在Ubuntu上安装rust

查看rustup安装包信息（可选）

$ snap info rustup
name:      rustup
summary:   "EXPERIMENTAL: The Rust Language installer"
publisher: Daniel Silverstone (dsilvers)
store-url: https://snapcraft.io/rustup
contact:   [email protected]
license:   Apache-2.0 OR MIT
description: |
  **NOTA BENE:** _This is an experimental, unofficial, snap and should not be relied on._
  
  Rustup is the Rust Language's installer and primary front-end.  You probably
  want this if you want to develop anything written in Rust.
  
  Please note, this snap is experimental and may be yanked without notice
  if this experiment proves to be a bad idea.
snap-id: tO4cnls38mXDXJiA0U72G7eCyrCAMweL
channels:
  latest/stable:    1.24.3 2021-06-22 (1027) 4MB classic
  latest/candidate: ↑                            
  latest/beta:      1.25.0 2022-06-13 (1407) 5MB classic
  latest/edge:      1.24.3 2022-07-11 (1425) 5MB classic

安装rustup

$ sudo snap install rustup
[sudo] password for user: 
error: This revision of snap "rustup" was published using classic confinement and thus may perform
       arbitrary system changes outside of the security sandbox that snaps are usually confined to,
       which may put your system at risk.

       If you understand and want to proceed repeat the command including --classic.

直接安装，有上述风险提示，需要在安装命令中增加–classic参数来安装。

$ sudo snap install rustup --classic
Download snap "core18"(2667) from channel "stable"40%  323kB/s 1m48s
rustup 1.24.3 from Daniel Silverstone (dsilvers) installed

安装rustc

安装前，执行rustc --version命令，显示找不到。

$ rustc --version
error: no override and no default toolchain set

安装stable版本

$ rustup install stable
info: syncing channel updates for'stable-x86_64-unknown-linux-gnu'
info: latest update on 2023-01-10, rust version 1.66.1 (90743e729 2023-01-10)
info: downloading component 'cargo'
info: downloading component 'clippy'
info: downloading component 'rust-docs'19.1 MiB /  19.1 MiB (100 %)8.9 MiB/s in  1s ETA:  0s
info: downloading component 'rust-std'30.0 MiB /  30.0 MiB (100 %)16.1 MiB/s in  1s ETA:  0s
info: downloading component 'rustc'67.4 MiB /  67.4 MiB (100 %)12.1 MiB/s in  5s ETA:  0s
info: downloading component 'rustfmt'
info: installing component 'cargo'
info: installing component 'clippy'
info: installing component 'rust-docs'19.1 MiB /  19.1 MiB (100 %)1.6 MiB/s in 10s ETA:  0s 
info: installing component 'rust-std'30.0 MiB /  30.0 MiB (100 %)3.3 MiB/s in  7s ETA:  0s
info: installing component 'rustc'67.4 MiB /  67.4 MiB (100 %)4.4 MiB/s in 16s ETA:  0s
info: installing component 'rustfmt'

  stable-x86_64-unknown-linux-gnu installed - rustc 1.66.1 (90743e729 2023-01-10)

info: default toolchain set to 'stable-x86_64-unknown-linux-gnu'

安装完成后进行确认

$ rustc --version
rustc 1.66.1 (90743e729 2023-01-10)

$ rustup default
stable-x86_64-unknown-linux-gnu (default)

cargo初体验

创建hello工程

创建名为“hello”的工程，名称可以任选。
在命令执行的目录下，创建以工程名（hello）命名的目录，其中包含rust项目默认的目录结构。

$ cargo new hello
     Created binary (application)`hello` package

创建完成后，查看自动生成文件。

$ find hello/
hello/
hello/Cargo.toml
hello/src
hello/src/main.rs

查看main.rs文件内容，默认的一个hello world。

//main.rs fnmain(){println!("Hello, world!");}

编译、运行

编译+运行

在hello目录下，直接执行cargo run，后面不跟项目名称。
自动编译，并运行，显示执行结果。

$ cargo run
   Compiling hello v0.1.0 (/home/user/source/rust/myrust/hello)
    Finished dev [unoptimized + debuginfo] target(s)in0.67s
     Running `target/debug/hello`
Hello, world!

也可以在cargo run后面跟上项目名称。
注意，再次编译耗时为0，因为检测到已生成的目标文件和可执行文件，没有再次编译。

$ cargo run hello
    Finished dev [unoptimized + debuginfo] target(s)in0.00s
     Running `target/debug/hello hello`
Hello, world!

cargo编译自动生成的文件

其中可执行文件为./target/debug/hello

$ find.
./target
./target/debug
./target/debug/hello
./target/debug/deps
./target/debug/deps/hello-274bceb238a71d2c
./target/debug/deps/hello-274bceb238a71d2c.d
./target/debug/.cargo-lock
./target/debug/hello.d
./target/debug/examples
./target/debug/incremental
./target/debug/incremental/hello-1mywrsfxa307p
./target/debug/incremental/hello-1mywrsfxa307p/s-ghgnder5d2-atwot6-1rt7qa06ycrsb
./target/debug/incremental/hello-1mywrsfxa307p/s-ghgnder5d2-atwot6-1rt7qa06ycrsb/1k6fmvbj4kgxmvo.o
./target/debug/incremental/hello-1mywrsfxa307p/s-ghgnder5d2-atwot6-1rt7qa06ycrsb/11gozpvmuuvnuax0.o
./target/debug/incremental/hello-1mywrsfxa307p/s-ghgnder5d2-atwot6-1rt7qa06ycrsb/5a4b3go9tpkabteb.o
./target/debug/incremental/hello-1mywrsfxa307p/s-ghgnder5d2-atwot6-1rt7qa06ycrsb/work-products.bin
./target/debug/incremental/hello-1mywrsfxa307p/s-ghgnder5d2-atwot6-1rt7qa06ycrsb/42ng4k24mutpcm07.o
./target/debug/incremental/hello-1mywrsfxa307p/s-ghgnder5d2-atwot6-1rt7qa06ycrsb/f4rryg4sswprfky.o
./target/debug/incremental/hello-1mywrsfxa307p/s-ghgnder5d2-atwot6-1rt7qa06ycrsb/dep-graph.bin
./target/debug/incremental/hello-1mywrsfxa307p/s-ghgnder5d2-atwot6-1rt7qa06ycrsb/35wjyzzyjx18spd.o
./target/debug/incremental/hello-1mywrsfxa307p/s-ghgnder5d2-atwot6-1rt7qa06ycrsb/query-cache.bin
./target/debug/incremental/hello-1mywrsfxa307p/s-ghgnder5d2-atwot6.lock
./target/debug/.fingerprint
./target/debug/.fingerprint/hello-274bceb238a71d2c
./target/debug/.fingerprint/hello-274bceb238a71d2c/invoked.timestamp
./target/debug/.fingerprint/hello-274bceb238a71d2c/bin-hello
./target/debug/.fingerprint/hello-274bceb238a71d2c/dep-bin-hello
./target/debug/.fingerprint/hello-274bceb238a71d2c/bin-hello.json
./target/debug/build
./target/.rustc_info.json
./target/CACHEDIR.TAG
./Cargo.lock
./Cargo.toml
./src
./src/main.rs

单独执行可执行文件

$ cd target/debug/
$ l
build/  deps/  examples/  hello*  hello.d  incremental/
$ ./hello 
Hello, world!

用rustc单独编译

$ cd src/
$ rustc main.rs 
$ ./main 
Hello, world!