cargo add anyhow

// ---- Без Anyhow
fn string_error() -> Result<(), String> {
    Ok(())
}
fn io_error() -> Result<(), std::io::Error> {
    Ok(())
}
fn any_error() -> Result<(), Box<dyn Error>> {
    string_error()?;
    io_error()?;
    Ok(())
}
// ---- С Anyhow:
use anyhow::Result;

fn string_error() -> Result<()> {
    Ok(())
}
fn io_error() -> Result<()> {
    Ok(())
}
fn any_error() -> Result<()> {
    string_error()?;
    io_error()?;
    Ok(())
}

use anyhow::{Context, Result};

fn read_config_file(path: &str) -> Result<String> {
    std::fs::read_to_string(path).with_context(|| format!("Failed to read file {}", path))
}

fn main() -> Result<()> {
    let config_content = read_config_file("conf.txt")?;

    println!("Config content:\n{:?}", config_content);

    Ok(())
}

use base64::{self, engine, Engine};

fn decode() -> Result<(), Box<dyn std::error::Error>> {
    let input = std::fs::read_to_string("input")?;
    for line in input.lines() {
        let bytes = engine::general_purpose::STANDARD.decode(line)?;
        println!("{}", String::from_utf8(bytes)?);
    }
    Ok(())
}

use anyhow::Context;
use base64::{self, engine, Engine};

fn decode() -> Result<(), anyhow::Error> {
    let input = std::fs::read_to_string("input")
    .context("Failed to read file")?; // контекст 1
    for line in input.lines() {
        let bytes = engine::general_purpose::STANDARD
            .decode(line)
            .context("Failed to decode the input")?; // контекст 2
        println!(
            "{}",
            String::from_utf8(bytes)
            .context("Failed to cenvert bytes")? // контекст 3
        );
    }
    Ok(())

// map_err — нужно явно создавать anyhow::Error
.map_err(|e| anyhow::anyhow!("ошибка: {}", e))

// context — просто добавляет пояснение
.context("ошибка")?

// context с замыканием — форматирование только при ошибке
let content = std::fs::read_to_string(path)
    .with_context(|| format!("не удалось прочитать файл {}", path))?;

// map_err — форматирование всегда, даже при успехе
let content = std::fs::read_to_string(path)
    .map_err(|e| anyhow::anyhow!("не удалось прочитать файл {}", path))?;

cargo add clap -F derive

use clap::Parser;

#[derive(Parser, Debug)]
struct Args {
    arg1: String,
    arg2: usize,
}

fn main() {
    let args = Args::parse();
    println!("{:?}", args)
}

use clap::Parser;

#[derive(Parser, Debug)]
#[command(author = "Author Name", version, about)]
/// A very simple CLI parser
struct Args {
    /// Text argument option
    arg1: String,
    /// Number argument option
    arg2: usize,
}

fn main() {
    let args = Args::parse();
    println!("{:?}", args)
}

<..>
struct Args {
    #[arg(short = 'a', long)]
    /// Text argument option
    arg1: String,
    
    #[arg(short = 'A', long)]
    /// Number argument option
    arg2: usize,
}
<..>

struct Args {
    #[arg(short = 'a', long)]
    /// Text argument option
    arg1: String,
    
    #[arg(short = 'A', long)]
    /// Number argument option
    arg2: Option<usize>,
}

struct Args {
    #[arg(short = 'a', long)]
    /// Text argument option
    arg1: String,
    
    #[arg(default_value_t=usize::MAX, short = 'A', long)]
    /// Number argument option
    arg2: usize,
}

use clap::Parser;

#[derive(Parser, Debug)]
#[command(author = "Author Name", version, about)]
/// A very simple CLI parser
struct Args {
    #[arg(value_parser = validate_argument_name, short = 'a', long)]
    /// Text argument option
    arg1: String,
    #[arg(default_value_t=usize::MAX, short = 'A', long)]
    /// Number argument option
    arg2: usize,
}

fn validate_argument_name(name: &str) -> Result<String, String> {
    if name.trim().len() != name.len() {
        Err(String::from(
            "строка не должна начинаться или заканчиваться пробелами",
        ))
    } else {
        Ok(name.to_string())
    }
}

fn main() {
    let args = Args::parse();
    println!("{:?}", args)
}

    let output = Command::new("cat")
        .arg("/etc/issue")
        .output()
        .with_context(|| "ls command failed")?;

    println!("{}", output.status);
    println!("{}", String::from_utf8_lossy(&output.stdout));
    println!("{}", String::from_utf8_lossy(&output.stderr));

    let mut child = Command::new("cat") // команда
        .stdin(Stdio::piped())
        .stdout(Stdio::piped())
        .spawn()?;

    let stdin = child.stdin.as_mut()?;
    stdin.write_all(b"Hello Rust!\n")?; // текст к команде, /n обязателен
    let output = child.wait_with_output()?;
    
    for i in output.stdout.iter() { // цикл на случай многострочного вывода
        print!("{}", *i as char);
    }
    Ok(())

rustup install nightly
rustup default nightly

#![feature(anonymous_pipe)] // только в Rust Nightly
use std::pipe

let text = "| grep file".as_bytes();

// Запускаем саму команду
let child = Command::new("ls")
    .arg("/Users/test")
    .stdin({
        // Нельзя отправить просто строку в команду
        // Нужно создать файловый дескриптор (как в обычном stdin "pipe")
        // Поэтому создаём пару pipes тут
        let (reader, mut writer) = std::pipe::pipe().unwrap();

        // Пишем строку в одну pipe
        writer.write_all(text).unwrap();

        // далее превращаем вторую для передачи в команду сразу при spawn. 
        Stdio::from(reader)
    })
    .spawn()?;

use itertools::Itertools;

let text = "Hello world";
let text_sorted = text.chars().sorted().rev().collect::<String>();
// rev() - Iterate the iterable in reverse
   
println!("Text: {}, Sorted Text: {}", text, text_sorted); 
// Text: Hello world, Sorted Text: wroollledH 

use itertools::Itertools;

let number_list = [1,12,3,1,5,2,7,8,7,8,2,3,12,7,7];
let mode = number_list.iter().counts(); // Itertools::counts() 
// возвращает HashmapHashMap<char, usize>, 
// где ключи взяты из массива, значения - частота
for (key, value) in &mode {  
    println!("Число {key} встречается {value} раз");  
 } 

let mut number_count: HashMap<u32, u32> = HashMap::new();
for c in number_list {
  *number_count.entry(c).or_insert(0) += 1; 
  }

println!("{:?}",number_list.iter().duplicates_by(|x| *x)
.collect::<Vec<&u32>>()
// [2, 3, 6]

println!("{:?}", number_list.iter().duplicates_by(|x| *x).count());

use rand::Rng;

fn main() {
let secret_of_type = rand::rng().random::<u32>();
let secret = rand::rng().random_range(1..=100);

println!("Random nuber of type u32: {secret_of_type}");
println!("Random nuber from 1 to 100: {}", secret); }

cargo add regex

.             any character except new line (includes new line with s flag)
\d            digit (\p{Nd})
\D            not digit
\pX           Unicode character class identified by a one-letter name
\p{Greek}     Unicode character class (general category or script)
\PX           Negated Unicode character class identified by a one-letter name
\P{Greek}     negated Unicode character class (general category or script)

[xyz]         A character class matching either x, y or z (union).
[^xyz]        A character class matching any character except x, y and z.
[a-z]         A character class matching any character in range a-z.
[[:alpha:]]   ASCII character class ([A-Za-z])
[[:^alpha:]]  Negated ASCII character class ([^A-Za-z])
[x[^xyz]]     Nested/grouping character class (matching any character except y and z)
[a-y&&xyz]    Intersection (matching x or y)
[0-9&&[^4]]   Subtraction using intersection and negation (matching 0-9 except 4)
[0-9--4]      Direct subtraction (matching 0-9 except 4)
[a-g~~b-h]    Symmetric difference (matching `a` and `h` only)
[\[\]]        Escaping in character classes (matching [ or ])

xy    concatenation (x followed by y)
x|y   alternation (x or y, prefer x)

x*        zero or more of x (greedy)
x+        one or more of x (greedy)
x?        zero or one of x (greedy)
x*?       zero or more of x (ungreedy/lazy)
x+?       one or more of x (ungreedy/lazy)
x??       zero or one of x (ungreedy/lazy)
x{n,m}    at least n x and at most m x (greedy)
x{n,}     at least n x (greedy)
x{n}      exactly n x
x{n,m}?   at least n x and at most m x (ungreedy/lazy)
x{n,}?    at least n x (ungreedy/lazy)
x{n}?     exactly n x

^     the beginning of text (or start-of-line with multi-line mode)
$     the end of text (or end-of-line with multi-line mode)
\A    only the beginning of text (even with multi-line mode enabled)
\z    only the end of text (even with multi-line mode enabled)
\b    a Unicode word boundary (\w on one side and \W, \A, or \z on other)
\B    not a Unicode word boundary

(exp)          numbered capture group (indexed by opening parenthesis)
(?P<name>exp)  named (also numbered) capture group (names must be alpha-numeric)
(?<name>exp)   named (also numbered) capture group (names must be alpha-numeric)
(?:exp)        non-capturing group
(?flags)       set flags within current group
(?flags:exp)   set flags for exp (non-capturing)

\*          literal *, works for any punctuation character: \.+*?()|[]{}^$
\a          bell (\x07)
\f          form feed (\x0C)
\t          horizontal tab
\n          new line
\r          carriage return
\v          vertical tab (\x0B)
\123        octal character code (up to three digits) (when enabled)
\x7F        hex character code (exactly two digits)
\x{10FFFF}  any hex character code corresponding to a Unicode code point
\u007F      hex character code (exactly four digits)
\u{7F}      any hex character code corresponding to a Unicode code point
\U0000007F  hex character code (exactly eight digits)
\U{7F}      any hex character code corresponding to a Unicode code point

[[:alnum:]]    alphanumeric ([0-9A-Za-z])
[[:alpha:]]    alphabetic ([A-Za-z])
[[:ascii:]]    ASCII ([\x00-\x7F])
[[:blank:]]    blank ([\t ])
[[:cntrl:]]    control ([\x00-\x1F\x7F])
[[:digit:]]    digits ([0-9])
[[:graph:]]    graphical ([!-~])
[[:lower:]]    lower case ([a-z])
[[:print:]]    printable ([ -~])
[[:punct:]]    punctuation ([!-/:-@\[-`{-~])
[[:space:]]    whitespace ([\t\n\v\f\r ])
[[:upper:]]    upper case ([A-Z])
[[:word:]]     word characters ([0-9A-Za-z_])
[[:xdigit:]]   hex digit ([0-9A-Fa-f])

use regex::Regex;
fn main() -> Result<(), Box<dyn std::error::Error>> {
    let input = "hello, world!";
    let pattern = Regex::new(r"hello, (world|universe)!")?;
    
    let is_match = pattern.is_match(input);
    println!("Is match: {}", is_match); // true
    Ok(())
}

    let pattern = regex::Regex::new(r"hello, (world|universe)!")?;
    let input = "hello, world!";
    let first_match = pattern.find(input);

    println!("First match: {}", first_match.unwrap().as_str());

    let pattern = regex::Regex::new(r"hello, (world|universe)!")?;
    let input = "hello, world! hello, universe!";
    let matches: Vec<_> = pattern.find_iter(input).collect(); // find_iter()
    matches.iter().for_each(|i| println!("{}", i.as_str()));
    // matches = Vec<match> и содержит все совпадения

cargo add serde -F derive
cargo add serde_json

use serde::{Deserialize, Serialize};

#[derive(PartialEq, Debug, Clone, Serialize, Deserialize)]
pub enum LoginRole {
    Admin,
    User,
}

#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct User {
    pub username: String,
    pub password: String,
    pub role: LoginRole,
}

pub fn get_default_users() -> HashMap<String, User> {
    let mut users = HashMap::new();
    users.insert(
        "admin".to_string(),
        User::new("admin", "password", LoginRole::Admin),
    );
    users.insert(
        "bob".to_string(),
        User::new("bob", "password", LoginRole::User),
    );
    users
}

pub fn get_users() -> HashMap<String, User> {
    let users_path = Path::new("users.json");
    if users_path.exists() {
        // Load the file!
        let users_json = std::fs::read_to_string(users_path).unwrap();
        let users: HashMap<String, User> = serde_json::from_str(&users_json).unwrap();
        users
    } else {
        // Create a file and return it
        let users = get_default_users();
        let users_json = serde_json::to_string(&users).unwrap();
        std::fs::write(users_path, users_json).unwrap();
        users
    }

cargo add sysinfo

use std::process;                   // номер процесса PID вывести
use sysinfo::{RefreshKind, System};

fn main() {
    let _sys = System::new_with_specifics(RefreshKind::nothing());
    let pid = process::id();
    println!("System name:             {:?}", System::name());
    println!("System kernel version:   {:?}", System::kernel_version());
    println!("System OS version:       {:?}", System::os_version());
    println!("System host name:        {:?}", System::host_name());
    println!("Process ID:              {}", pid);
}

#[derive(thiserror::Error)]

use thiserror::Error;
#[derive(Error, Debug)]
pub enum MyLibError {
    #[error("Network failed: {0}")]
    Network(String),
    #[error("Invalid user ID: {id}")]
    InvalidUserId { id: u32 },
    #[error("File not found")]
    NotFound,
    #[error("IO error: {0}")]
    Io(#[from] std::io::Error),
}

pub fn get_user(id: u32) -> Result<String, MyLibError> {
    if id == 0 {
        return Err(MyLibError::InvalidUserId { id });
    }
    std::fs::read_to_string("config.txt")?; // автоконвертирует тип ошибки
    Ok(format!("User {}", id))
}

use your_lib::{get_user, MyLibError};

match get_user(0) {
    Ok(name) => println!("Got {name}"),
    Err(MyLibError::InvalidUserId { id }) => {
        println!("You gave ID {id}, but that's invalid!");
        // обработать конкретно
    }
    Err(MyLibError::NotFound) => {
        println!("File missing, creating new one...");
        // создать файл
    }
    Err(e) => {
        println!("Other error: {e}");
    }
}

// Библиотека (image_loader.rs)
#[derive(thiserror::Error, Debug)]
pub enum ImageError {
    #[error("File too large: {size} bytes")]
    TooLarge { size: u64 },
    #[error("Unsupported format: {format}")]
    BadFormat { format: String },
    #[error("Corrupted data")]
    Corrupted,
}

pub fn load_image(path: &str) -> Result<Vec<u8>, ImageError> {
    // ...
}

// Кто-то используем библиотеку:
match image_loader::load_image("photo.png") {
    Ok(data) => render(data),
    Err(ImageError::TooLarge { size }) => 
        println!("Your image is {size} bytes, max is 10MB"),
    Err(ImageError::BadFormat { format }) => 
        println!("Sorry, we don't support {format} files"),
    Err(ImageError::Corrupted) => 
        println!("The image is broken"),
}

cargo add tracing
cargo add tracing-subscriber -F json

use tracing::info;

fn main() {
    // Установка глобального сборщика по конфигурации
    tracing_subscriber::fmt::init();

    let number_of_yaks = 3;

    // новое событие, вне промежутков
    info!(number_of_yaks, "preparing to shave yaks");
}

fn setup_tracing() {
    let subscriber = tracing_subscriber::fmt()
        .json() // нужно cargo add tracing-subscriber -F json
        .with_max_level(tracing::Level::TRACE) // МАХ уровень логирования
        .compact() // компактный лог
        .with_file(true) // показывать файл-исходник
        .with_line_number(true) // показать номера строк кода
        .with_thread_ids(true) // показать ID потока с событием
        .with_target(false) // не показывать цель (модуль) события
        .finish();

    tracing::subscriber::set_global_default(subscriber).unwrap();

    tracing::info!("Starting up");
    tracing::warn!("Are you sure this is a good idea?");
    tracing::error!("This is an error!");
}

use tracing::{instrument, warn};

#[instrument]
fn sync_tracing() {
    warn!("event 1");
    sync_tracing_sub();
}

#[instrument]
fn sync_tracing_sub() {
    warn!("event 2");
}

fn main() {
    setup_tracing();
    sync_tracing();
}

use tracing_subscriber::fmt::format::FmtSpan;

#[tracing::instrument] // инструмент следит за временем работы
async fn hello() {
    tokio::time::sleep(tokio::time::Duration::from_secs(1)).await;
}

#[tokio::main] // cargo add tokio -F time,macros,rt-multi-thread
async fn main() -> anyhow::Result<()> {
    let subscriber = tracing_subscriber::fmt()
        .json()
        .compact()
        .with_file(true)
        .with_line_number(true)
        .with_thread_ids(true)
        .with_target(false)
        .with_span_events(FmtSpan::ENTER | FmtSpan::CLOSE) // вход и выход
        .finish();                                   // потока отслеживать

    tracing::subscriber::set_global_default(subscriber).unwrap();

    hello().await;
    Ok(())
}

2024-12-24T14:30:17.378906Z  INFO ThreadId(01) hello: src/main.rs:3: {"message":"enter"} {}
2024-12-24T14:30:18.383596Z  INFO ThreadId(01) hello: src/main.rs:3: {"message":"enter"} {}
2024-12-24T14:30:18.383653Z  INFO ThreadId(01) hello: src/main.rs:3: {"message":"enter"} {}
2024-12-24T14:30:18.383675Z  INFO ThreadId(01) hello: src/main.rs:3: {"message":"close","time.busy":"179µs","time.idle":"1.00s"} {}

cargo add tracing-appender

use tracing::{instrument, warn};

// тянем std::io::Write признак в режиме неблокирования
use tracing_subscriber::fmt::writer::MakeWriterExt; 

fn setup_tracing() {
    // инициализация файла с дозаписью
    let logfile = tracing_appender::rolling::hourly("/some/directory", "app-log");
    // уровень записи при логировании = INFO
    let stdout = std::io::stdout.with_max_level(tracing::Level::INFO);

    let subscriber = tracing_subscriber::fmt()
        .with_max_level(tracing::Level::TRACE)
        .json()
        .compact()
        .with_file(true)
        .with_line_number(true)
        .with_thread_ids(true)
        .with_target(false)
        .with_writer(stdout.and(logfile)) // обязательно указать запись тут
        .finish();                        // в файл и в stdout консоль
    tracing::subscriber::set_global_default(subscriber).unwrap();
}

#[instrument]
fn sync_tracing() {
    warn!("event 1");
    sync_tracing_sub();
}

#[instrument]
fn sync_tracing_sub() {
    warn!("event 2");
}

fn main() {
    setup_tracing();
    sync_tracing();
}

[workspace]
members = [ "authentication", "common-log","hello_world", "login"]

[dependencies]
tracing.workspace = true
tracing-appender.workspace = true
tracing-subscriber.workspace = true

[workspace.dependencies]
tracing = "0.1.41"
tracing-appender = "0.2.3"
tracing-subscriber = { version = "0.3.19", features = ["json"] }

[dependencies]
tracing = { workspace = true }
tracing-appender = { workspace = true }
tracing-subscriber = { workspace = true }

use tracing_subscriber::fmt::writer::MakeWriterExt;

pub fn setup_tracing() {
    let logfile = tracing_appender::rolling::hourly("./log", "auth");
    let stdout = std::io::stdout.with_max_level(tracing::Level::INFO);
    let subscriber = tracing_subscriber::fmt()
        .json()
        .with_max_level(tracing::Level::TRACE)
        .compact()
        .with_file(true)
        .with_line_number(true)
        .with_thread_ids(true)
        .with_target(false)
        .with_writer(stdout.and(logfile))
        .finish();
    tracing::subscriber::set_global_default(subscriber).expect("setting default subscriber failed");

    // Проверка разных сообщений логгера:
    //tracing::info!("INFO TEXT");
    //tracing::warn!("WARNING TEXT");
    //tracing::error!("ERROR TEXT");
    //tracing::debug!("DEBUG TEXT");
}

#[cfg(test)]
mod tests {
    //use super::*;
}

[dependencies]
common-logging = { path = "../common-logging" }
tracing = { workspace = true }
tracing-appender = { workspace = true }
tracing-subscriber = { workspace = true }

use tracing::{debug, error, info, warn};
pub fn greet_user(name: &str) -> String {
    info!("Library _greet_user_ function called"); // вызов логгера
    format!("Hello {name}")
}

[dependencies]
common-log = { path = "../common-log" }
tracing = { workspace = true }
tracing-appender = { workspace = true }
tracing-subscriber = { workspace = true }

use common_log::setup_tracing;
use tracing::{debug, error, info, warn};

fn main() {
    setup_tracing(); // инициализация логгера из библиотеки common-log
    info!("Logger initialized. App started."); // вызов логгера
}

#[cfg(test)]
mod tests {
    use super::*;
    use common_logging::setup_tracking;

    #[test]
    fn test_something() {
        init_test_logger();
        // ваш тест
    }
}

# Установка уровня логирования
RUST_LOG=debug cargo run
RUST_LOG=my_library=debug,info cargo run

# Для конкретного крейта
RUST_LOG=my_library=debug cargo run