30 lines
6.8 KiB
HTML
30 lines
6.8 KiB
HTML
<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Reads the entire contents of a file into a bytes vector."><title>read in tokio::fs - Rust</title><script>if(window.location.protocol!=="file:")document.head.insertAdjacentHTML("beforeend","SourceSerif4-Regular-6b053e98.ttf.woff2,FiraSans-Italic-81dc35de.woff2,FiraSans-Regular-0fe48ade.woff2,FiraSans-MediumItalic-ccf7e434.woff2,FiraSans-Medium-e1aa3f0a.woff2,SourceCodePro-Regular-8badfe75.ttf.woff2,SourceCodePro-Semibold-aa29a496.ttf.woff2".split(",").map(f=>`<link rel="preload" as="font" type="font/woff2"href="../../static.files/${f}">`).join(""))</script><link rel="stylesheet" href="../../static.files/normalize-9960930a.css"><link rel="stylesheet" href="../../static.files/rustdoc-ca0dd0c4.css"><meta name="rustdoc-vars" data-root-path="../../" data-static-root-path="../../static.files/" data-current-crate="tokio" data-themes="" data-resource-suffix="" data-rustdoc-version="1.93.1 (01f6ddf75 2026-02-11) (Arch Linux rust 1:1.93.1-1)" data-channel="1.93.1" data-search-js="search-9e2438ea.js" data-stringdex-js="stringdex-a3946164.js" data-settings-js="settings-c38705f0.js" ><script src="../../static.files/storage-e2aeef58.js"></script><script defer src="sidebar-items.js"></script><script defer src="../../static.files/main-a410ff4d.js"></script><noscript><link rel="stylesheet" href="../../static.files/noscript-263c88ec.css"></noscript><link rel="alternate icon" type="image/png" href="../../static.files/favicon-32x32-eab170b8.png"><link rel="icon" type="image/svg+xml" href="../../static.files/favicon-044be391.svg"></head><body class="rustdoc fn"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><rustdoc-topbar><h2><a href="#">read</a></h2></rustdoc-topbar><nav class="sidebar"><div class="sidebar-crate"><h2><a href="../../tokio/index.html">tokio</a><span class="version">1.49.0</span></h2></div><div class="sidebar-elems"><section id="rustdoc-toc"><h2 class="location"><a href="#">read</a></h2><h3><a href="#">Sections</a></h3><ul class="block top-toc"><li><a href="#errors" title="Errors">Errors</a></li><li><a href="#io_uring-support" title="io_uring support">io_uring support</a></li><li><a href="#examples" title="Examples">Examples</a></li></ul></section><div id="rustdoc-modnav"><h2><a href="index.html">In tokio::<wbr>fs</a></h2></div></div></nav><div class="sidebar-resizer" title="Drag to resize sidebar"></div><main><div class="width-limiter"><section id="main-content" class="content"><div class="main-heading"><div class="rustdoc-breadcrumbs"><a href="../index.html">tokio</a>::<wbr><a href="index.html">fs</a></div><h1>Function <span class="fn">read</span> <button id="copy-path" title="Copy item path to clipboard">Copy item path</button></h1><rustdoc-toolbar></rustdoc-toolbar><span class="sub-heading"><a class="src" href="../../src/tokio/fs/read.rs.html#56-77">Source</a> </span></div><pre class="rust item-decl"><code>pub async fn read(path: impl <a class="trait" href="https://doc.rust-lang.org/1.93.1/core/convert/trait.AsRef.html" title="trait core::convert::AsRef">AsRef</a><<a class="struct" href="https://doc.rust-lang.org/1.93.1/std/path/struct.Path.html" title="struct std::path::Path">Path</a>>) -> <a class="type" href="https://doc.rust-lang.org/1.93.1/std/io/error/type.Result.html" title="type std::io::error::Result">Result</a><<a class="struct" href="https://doc.rust-lang.org/1.93.1/alloc/vec/struct.Vec.html" title="struct alloc::vec::Vec">Vec</a><<a class="primitive" href="https://doc.rust-lang.org/1.93.1/std/primitive.u8.html">u8</a>>></code></pre><details class="toggle top-doc" open><summary class="hideme"><span>Expand description</span></summary><div class="docblock"><p>Reads the entire contents of a file into a bytes vector.</p>
|
|
<p>This is an async version of <a href="https://doc.rust-lang.org/1.93.1/std/fs/fn.read.html" title="fn std::fs::read"><code>std::fs::read</code></a>.</p>
|
|
<p>This is a convenience function for using <a href="struct.File.html#method.open" title="associated function tokio::fs::File::open"><code>File::open</code></a> and <a href="../io/trait.AsyncReadExt.html#method.read_to_end" title="method tokio::io::AsyncReadExt::read_to_end"><code>read_to_end</code></a>
|
|
with fewer imports and without an intermediate variable. It pre-allocates a
|
|
buffer based on the file size when available, so it is generally faster than
|
|
reading into a vector created with <code>Vec::new()</code>.</p>
|
|
<p>This operation is implemented by running the equivalent blocking operation
|
|
on a separate thread pool using <a href="../task/fn.spawn_blocking.html" title="fn tokio::task::spawn_blocking"><code>spawn_blocking</code></a>.</p>
|
|
<h2 id="errors"><a class="doc-anchor" href="#errors">§</a>Errors</h2>
|
|
<p>This function will return an error if <code>path</code> does not already exist.
|
|
Other errors may also be returned according to <a href="struct.OpenOptions.html#method.open" title="method tokio::fs::OpenOptions::open"><code>OpenOptions::open</code></a>.</p>
|
|
<p>It will also return an error if it encounters while reading an error
|
|
of a kind other than <a href="https://doc.rust-lang.org/1.93.1/std/io/error/enum.ErrorKind.html#variant.Interrupted" title="variant std::io::error::ErrorKind::Interrupted"><code>ErrorKind::Interrupted</code></a>.</p>
|
|
<h2 id="io_uring-support"><a class="doc-anchor" href="#io_uring-support">§</a>io_uring support</h2>
|
|
<p>On Linux, you can also use io_uring for executing system calls. To enable
|
|
io_uring, you need to specify the <code>--cfg tokio_unstable</code> flag at compile time,
|
|
enable the io-uring cargo feature, and set the <code>Builder::enable_io_uring</code>
|
|
runtime option.</p>
|
|
<p>Support for io_uring is currently experimental, so its behavior may change
|
|
or it may be removed in future versions.</p>
|
|
<h2 id="examples"><a class="doc-anchor" href="#examples">§</a>Examples</h2>
|
|
<div class="example-wrap"><pre class="rust rust-example-rendered"><code><span class="kw">use </span>tokio::fs;
|
|
<span class="kw">use </span>std::net::SocketAddr;
|
|
|
|
<span class="attr">#[tokio::main]
|
|
</span><span class="kw">async fn </span>main() -> <span class="prelude-ty">Result</span><(), Box<<span class="kw">dyn </span>std::error::Error + <span class="lifetime">'static</span>>> {
|
|
<span class="kw">let </span>contents = fs::read(<span class="string">"address.txt"</span>).<span class="kw">await</span><span class="question-mark">?</span>;
|
|
<span class="kw">let </span>foo: SocketAddr = String::from_utf8_lossy(<span class="kw-2">&</span>contents).parse()<span class="question-mark">?</span>;
|
|
<span class="prelude-val">Ok</span>(())
|
|
}</code></pre></div></div></details></section></div></main></body></html> |