloc::arc::Arc;
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+use alloc::borrow::{Borrow, Cow, ToOwned};
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+use alloc::boxed::Box;
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+use alloc::rc::Rc;
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+use alloc::string::String;
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+use alloc::vec::Vec;
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+use core::ascii;
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+use core::cmp::Ordering;
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+use core::fmt::{self, Write};
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+use core::mem;
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+use core::ops;
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+use core::ptr;
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+use core::slice;
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+use core::str::{self, Utf8Error};
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+
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+use header::string::strlen;
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+use platform::types::*;
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+
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+pub fn memchr(needle: u8, haystack: &[u8]) -> Option<usize> {
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+ use header::string;
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+
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+ let p = unsafe {
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+ string::memchr(
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+ haystack.as_ptr() as *const c_void,
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+ needle as c_int,
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+ haystack.len())
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+ };
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+ if p.is_null() {
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+ None
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+ } else {
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+ Some(p as usize - (haystack.as_ptr() as usize))
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+ }
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+}
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+
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+/// A type representing an owned, C-compatible, nul-terminated string with no nul bytes in the
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+/// middle.
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+///
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+/// This type serves the purpose of being able to safely generate a
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+/// C-compatible string from a Rust byte slice or vector. An instance of this
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+/// type is a static guarantee that the underlying bytes contain no interior 0
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+/// bytes ("nul characters") and that the final byte is 0 ("nul terminator").
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+///
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+/// `CString` is to [`CStr`] as [`String`] is to [`&str`]: the former
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+/// in each pair are owned strings; the latter are borrowed
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+/// references.
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+///
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+/// # Creating a `CString`
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+///
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+/// A `CString` is created from either a byte slice or a byte vector,
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+/// or anything that implements [`Into`]`<`[`Vec`]`<`[`u8`]`>>` (for
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+/// example, you can build a `CString` straight out of a [`String`] or
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+/// a [`&str`], since both implement that trait).
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+///
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+/// The [`new`] method will actually check that the provided `&[u8]`
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+/// does not have 0 bytes in the middle, and return an error if it
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+/// finds one.
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+///
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+/// # Extracting a raw pointer to the whole C string
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+///
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+/// `CString` implements a [`as_ptr`] method through the [`Deref`]
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+/// trait. This method will give you a `*const c_char` which you can
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+/// feed directly to extern functions that expect a nul-terminated
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+/// string, like C's `strdup()`.
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+///
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+/// # Extracting a slice of the whole C string
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+///
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+/// Alternatively, you can obtain a `&[`[`u8`]`]` slice from a
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+/// `CString` with the [`as_bytes`] method. Slices produced in this
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+/// way do *not* contain the trailing nul terminator. This is useful
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+/// when you will be calling an extern function that takes a `*const
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+/// u8` argument which is not necessarily nul-terminated, plus another
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+/// argument with the length of the string — like C's `strndup()`.
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+/// You can of course get the slice's length with its
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+/// [`len`][slice.len] method.
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+///
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+/// If you need a `&[`[`u8`]`]` slice *with* the nul terminator, you
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+/// can use [`as_bytes_with_nul`] instead.
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+///
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+/// Once you have the kind of slice you need (with or without a nul
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+/// terminator), you can call the slice's own
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+/// [`as_ptr`][slice.as_ptr] method to get a raw pointer to pass to
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+/// extern functions. See the documentation for that function for a
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+/// discussion on ensuring the lifetime of the raw pointer.
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+///
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+/// [`Into`]: ../convert/trait.Into.html
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+/// [`Vec`]: ../vec/struct.Vec.html
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+/// [`String`]: ../string/struct.String.html
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+/// [`&str`]: ../primitive.str.html
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+/// [`u8`]: ../primitive.u8.html
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+/// [`new`]: #method.new
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+/// [`as_bytes`]: #method.as_bytes
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+/// [`as_bytes_with_nul`]: #method.as_bytes_with_nul
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+/// [`as_ptr`]: #method.as_ptr
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+/// [slice.as_ptr]: ../primitive.slice.html#method.as_ptr
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+/// [slice.len]: ../primitive.slice.html#method.len
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+/// [`Deref`]: ../ops/trait.Deref.html
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+/// [`CStr`]: struct.CStr.html
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+///
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+/// # Examples
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+///
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+/// ```ignore (extern-declaration)
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+/// # fn main() {
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+/// use std::ffi::CString;
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+/// use std::os::raw::c_char;
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+///
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+/// extern {
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+/// fn my_printer(s: *const c_char);
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+/// }
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+///
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+/// // We are certain that our string doesn't have 0 bytes in the middle,
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+/// // so we can .unwrap()
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+/// let c_to_print = CString::new("Hello, world!").unwrap();
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+/// unsafe {
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+/// my_printer(c_to_print.as_ptr());
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+/// }
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+/// # }
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+/// ```
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+///
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+/// # Safety
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+///
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+/// `CString` is intended for working with traditional C-style strings
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+/// (a sequence of non-nul bytes terminated by a single nul byte); the
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+/// primary use case for these kinds of strings is interoperating with C-like
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+/// code. Often you will need to transfer ownership to/from that external
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+/// code. It is strongly recommended that you thoroughly read through the
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+/// documentation of `CString` before use, as improper ownership management
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+/// of `CString` instances can lead to invalid memory accesses, memory leaks,
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+/// and other memory errors.
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+
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+#[derive(PartialEq, PartialOrd, Eq, Ord, Hash, Clone)]
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+pub struct CString {
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+ // Invariant 1: the slice ends with a zero byte and has a length of at least one.
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+ // Invariant 2: the slice contains only one zero byte.
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+ // Improper usage of unsafe function can break Invariant 2, but not Invariant 1.
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+ inner: Box<[u8]>,
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+}
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+
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+/// Representation of a borrowed C string.
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+///
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+/// This type represents a borrowed reference to a nul-terminated
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+/// array of bytes. It can be constructed safely from a `&[`[`u8`]`]`
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+/// slice, or unsafely from a raw `*const c_char`. It can then be
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+/// converted to a Rust [`&str`] by performing UTF-8 validation, or
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+/// into an owned [`CString`].
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+///
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+/// `CStr` is to [`CString`] as [`&str`] is to [`String`]: the former
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+/// in each pair are borrowed references; the latter are owned
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+/// strings.
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+///
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+/// Note that this structure is **not** `repr(C)` and is not recommended to be
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+/// placed in the signatures of FFI functions. Instead, safe wrappers of FFI
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+/// functions may leverage the unsafe [`from_ptr`] constructor to provide a safe
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+/// interface to other consumers.
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+///
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+/// # Examples
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+///
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+/// Inspecting a foreign C string:
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+///
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+/// ```ignore (extern-declaration)
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+/// use std::ffi::CStr;
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+/// use std::os::raw::c_char;
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+///
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+/// extern { fn my_string() -> *const c_char; }
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+///
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+/// unsafe {
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+/// let slice = CStr::from_ptr(my_string());
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+/// println!("string buffer size without nul terminator: {}", slice.to_bytes().len());
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+/// }
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+/// ```
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+///
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+/// Passing a Rust-originating C string:
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+///
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+/// ```ignore (extern-declaration)
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+/// use std::ffi::{CString, CStr};
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+/// use std::os::raw::c_char;
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+///
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+/// fn work(data: &CStr) {
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+/// extern { fn work_with(data: *const c_char); }
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+///
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+/// unsafe { work_with(data.as_ptr()) }
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+/// }
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+///
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+/// let s = CString::new("data data data data").unwrap();
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+/// work(&s);
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+/// ```
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+///
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+/// Converting a foreign C string into a Rust [`String`]:
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+///
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+/// ```ignore (extern-declaration)
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+/// use std::ffi::CStr;
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+/// use std::os::raw::c_char;
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+///
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+/// extern { fn my_string() -> *const c_char; }
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+///
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+/// fn my_string_safe() -> String {
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+/// unsafe {
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+/// CStr::from_ptr(my_string()).to_string_lossy().into_owned()
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+/// }
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+/// }
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+///
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+/// println!("string: {}", my_string_safe());
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+/// ```
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+///
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+/// [`u8`]: ../primitive.u8.html
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+/// [`&str`]: ../primitive.str.html
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+/// [`String`]: ../string/struct.String.html
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+/// [`CString`]: struct.CString.html
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+/// [`from_ptr`]: #method.from_ptr
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+#[derive(Hash)]
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+pub struct CStr {
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+ // FIXME: this should not be represented with a DST slice but rather with
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+ // just a raw `c_char` along with some form of marker to make
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+ // this an unsized type. Essentially `sizeof(&CStr)` should be the
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+ // same as `sizeof(&c_char)` but `CStr` should be an unsized type.
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+ inner: [c_char]
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+}
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+
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+/// An error indicating that an interior nul byte was found.
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+///
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+/// While Rust strings may contain nul bytes in the middle, C strings
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+/// can't, as that byte would effectively truncate the string.
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+///
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+/// This error is created by the [`new`][`CString::new`] method on
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+/// [`CString`]. See its documentation for more.
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+///
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+/// [`CString`]: struct.CString.html
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+/// [`CString::new`]: struct.CString.html#method.new
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+///
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+/// # Examples
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+///
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+/// ```
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+/// use std::ffi::{CString, NulError};
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+///
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+/// let _: NulError = CString::new(b"f\0oo".to_vec()).unwrap_err();
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+/// ```
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+#[derive(Clone, PartialEq, Eq, Debug)]
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+pub struct NulError(usize, Vec<u8>);
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+
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+/// An error indicating that a nul byte was not in the expected position.
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+///
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+/// The slice used to create a [`CStr`] must have one and only one nul
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+/// byte at the end of the slice.
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+///
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+/// This error is created by the
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+/// [`from_bytes_with_nul`][`CStr::from_bytes_with_nul`] method on
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+/// [`CStr`]. See its documentation for more.
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+///
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+/// [`CStr`]: struct.CStr.html
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+/// [`CStr::from_bytes_with_nul`]: struct.CStr.html#method.from_bytes_with_nul
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+///
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+/// # Examples
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+///
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+/// ```
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+/// use std::ffi::{CStr, FromBytesWithNulError};
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+///
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+/// let _: FromBytesWithNulError = CStr::from_bytes_with_nul(b"f\0oo").unwrap_err();
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+/// ```
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+#[derive(Clone, PartialEq, Eq, Debug)]
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+pub struct FromBytesWithNulError {
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+ kind: FromBytesWithNulErrorKind,
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+}
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+
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+#[derive(Clone, PartialEq, Eq, Debug)]
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+enum FromBytesWithNulErrorKind {
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+ InteriorNul(usize),
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+ NotNulTerminated,
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+}
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+
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+impl FromBytesWithNulError {
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+ fn interior_nul(pos: usize) -> FromBytesWithNulError {
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+ FromBytesWithNulError {
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+ kind: FromBytesWithNulErrorKind::InteriorNul(pos),
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+ }
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+ }
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+ fn not_nul_terminated() -> FromBytesWithNulError {
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+ FromBytesWithNulError {
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+ kind: FromBytesWithNulErrorKind::NotNulTerminated,
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+ }
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+ }
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+
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+ fn description(&self) -> &str {
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+ match self.kind {
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+ FromBytesWithNulErrorKind::InteriorNul(..) =>
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+ "data provided contains an interior nul byte",
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+ FromBytesWithNulErrorKind::NotNulTerminated =>
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+ "data provided is not nul terminated",
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+ }
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+ }
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+}
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+
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+/// An error indicating invalid UTF-8 when converting a [`CString`] into a [`String`].
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+///
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+/// `CString` is just a wrapper over a buffer of bytes with a nul
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+/// terminator; [`into_string`][`CString::into_string`] performs UTF-8
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+/// validation on those bytes and may return this error.
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+///
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+/// This `struct` is created by the
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+/// [`into_string`][`CString::into_string`] method on [`CString`]. See
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+/// its documentation for more.
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+///
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+/// [`String`]: ../string/struct.String.html
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+/// [`CString`]: struct.CString.html
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+/// [`CString::into_string`]: struct.CString.html#method.into_string
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+#[derive(Clone, PartialEq, Eq, Debug)]
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+pub struct IntoStringError {
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+ inner: CString,
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+ error: Utf8Error,
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+}
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+
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+impl CString {
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+ /// Creates a new C-compatible string from a container of bytes.
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+ ///
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+ /// This function will consume the provided data and use the
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+ /// underlying bytes to construct a new string, ensuring that
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+ /// there is a trailing 0 byte. This trailing 0 byte will be
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+ /// appended by this function; the provided data should *not*
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+ /// contain any 0 bytes in it.
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+ ///
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+ /// # Examples
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+ ///
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+ /// ```ignore (extern-declaration)
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+ /// use std::ffi::CString;
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+ /// use std::os::raw::c_char;
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+ ///
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+ /// extern { fn puts(s: *const c_char); }
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+ ///
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+ /// let to_print = CString::new("Hello!").unwrap();
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+ /// unsafe {
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+ /// puts(to_print.as_ptr());
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+ /// }
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+ /// ```
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+ ///
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+ /// # Errors
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+ ///
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+ /// This function will return an error if the supplied bytes contain an
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+ /// internal 0 byte. The [`NulError`] returned will contain the bytes as well as
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+ /// the position of the nul byte.
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+ ///
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+ /// [`NulError`]: struct.NulError.html
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+ pub fn new<T: Into<Vec<u8>>>(t: T) -> Result<CString, NulError> {
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+ Self::_new(t.into())
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+ }
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+
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+ fn _new(bytes: Vec<u8>) -> Result<CString, NulError> {
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+ match memchr(0, &bytes) {
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+ Some(i) => Err(NulError(i, bytes)),
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+ None => Ok(unsafe { CString::from_vec_unchecked(bytes) }),
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+ }
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+ }
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+
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+ /// Creates a C-compatible string by consuming a byte vector,
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+ /// without checking for interior 0 bytes.
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+ ///
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+ /// This method is equivalent to [`new`] except that no runtime assertion
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+ /// is made that `v` contains no 0 bytes, and it requires an actual
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+ /// byte vector, not anything that can be converted to one with Into.
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+ ///
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+ /// [`new`]: #method.new
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+ ///
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+ /// # Examples
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+ ///
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+ /// ```
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+ /// use std::ffi::CString;
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+ ///
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+ /// let raw = b"foo".to_vec();
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+ /// unsafe {
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+ /// let c_string = CString::from_vec_unchecked(raw);
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+ /// }
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+ /// ```
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+ pub unsafe fn from_vec_unchecked(mut v: Vec<u8>) -> CString {
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+ v.reserve_exact(1);
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+ v.push(0);
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+ CString { inner: v.into_boxed_slice() }
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|
|
+ }
|
|
|
+
|
|
|
+ /// Retakes ownership of a `CString` that was transferred to C via [`into_raw`].
|
|
|
+ ///
|
|
|
+ /// Additionally, the length of the string will be recalculated from the pointer.
|
|
|
+ ///
|
|
|
+ /// # Safety
|
|
|
+ ///
|
|
|
+ /// This should only ever be called with a pointer that was earlier
|
|
|
+ /// obtained by calling [`into_raw`] on a `CString`. Other usage (e.g. trying to take
|
|
|
+ /// ownership of a string that was allocated by foreign code) is likely to lead
|
|
|
+ /// to undefined behavior or allocator corruption.
|
|
|
+ ///
|
|
|
+ /// > **Note:** If you need to borrow a string that was allocated by
|
|
|
+ /// > foreign code, use [`CStr`]. If you need to take ownership of
|
|
|
+ /// > a string that was allocated by foreign code, you will need to
|
|
|
+ /// > make your own provisions for freeing it appropriately, likely
|
|
|
+ /// > with the foreign code's API to do that.
|
|
|
+ ///
|
|
|
+ /// [`into_raw`]: #method.into_raw
|
|
|
+ /// [`CStr`]: struct.CStr.html
|
|
|
+ ///
|
|
|
+ /// # Examples
|
|
|
+ ///
|
|
|
+ /// Create a `CString`, pass ownership to an `extern` function (via raw pointer), then retake
|
|
|
+ /// ownership with `from_raw`:
|
|
|
+ ///
|
|
|
+ /// ```ignore (extern-declaration)
|
|
|
+ /// use std::ffi::CString;
|
|
|
+ /// use std::os::raw::c_char;
|
|
|
+ ///
|
|
|
+ /// extern {
|
|
|
+ /// fn some_extern_function(s: *mut c_char);
|
|
|
+ /// }
|
|
|
+ ///
|
|
|
+ /// let c_string = CString::new("Hello!").unwrap();
|
|
|
+ /// let raw = c_string.into_raw();
|
|
|
+ /// unsafe {
|
|
|
+ /// some_extern_function(raw);
|
|
|
+ /// let c_string = CString::from_raw(raw);
|
|
|
+ /// }
|
|
|
+ /// ```
|
|
|
+ pub unsafe fn from_raw(ptr: *mut c_char) -> CString {
|
|
|
+ let len = strlen(ptr) + 1; // Including the NUL byte
|
|
|
+ let slice = slice::from_raw_parts_mut(ptr, len as usize);
|
|
|
+ CString { inner: Box::from_raw(slice as *mut [c_char] as *mut [u8]) }
|
|
|
+ }
|
|
|
+
|
|
|
+ /// Consumes the `CString` and transfers ownership of the string to a C caller.
|
|
|
+ ///
|
|
|
+ /// The pointer which this function returns must be returned to Rust and reconstituted using
|
|
|
+ /// [`from_raw`] to be properly deallocated. Specifically, one
|
|
|
+ /// should *not* use the standard C `free()` function to deallocate
|
|
|
+ /// this string.
|
|
|
+ ///
|
|
|
+ /// Failure to call [`from_raw`] will lead to a memory leak.
|
|
|
+ ///
|
|
|
+ /// [`from_raw`]: #method.from_raw
|
|
|
+ ///
|
|
|
+ /// # Examples
|
|
|
+ ///
|
|
|
+ /// ```
|
|
|
+ /// use std::ffi::CString;
|
|
|
+ ///
|
|
|
+ /// let c_string = CString::new("foo").unwrap();
|
|
|
+ ///
|
|
|
+ /// let ptr = c_string.into_raw();
|
|
|
+ ///
|
|
|
+ /// unsafe {
|
|
|
+ /// assert_eq!(b'f', *ptr as u8);
|
|
|
+ /// assert_eq!(b'o', *ptr.offset(1) as u8);
|
|
|
+ /// assert_eq!(b'o', *ptr.offset(2) as u8);
|
|
|
+ /// assert_eq!(b'\0', *ptr.offset(3) as u8);
|
|
|
+ ///
|
|
|
+ /// // retake pointer to free memory
|
|
|
+ /// let _ = CString::from_raw(ptr);
|
|
|
+ /// }
|
|
|
+ /// ```
|
|
|
+ #[inline]
|
|
|
+ pub fn into_raw(self) -> *mut c_char {
|
|
|
+ Box::into_raw(self.into_inner()) as *mut c_char
|
|
|
+ }
|
|
|
+
|
|
|
+ /// Converts the `CString` into a [`String`] if it contains valid UTF-8 data.
|
|
|
+ ///
|
|
|
+ /// On failure, ownership of the original `CString` is returned.
|
|
|
+ ///
|
|
|
+ /// [`String`]: ../string/struct.String.html
|
|
|
+ ///
|
|
|
+ /// # Examples
|
|
|
+ ///
|
|
|
+ /// ```
|
|
|
+ /// use std::ffi::CString;
|
|
|
+ ///
|
|
|
+ /// let valid_utf8 = vec![b'f', b'o', b'o'];
|
|
|
+ /// let cstring = CString::new(valid_utf8).unwrap();
|
|
|
+ /// assert_eq!(cstring.into_string().unwrap(), "foo");
|
|
|
+ ///
|
|
|
+ /// let invalid_utf8 = vec![b'f', 0xff, b'o', b'o'];
|
|
|
+ /// let cstring = CString::new(invalid_utf8).unwrap();
|
|
|
+ /// let err = cstring.into_string().err().unwrap();
|
|
|
+ /// assert_eq!(err.utf8_error().valid_up_to(), 1);
|
|
|
+ /// ```
|
|
|
+
|
|
|
+ pub fn into_string(self) -> Result<String, IntoStringError> {
|
|
|
+ String::from_utf8(self.into_bytes())
|
|
|
+ .map_err(|e| IntoStringError {
|
|
|
+ error: e.utf8_error(),
|
|
|
+ inner: unsafe { CString::from_vec_unchecked(e.into_bytes()) },
|
|
|
+ })
|
|
|
+ }
|
|
|
+
|
|
|
+ /// Consumes the `CString` and returns the underlying byte buffer.
|
|
|
+ ///
|
|
|
+ /// The returned buffer does **not** contain the trailing nul
|
|
|
+ /// terminator, and it is guaranteed to not have any interior nul
|
|
|
+ /// bytes.
|
|
|
+ ///
|
|
|
+ /// # Examples
|
|
|
+ ///
|
|
|
+ /// ```
|
|
|
+ /// use std::ffi::CString;
|
|
|
+ ///
|
|
|
+ /// let c_string = CString::new("foo").unwrap();
|
|
|
+ /// let bytes = c_string.into_bytes();
|
|
|
+ /// assert_eq!(bytes, vec![b'f', b'o', b'o']);
|
|
|
+ /// ```
|
|
|
+ pub fn into_bytes(self) -> Vec<u8> {
|
|
|
+ let mut vec = self.into_inner().into_vec();
|
|
|
+ let _nul = vec.pop();
|
|
|
+ debug_assert_eq!(_nul, Some(0u8));
|
|
|
+ vec
|
|
|
+ }
|
|
|
+
|
|
|
+ /// Equivalent to the [`into_bytes`] function except that the returned vector
|
|
|
+ /// includes the trailing nul terminator.
|
|
|
+ ///
|
|
|
+ /// [`into_bytes`]: #method.into_bytes
|
|
|
+ ///
|
|
|
+ /// # Examples
|
|
|
+ ///
|
|
|
+ /// ```
|
|
|
+ /// use std::ffi::CString;
|
|
|
+ ///
|
|
|
+ /// let c_string = CString::new("foo").unwrap();
|
|
|
+ /// let bytes = c_string.into_bytes_with_nul();
|
|
|
+ /// assert_eq!(bytes, vec![b'f', b'o', b'o', b'\0']);
|
|
|
+ /// ```
|
|
|
+ pub fn into_bytes_with_nul(self) -> Vec<u8> {
|
|
|
+ self.into_inner().into_vec()
|
|
|
+ }
|
|
|
+
|
|
|
+ /// Returns the contents of this `CString` as a slice of bytes.
|
|
|
+ ///
|
|
|
+ /// The returned slice does **not** contain the trailing nul
|
|
|
+ /// terminator, and it is guaranteed to not have any interior nul
|
|
|
+ /// bytes. If you need the nul terminator, use
|
|
|
+ /// [`as_bytes_with_nul`] instead.
|
|
|
+ ///
|
|
|
+ /// [`as_bytes_with_nul`]: #method.as_bytes_with_nul
|
|
|
+ ///
|
|
|
+ /// # Examples
|
|
|
+ ///
|
|
|
+ /// ```
|
|
|
+ /// use std::ffi::CString;
|
|
|
+ ///
|
|
|
+ /// let c_string = CString::new("foo").unwrap();
|
|
|
+ /// let bytes = c_string.as_bytes();
|
|
|
+ /// assert_eq!(bytes, &[b'f', b'o', b'o']);
|
|
|
+ /// ```
|
|
|
+ #[inline]
|
|
|
+ pub fn as_bytes(&self) -> &[u8] {
|
|
|
+ &self.inner[..self.inner.len() - 1]
|
|
|
+ }
|
|
|
+
|
|
|
+ /// Equivalent to the [`as_bytes`] function except that the returned slice
|
|
|
+ /// includes the trailing nul terminator.
|
|
|
+ ///
|
|
|
+ /// [`as_bytes`]: #method.as_bytes
|
|
|
+ ///
|
|
|
+ /// # Examples
|
|
|
+ ///
|
|
|
+ /// ```
|
|
|
+ /// use std::ffi::CString;
|
|
|
+ ///
|
|
|
+ /// let c_string = CString::new("foo").unwrap();
|
|
|
+ /// let bytes = c_string.as_bytes_with_nul();
|
|
|
+ /// assert_eq!(bytes, &[b'f', b'o', b'o', b'\0']);
|
|
|
+ /// ```
|
|
|
+ #[inline]
|
|
|
+ pub fn as_bytes_with_nul(&self) -> &[u8] {
|
|
|
+ &self.inner
|
|
|
+ }
|
|
|
+
|
|
|
+ /// Extracts a [`CStr`] slice containing the entire string.
|
|
|
+ ///
|
|
|
+ /// [`CStr`]: struct.CStr.html
|
|
|
+ ///
|
|
|
+ /// # Examples
|
|
|
+ ///
|
|
|
+ /// ```
|
|
|
+ /// use std::ffi::{CString, CStr};
|
|
|
+ ///
|
|
|
+ /// let c_string = CString::new(b"foo".to_vec()).unwrap();
|
|
|
+ /// let c_str = c_string.as_c_str();
|
|
|
+ /// assert_eq!(c_str, CStr::from_bytes_with_nul(b"foo\0").unwrap());
|
|
|
+ /// ```
|
|
|
+ #[inline]
|
|
|
+ pub fn as_c_str(&self) -> &CStr {
|
|
|
+ &*self
|
|
|
+ }
|
|
|
+
|
|
|
+ /// Converts this `CString` into a boxed [`CStr`].
|
|
|
+ ///
|
|
|
+ /// [`CStr`]: struct.CStr.html
|
|
|
+ ///
|
|
|
+ /// # Examples
|
|
|
+ ///
|
|
|
+ /// ```
|
|
|
+ /// use std::ffi::{CString, CStr};
|
|
|
+ ///
|
|
|
+ /// let c_string = CString::new(b"foo".to_vec()).unwrap();
|
|
|
+ /// let boxed = c_string.into_boxed_c_str();
|
|
|
+ /// assert_eq!(&*boxed, CStr::from_bytes_with_nul(b"foo\0").unwrap());
|
|
|
+ /// ```
|
|
|
+ pub fn into_boxed_c_str(self) -> Box<CStr> {
|
|
|
+ unsafe { Box::from_raw(Box::into_raw(self.into_inner()) as *mut CStr) }
|
|
|
+ }
|
|
|
+
|
|
|
+ // Bypass "move out of struct which implements [`Drop`] trait" restriction.
|
|
|
+ ///
|
|
|
+ /// [`Drop`]: ../ops/trait.Drop.html
|
|
|
+ fn into_inner(self) -> Box<[u8]> {
|
|
|
+ unsafe {
|
|
|
+ let result = ptr::read(&self.inner);
|
|
|
+ mem::forget(self);
|
|
|
+ result
|
|
|
+ }
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+// Turns this `CString` into an empty string to prevent
|
|
|
+// memory unsafe code from working by accident. Inline
|
|
|
+// to prevent LLVM from optimizing it away in debug builds.
|
|
|
+impl Drop for CString {
|
|
|
+ #[inline]
|
|
|
+ fn drop(&mut self) {
|
|
|
+ unsafe { *self.inner.get_unchecked_mut(0) = 0; }
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl ops::Deref for CString {
|
|
|
+ type Target = CStr;
|
|
|
+
|
|
|
+ #[inline]
|
|
|
+ fn deref(&self) -> &CStr {
|
|
|
+ unsafe { CStr::from_bytes_with_nul_unchecked(self.as_bytes_with_nul()) }
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl fmt::Debug for CString {
|
|
|
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
|
+ fmt::Debug::fmt(&**self, f)
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl From<CString> for Vec<u8> {
|
|
|
+ /// Converts a [`CString`] into a [`Vec`]`<u8>`.
|
|
|
+ ///
|
|
|
+ /// The conversion consumes the [`CString`], and removes the terminating NUL byte.
|
|
|
+ ///
|
|
|
+ /// [`Vec`]: ../vec/struct.Vec.html
|
|
|
+ /// [`CString`]: ../ffi/struct.CString.html
|
|
|
+ #[inline]
|
|
|
+ fn from(s: CString) -> Vec<u8> {
|
|
|
+ s.into_bytes()
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl fmt::Debug for CStr {
|
|
|
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
|
+ write!(f, "\"")?;
|
|
|
+ for byte in self.to_bytes().iter().flat_map(|&b| ascii::escape_default(b)) {
|
|
|
+ f.write_char(byte as char)?;
|
|
|
+ }
|
|
|
+ write!(f, "\"")
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl<'a> Default for &'a CStr {
|
|
|
+ fn default() -> &'a CStr {
|
|
|
+ const SLICE: &'static [c_char] = &[0];
|
|
|
+ unsafe { CStr::from_ptr(SLICE.as_ptr()) }
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl Default for CString {
|
|
|
+ /// Creates an empty `CString`.
|
|
|
+ fn default() -> CString {
|
|
|
+ let a: &CStr = Default::default();
|
|
|
+ a.to_owned()
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl Borrow<CStr> for CString {
|
|
|
+ #[inline]
|
|
|
+ fn borrow(&self) -> &CStr { self }
|
|
|
+}
|
|
|
+
|
|
|
+impl<'a> From<Cow<'a, CStr>> for CString {
|
|
|
+ #[inline]
|
|
|
+ fn from(s: Cow<'a, CStr>) -> Self {
|
|
|
+ s.into_owned()
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl<'a> From<&'a CStr> for Box<CStr> {
|
|
|
+ fn from(s: &'a CStr) -> Box<CStr> {
|
|
|
+ let boxed: Box<[u8]> = Box::from(s.to_bytes_with_nul());
|
|
|
+ unsafe { Box::from_raw(Box::into_raw(boxed) as *mut CStr) }
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl From<Box<CStr>> for CString {
|
|
|
+ /// Converts a [`Box`]`<CStr>` into a [`CString`] without copying or allocating.
|
|
|
+ ///
|
|
|
+ /// [`Box`]: ../boxed/struct.Box.html
|
|
|
+ /// [`CString`]: ../ffi/struct.CString.html
|
|
|
+ #[inline]
|
|
|
+ fn from(s: Box<CStr>) -> CString {
|
|
|
+ s.into_c_string()
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl Clone for Box<CStr> {
|
|
|
+ #[inline]
|
|
|
+ fn clone(&self) -> Self {
|
|
|
+ (**self).into()
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl From<CString> for Box<CStr> {
|
|
|
+ /// Converts a [`CString`] into a [`Box`]`<CStr>` without copying or allocating.
|
|
|
+ ///
|
|
|
+ /// [`CString`]: ../ffi/struct.CString.html
|
|
|
+ /// [`Box`]: ../boxed/struct.Box.html
|
|
|
+ #[inline]
|
|
|
+ fn from(s: CString) -> Box<CStr> {
|
|
|
+ s.into_boxed_c_str()
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl<'a> From<CString> for Cow<'a, CStr> {
|
|
|
+ #[inline]
|
|
|
+ fn from(s: CString) -> Cow<'a, CStr> {
|
|
|
+ Cow::Owned(s)
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl<'a> From<&'a CStr> for Cow<'a, CStr> {
|
|
|
+ #[inline]
|
|
|
+ fn from(s: &'a CStr) -> Cow<'a, CStr> {
|
|
|
+ Cow::Borrowed(s)
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl<'a> From<&'a CString> for Cow<'a, CStr> {
|
|
|
+ #[inline]
|
|
|
+ fn from(s: &'a CString) -> Cow<'a, CStr> {
|
|
|
+ Cow::Borrowed(s.as_c_str())
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl From<CString> for Arc<CStr> {
|
|
|
+ /// Converts a [`CString`] into a [`Arc`]`<CStr>` without copying or allocating.
|
|
|
+ ///
|
|
|
+ /// [`CString`]: ../ffi/struct.CString.html
|
|
|
+ /// [`Arc`]: ../sync/struct.Arc.html
|
|
|
+ #[inline]
|
|
|
+ fn from(s: CString) -> Arc<CStr> {
|
|
|
+ let arc: Arc<[u8]> = Arc::from(s.into_inner());
|
|
|
+ unsafe { Arc::from_raw(Arc::into_raw(arc) as *const CStr) }
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl<'a> From<&'a CStr> for Arc<CStr> {
|
|
|
+ #[inline]
|
|
|
+ fn from(s: &CStr) -> Arc<CStr> {
|
|
|
+ let arc: Arc<[u8]> = Arc::from(s.to_bytes_with_nul());
|
|
|
+ unsafe { Arc::from_raw(Arc::into_raw(arc) as *const CStr) }
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl From<CString> for Rc<CStr> {
|
|
|
+ /// Converts a [`CString`] into a [`Rc`]`<CStr>` without copying or allocating.
|
|
|
+ ///
|
|
|
+ /// [`CString`]: ../ffi/struct.CString.html
|
|
|
+ /// [`Rc`]: ../rc/struct.Rc.html
|
|
|
+ #[inline]
|
|
|
+ fn from(s: CString) -> Rc<CStr> {
|
|
|
+ let rc: Rc<[u8]> = Rc::from(s.into_inner());
|
|
|
+ unsafe { Rc::from_raw(Rc::into_raw(rc) as *const CStr) }
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl<'a> From<&'a CStr> for Rc<CStr> {
|
|
|
+ #[inline]
|
|
|
+ fn from(s: &CStr) -> Rc<CStr> {
|
|
|
+ let rc: Rc<[u8]> = Rc::from(s.to_bytes_with_nul());
|
|
|
+ unsafe { Rc::from_raw(Rc::into_raw(rc) as *const CStr) }
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl Default for Box<CStr> {
|
|
|
+ fn default() -> Box<CStr> {
|
|
|
+ let boxed: Box<[u8]> = Box::from([0]);
|
|
|
+ unsafe { Box::from_raw(Box::into_raw(boxed) as *mut CStr) }
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl NulError {
|
|
|
+ /// Returns the position of the nul byte in the slice that caused
|
|
|
+ /// [`CString::new`] to fail.
|
|
|
+ ///
|
|
|
+ /// [`CString::new`]: struct.CString.html#method.new
|
|
|
+ ///
|
|
|
+ /// # Examples
|
|
|
+ ///
|
|
|
+ /// ```
|
|
|
+ /// use std::ffi::CString;
|
|
|
+ ///
|
|
|
+ /// let nul_error = CString::new("foo\0bar").unwrap_err();
|
|
|
+ /// assert_eq!(nul_error.nul_position(), 3);
|
|
|
+ ///
|
|
|
+ /// let nul_error = CString::new("foo bar\0").unwrap_err();
|
|
|
+ /// assert_eq!(nul_error.nul_position(), 7);
|
|
|
+ /// ```
|
|
|
+ pub fn nul_position(&self) -> usize { self.0 }
|
|
|
+
|
|
|
+ /// Consumes this error, returning the underlying vector of bytes which
|
|
|
+ /// generated the error in the first place.
|
|
|
+ ///
|
|
|
+ /// # Examples
|
|
|
+ ///
|
|
|
+ /// ```
|
|
|
+ /// use std::ffi::CString;
|
|
|
+ ///
|
|
|
+ /// let nul_error = CString::new("foo\0bar").unwrap_err();
|
|
|
+ /// assert_eq!(nul_error.into_vec(), b"foo\0bar");
|
|
|
+ /// ```
|
|
|
+ pub fn into_vec(self) -> Vec<u8> { self.1 }
|
|
|
+
|
|
|
+ fn description(&self) -> &str { "nul byte found in data" }
|
|
|
+}
|
|
|
+
|
|
|
+impl fmt::Display for NulError {
|
|
|
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
|
+ write!(f, "nul byte found in provided data at position: {}", self.0)
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl fmt::Display for FromBytesWithNulError {
|
|
|
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
|
+ f.write_str(self.description())?;
|
|
|
+ if let FromBytesWithNulErrorKind::InteriorNul(pos) = self.kind {
|
|
|
+ write!(f, " at byte pos {}", pos)?;
|
|
|
+ }
|
|
|
+ Ok(())
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl IntoStringError {
|
|
|
+ /// Consumes this error, returning original [`CString`] which generated the
|
|
|
+ /// error.
|
|
|
+ ///
|
|
|
+ /// [`CString`]: struct.CString.html
|
|
|
+ pub fn into_cstring(self) -> CString {
|
|
|
+ self.inner
|
|
|
+ }
|
|
|
+
|
|
|
+ /// Access the underlying UTF-8 error that was the cause of this error.
|
|
|
+ pub fn utf8_error(&self) -> Utf8Error {
|
|
|
+ self.error
|
|
|
+ }
|
|
|
+
|
|
|
+ fn description(&self) -> &str {
|
|
|
+ "C string contained non-utf8 bytes"
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl fmt::Display for IntoStringError {
|
|
|
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
|
|
|
+ self.description().fmt(f)
|
|
|
+ }
|
|
|
+}
|
|
|
+
|
|
|
+impl CStr {
|
|
|
+ /// Wraps a raw C string with a safe C string wrapper.
|
|
|
+ ///
|
|
|
+ /// This function will wrap the provided `ptr` with a `CStr` wrapper, which
|
|
|
+ /// allows inspection and interoperation of non-owned C strings. This method
|
|
|
+ /// is unsafe for a number of reasons:
|
|
|
+ ///
|
|
|
+ /// * There is no guarantee to the validity of `ptr`.
|
|
|
+ /// * The returned lifetime is not guaranteed to be the actual lifetime of
|
|
|
+ /// `ptr`.
|
|
|
+ /// * There is no guarantee that the memory pointed to by `ptr` contains a
|
|
|
+ /// valid nul terminator byte at the end of the string.
|
|
|
+ /// * It is not guaranteed that the memory pointed by `ptr` won't change
|
|
|
+ /// before the `CStr` has been destroyed.
|
|
|
+ ///
|
|
|
+ /// > **Note**: This operation is intended to be a 0-cost cast but it is
|
|
|
+ /// > currently implemented with an up-front calculation of the length of
|
|
|
+ /// > the string. This is not guaranteed to always be the case.
|
|
|
+ ///
|
|
|
+ /// # Examples
|
|
|
+ ///
|
|
|
+ /// ```ignore (extern-declaration)
|
|
|
+ /// # fn main() {
|
|
|
+ /// use std::ffi::CStr;
|
|
|
+ /// use std::os::raw::c_char;
|
|
|
+ ///
|
|
|
+ /// extern {
|
|
|
+ /// fn my_string() -> *const c_char;
|
|
|
+ /// }
|
|
|
+ ///
|
|
|
+ /// unsafe {
|
|
|
+ /// let slice = CStr::from_ptr(my_string());
|
|
|
+ /// println!("string returned: {}", slice.to_str().unwrap());
|
|
|
+ /// }
|
|
|
+ /// # }
|
|
|
+ /// ```
|
|
|
+ pub unsafe fn from_ptr<'a>(ptr: *const c_char) -> &'a CStr {
|
|
|
+ let len = strlen(ptr);
|
|
|
+ let ptr = ptr as *const u8;
|
|
|
+ CStr::from_bytes_with_nul_unchecked(slice::from_raw_parts(ptr, len as usize + 1))
|
|
|
+ }
|
|
|
+
|
|
|
+ /// Creates a C string wrapper from a byte slice.
|
|
|
+ ///
|
|
|
+ /// This function will cast the provided `bytes` to a `CStr`
|
|
|
+ /// wrapper after ensuring that the byte slice is nul-terminated
|
|
|
+ /// and does not contain any interior nul bytes.
|
|
|
+ ///
|
|
|
+ /// # Examples
|
|
|
+ ///
|
|
|
+ /// ```
|
|
|
+ /// use std::ffi::CStr;
|
|
|
+ ///
|
|
|
+ /// let cstr = CStr::from_bytes_with_nul(b"hello\0");
|
|
|
+ /// assert!(cstr.is_ok());
|
|
|
+ /// ```
|
|
|
+ ///
|
|
|
+ /// Creating a `CStr` without a trailing nul terminator is an error:
|
|
|
+ ///
|
|
|
+ /// ```
|
|
|
+ /// use std::ffi::CStr;
|
|
|
+ ///
|
|
|
+ /// let c_str = CStr::from_bytes_with_nul(b"hello");
|
|
|
+ /// assert!(c_str.is_err());
|
|
|
+ /// ```
|
|
|
+ ///
|
|
|
+ /// Creating a `CStr` with an interior nul byte is an error:
|
|
|
+ ///
|
|
|
+ /// ```
|
|
|
+ /// use std::ffi::CStr;
|
|
|
+ ///
|
|
|
+ /// let c_str = CStr::from_bytes_with_nul(b"he\0llo\0");
|
|
|
+ /// assert!(c_str.is_err());
|
|
|
+ /// ```
|
|
|
+ pub fn from_bytes_with_nul(bytes: &[u8])
|
|
|
+ -> Result<&CStr, FromBytesWithNulError> {
|
|
|
+ let nul_pos = memchr(0, bytes);
|
|
|
+ if let Some(nul_pos) = nul_pos {
|
|
|
+ if nul_pos + 1 != bytes.len() {
|
|
|
+ return Err(FromBytesWithNulError::interior_nul(nul_pos));
|
|
|
+ }
|
|
|
+ Ok(unsafe { CStr::from_bytes_with_nul_unchecked(bytes) })
|
|
|
+ } else {
|
|
|
+ Err(FromBytesWithNulError::not_nul_terminated())
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
+ /// Unsafely creates a C string wrapper from a byte slice.
|
|
|
+ ///
|
|
|
+ /// This function will cast the provided `bytes` to a `CStr` wrapper without
|
|
|
+ /// performing any sanity checks. The provided slice **must** be nul-terminated
|
|
|
+ /// and not contain any interior nul bytes.
|
|
|
+ ///
|
|
|
+ /// # Examples
|
|
|
+ ///
|
|
|
+ /// ```
|
|
|
+ /// use std::ffi::{CStr, CString};
|
|
|
+ ///
|
|
|
+ /// unsafe {
|
|
|
+ /// let cstring = CString::new("hello").unwrap();
|
|
|
+ /// let cstr = CStr::from_bytes_with_nul_unchecked(cstring.to_bytes_with_nul());
|
|
|
+ /// assert_eq!(cstr, &*cstring);
|
|
|
+ /// }
|
|
|
+ /// ```
|
|
|
+ #[inline]
|
|
|
+ pub unsafe fn from_bytes_with_nul_unchecked(bytes: &[u8]) -> &CStr {
|
|
|
+ &*(bytes as *const [u8] as *const CStr)
|
|
|
+ }
|
|
|
+
|
|
|
+ /// Returns the inner pointer to this C string.
|
|
|
+ ///
|
|
|
+ /// The returned pointer will be valid for as long as `self` is, and points
|
|
|
+ /// to a contiguous region of memory terminated with a 0 byte to represent
|
|
|
+ /// the end of the string.
|
|
|
+ ///
|
|
|
+ /// **WARNING**
|
|
|
+ ///
|
|
|
+ /// It is your responsibility to make sure that the underlying memory is not
|
|
|
+ /// freed too early. For example, the following code will cause undefined
|
|
|
+ /// behavior when `ptr` is used inside the `unsafe` block:
|
|
|
+ ///
|
|
|
+ /// ```no_run
|
|
|
+ /// # #![allow(unused_must_use)]
|
|
|
+ /// use std::ffi::{CString};
|
|
|
+ ///
|
|
|
+ /// let ptr = CString::new("Hello").unwrap().as_ptr();
|
|
|
+ /// unsafe {
|
|
|
+ /// // `ptr` is dangling
|
|
|
+ /// *ptr;
|
|
|
+ /// }
|
|
|
+ /// ```
|
|
|
+ ///
|
|
|
+ /// This happens because the pointer returned by `as_ptr` does not carry any
|
|
|
+ /// lifetime information and the [`CString`] is deallocated immediately after
|
|
|
+ /// the `CString::new("Hello").unwrap().as_ptr()` expression is evaluated.
|
|
|
+ /// To fix the problem, bind the `CString` to a local variable:
|
|
|
+ ///
|
|
|
+ /// ```no_run
|
|
|
+ /// # #![allow(unused_must_use)]
|
|
|
+ /// use std::ffi::{CString};
|
|
|
+ ///
|
|
|
+ /// let hello = CString::new("Hello").unwrap();
|
|
|
+ /// let ptr = hello.as_ptr();
|
|
|
+ /// unsafe {
|
|
|
+ /// // `ptr` is valid because `hello` is in scope
|
|
|
+ /// *ptr;
|
|
|
+ /// }
|
|
|
+ /// ```
|
|
|
+ ///
|
|
|
+ /// This way, the lifetime of the `CString` in `hello` encompasses
|
|
|
+ /// the lifetime of `ptr` and the `unsafe` block.
|
|
|
+ ///
|
|
|
+ /// [`CString`]: struct.CString.html
|
|
|
+ #[inline]
|
|
|
+ pub fn as_ptr(&self) -> *const c_char {
|
|
|
+ self.inner.as_ptr()
|
|
|
+ }
|
|
|
+
|
|
|
+ /// Converts this C string to a byte slice.
|
|
|
+ ///
|
|
|
+ /// The returned slice will **not** contain the trailing nul terminator that this C
|
|
|
+ /// string has.
|
|
|
+ ///
|
|
|
+ /// > **Note**: This method is currently implemented as a constant-time
|
|
|
+ /// > cast, but it is planned to alter its definition in the future to
|
|
|
+ /// > perform the length calculation whenever this method is called.
|
|
|
+ ///
|
|
|
+ /// # Examples
|
|
|
+ ///
|
|
|
+ /// ```
|
|
|
+ /// use std::ffi::CStr;
|
|
|
+ ///
|
|
|
+ /// let c_str = CStr::from_bytes_with_nul(b"foo\0").unwrap();
|
|
|
+ /// assert_eq!(c_str.to_bytes(), b"foo");
|
|
|
+ /// ```
|
|
|
+ #[inline]
|
|
|
+ pub fn to_bytes(&self) -> &[u8] {
|
|
|
+ let bytes = self.to_bytes_with_nul();
|
|
|
+ &bytes[..bytes.len() - 1]
|
|
|
+ }
|
|
|
+
|
|
|
+ /// Converts this C string to a byte slice containing the trailing 0 byte.
|
|
|
+ ///
|
|
|
+ /// This function is the equivalent of [`to_bytes`] except that it will retain
|
|
|
+ /// the trailing nul terminator instead of chopping it off.
|
|
|
+ ///
|
|
|
+ /// > **Note**: This method is currently implemented as a 0-cost cast, but
|
|
|
+ /// > it is planned to alter its definition in the future to perform the
|
|
|
+ /// > length calculation whenever this method is called.
|
|
|
+ ///
|
|
|
+ /// [`to_bytes`]: #method.to_bytes
|
|
|
+ ///
|
|
|
+ /// # Examples
|
|
|
+ ///
|
|
|
+ /// ```
|
|
|
+ /// use std::ffi::CStr;
|
|
|
+ ///
|
|
|
+ /// let c_str = CStr::from_bytes_with_nul(b"foo\0").unwrap();
|
|
|
+ /// assert_eq!(c_str.to_bytes_with_nul(), b"foo\0");
|
|
|
+ /// ```
|
|
|
+ #[inline]
|
|
|
+ pub fn to_bytes_with_nul(&self) -> &[u8] {
|
|
|
+ unsafe { &*(&self.inner as *const [c_char] as *const [u8]) }
|
|
|
+ }
|
|
|
+
|
|
|
+ /// Yields a [`&str`] slice if the `CStr` contains valid UTF-8.
|
|
|
+ ///
|
|
|
+ /// If the contents of the `CStr` are valid UTF-8 data, this
|
|
|
+ /// function will return the corresponding [`&str`] slice. Otherwise,
|
|
|
+ /// it will return an error with details of where UTF-8 validation failed.
|
|
|
+ ///
|
|
|
+ /// > **Note**: This method is currently implemented to check for validity
|
|
|
+ /// > after a constant-time cast, but it is planned to alter its definition
|
|
|
+ /// > in the future to perform the length calculation in addition to the
|
|
|
+ /// > UTF-8 check whenever this method is called.
|
|
|
+ ///
|
|
|
+ /// [`&str`]: ../primitive.str.html
|
|
|
+ ///
|
|
|
+ /// # Examples
|
|
|
+ ///
|
|
|
+ /// ```
|
|
|
+ /// use std::ffi::CStr;
|
|
|
+ ///
|
|
|
+ /// let c_str = CStr::from_bytes_with_nul(b"foo\0").unwrap();
|
|
|
+ /// assert_eq!(c_str.to_str(), Ok("foo"));
|
|
|
+ /// ```
|
|
|
+ pub fn to_str(&self) -> Result<&str, str::Utf8Error> {
|
|
|
+ // NB: When CStr is changed to perform the length check in .to_bytes()
|
|
|
+ // instead of in from_ptr(), it may be worth considering if this should
|
|
|
+ // be rewritten to do the UTF-8 check inline with the length calculation
|
|
|
+ // instead of doing it afterwards.
|
|
|
+ str::from_utf8(self.to_bytes())
|
|
|
+ }
|
|
|
+
|
|
|
+ /// Converts a `CStr` into a [`Cow`]`<`[`str`]`>`.
|
|
|
+ ///
|
|
|
+ /// If the contents of the `CStr` are valid UTF-8 data, this
|
|
|
+ /// function will return a [`Cow`]`::`[`Borrowed`]`(`[`&str`]`)`
|
|
|
+ /// with the the corresponding [`&str`] slice. Otherwise, it will
|
|
|
+ /// replace any invalid UTF-8 sequences with
|
|
|
+ /// [`U+FFFD REPLACEMENT CHARACTER`][U+FFFD] and return a
|
|
|
+ /// [`Cow`]`::`[`Owned`]`(`[`String`]`)` with the result.
|
|
|
+ ///
|
|
|
+ /// > **Note**: This method is currently implemented to check for validity
|
|
|
+ /// > after a constant-time cast, but it is planned to alter its definition
|
|
|
+ /// > in the future to perform the length calculation in addition to the
|
|
|
+ /// > UTF-8 check whenever this method is called.
|
|
|
+ ///
|
|
|
+ /// [`Cow`]: ../borrow/enum.Cow.html
|
|
|
+ /// [`Borrowed`]: ../borrow/enum.Cow.html#variant.Borrowed
|
|
|
+ /// [`Owned`]: ../borrow/enum.Cow.html#variant.Owned
|
|
|
+ /// [`str`]: ../primitive.str.html
|
|
|
+ /// [`String`]: ../string/struct.String.html
|
|
|
+ /// [U+FFFD]: ../char/constant.REPLACEMENT_CHARACTER.html
|
|
|
+ ///
|
|
|
+ /// # Examples
|
|
|
+ ///
|
|
|
+ /// Calling `to_string_lossy` on a `CStr` containing valid UTF-8:
|
|
|
+ ///
|
|
|
+ /// ```
|
|
|
+ /// use std::borrow::Cow;
|
|
|
+ /// use std::ffi::CStr;
|
|
|
+ ///
|
|
|
+ /// let c_str = CStr::from_bytes_with_nul(b"Hello World\0").unwrap();
|
|
|
+ /// assert_eq!(c_str.to_string_lossy(), Cow::Borrowed("Hello World"));
|
|
|
+ /// ```
|
|
|
+ ///
|
|
|
+ /// Calling `to_string_lossy` on a `CStr` containing invalid UTF-8:
|
|
|
+ ///
|
|
|
+ /// ```
|
|
|
+ /// use std::borrow::Cow;
|
|
|
+ /// use std::ffi::CStr;
|
|
|
+ ///
|
|
|
+ /// let c_str = CStr::from_bytes_with_nul(b"Hello \xF0\x90\x80World\0").unwrap();
|
|
|
+ /// assert_eq!(
|
|
|
+ /// c_str.to_string_lossy(),
|
|
|
+ /// Cow::Owned(String::from("Hello �World")) as Cow<str>
|
|
|
+ /// );
|
|
|
+ /// ```
|
|
|
+ pub fn to_string_lossy(&self) -> Cow<str> {
|
|
|
+ String::from_utf8_lossy(self.to_bytes())
|
|
|
+ }
|
|
|
+
|
|
|
+ /// Converts a [`Box`]`<CStr>` into a [`CString`] without copying or allocating.
|
|
|
+ ///
|
|
|
+ /// [`Box`]: ../boxed/struct.Box.html
|
|
|
+ /// [`CString`]: struct.CString.html
|
|
|
+ ///
|
|
|
+ /// # Examples
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+ ///
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+ /// ```
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+ /// use std::ffi::CString;
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+ ///
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+ /// let c_string = CString::new(b"foo".to_vec()).unwrap();
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+ /// let boxed = c_string.into_boxed_c_str();
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+ /// assert_eq!(boxed.into_c_string(), CString::new("foo").unwrap());
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+ /// ```
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+ pub fn into_c_string(self: Box<CStr>) -> CString {
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+ let raw = Box::into_raw(self) as *mut [u8];
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+ CString { inner: unsafe { Box::from_raw(raw) } }
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+ }
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+}
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+
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+impl PartialEq for CStr {
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+ fn eq(&self, other: &CStr) -> bool {
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+ self.to_bytes().eq(other.to_bytes())
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+ }
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+}
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+
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+impl Eq for CStr {}
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+
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+impl PartialOrd for CStr {
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+ fn partial_cmp(&self, other: &CStr) -> Option<Ordering> {
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+ self.to_bytes().partial_cmp(&other.to_bytes())
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+ }
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+}
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+
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+impl Ord for CStr {
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+ fn cmp(&self, other: &CStr) -> Ordering {
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+ self.to_bytes().cmp(&other.to_bytes())
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+ }
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+}
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+
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+impl ToOwned for CStr {
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+ type Owned = CString;
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+
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+ fn to_owned(&self) -> CString {
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+ CString { inner: self.to_bytes_with_nul().into() }
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+ }
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+}
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+
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+impl<'a> From<&'a CStr> for CString {
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+ fn from(s: &'a CStr) -> CString {
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+ s.to_owned()
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+ }
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+}
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+
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+impl ops::Index<ops::RangeFull> for CString {
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+ type Output = CStr;
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+
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+ #[inline]
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+ fn index(&self, _index: ops::RangeFull) -> &CStr {
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+ self
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+ }
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+}
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+
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+impl AsRef<CStr> for CStr {
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+ #[inline]
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+ fn as_ref(&self) -> &CStr {
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|
|
+ self
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|
|
+ }
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+}
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+
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|
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+impl AsRef<CStr> for CString {
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+ #[inline]
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|
|
+ fn as_ref(&self) -> &CStr {
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|
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+ self
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|
|
+ }
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+}
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Jeremy Soller