winreg

Rust bindings to MS Windows Registry API. Work in progress.

Current features:

• Basic registry operations:
  • open/create/delete keys
  • load application hive from a file
  • read and write values
  • seamless conversion between REG_* types and rust primitives
    • String and OsString <= REG_SZ, REG_EXPAND_SZ or REG_MULTI_SZ
    • String, &str, OsString, &OsStr => REG_SZ
    • Vec<String>, Vec<OsString> <= REG_MULTI_SZ
    • Vec<String>, Vec<&str>, Vec<OsString>, Vec<&OsStr> => REG_MULTI_SZ
    • u32 <=> REG_DWORD
    • u64 <=> REG_QWORD
• Iteration through key names and through values
• Transactions
• Transacted serialization of rust types into/from registry (only primitives, structures and maps for now)

Usage

Basic usage

# Cargo.toml
[dependencies]
winreg = "0.10"

extern crate winreg;
use std::io;
use std::path::Path;
use winreg::enums::*;
use winreg::RegKey;

fn main() -> io::Result<()> {
    println!("Reading some system info...");
    let hklm = RegKey::predef(HKEY_LOCAL_MACHINE);
    let cur_ver = hklm.open_subkey("SOFTWARE\\Microsoft\\Windows\\CurrentVersion")?;
    let pf: String = cur_ver.get_value("ProgramFilesDir")?;
    let dp: String = cur_ver.get_value("DevicePath")?;
    println!("ProgramFiles = {}\nDevicePath = {}", pf, dp);
    let info = cur_ver.query_info()?;
    println!("info = {:?}", info);
    let mt = info.get_last_write_time_system();
    println!(
        "last_write_time as winapi::um::minwinbase::SYSTEMTIME = {}-{:02}-{:02} {:02}:{:02}:{:02}",
        mt.wYear, mt.wMonth, mt.wDay, mt.wHour, mt.wMinute, mt.wSecond
    );

    // enable `chrono` feature on `winreg` to make this work
    // println!(
    //     "last_write_time as chrono::NaiveDateTime = {}",
    //     info.get_last_write_time_chrono()
    // );

    println!("And now lets write something...");
    let hkcu = RegKey::predef(HKEY_CURRENT_USER);
    let path = Path::new("Software").join("WinregRsExample1");
    let (key, disp) = hkcu.create_subkey(&path)?;

    match disp {
        REG_CREATED_NEW_KEY => println!("A new key has been created"),
        REG_OPENED_EXISTING_KEY => println!("An existing key has been opened"),
    }

    key.set_value("TestSZ", &"written by Rust")?;
    let sz_val: String = key.get_value("TestSZ")?;
    key.delete_value("TestSZ")?;
    println!("TestSZ = {}", sz_val);

    key.set_value("TestMultiSZ", &vec!["written", "by", "Rust"])?;
    let multi_sz_val: Vec<String> = key.get_value("TestMultiSZ")?;
    key.delete_value("TestMultiSZ")?;
    println!("TestMultiSZ = {:?}", multi_sz_val);

    key.set_value("TestDWORD", &1234567890u32)?;
    let dword_val: u32 = key.get_value("TestDWORD")?;
    println!("TestDWORD = {}", dword_val);

    key.set_value("TestQWORD", &1234567891011121314u64)?;
    let qword_val: u64 = key.get_value("TestQWORD")?;
    println!("TestQWORD = {}", qword_val);

    key.create_subkey("sub\\key")?;
    hkcu.delete_subkey_all(&path)?;

    println!("Trying to open nonexistent key...");
    hkcu.open_subkey(&path).unwrap_or_else(|e| match e.kind() {
        io::ErrorKind::NotFound => panic!("Key doesn't exist"),
        io::ErrorKind::PermissionDenied => panic!("Access denied"),
        _ => panic!("{:?}", e),
    });
    Ok(())
}

Iterators

extern crate winreg;
use std::io;
use winreg::RegKey;
use winreg::enums::*;

fn main() -> io::Result<()> {
    println!("File extensions, registered in system:");
    for i in RegKey::predef(HKEY_CLASSES_ROOT)
        .enum_keys().map(|x| x.unwrap())
        .filter(|x| x.starts_with("."))
    {
        println!("{}", i);
    }

    let system = RegKey::predef(HKEY_LOCAL_MACHINE)
        .open_subkey("HARDWARE\\DESCRIPTION\\System")?;
    for (name, value) in system.enum_values().map(|x| x.unwrap()) {
        println!("{} = {:?}", name, value);
    }

    Ok(())
}

Transactions

# Cargo.toml
[dependencies]
winreg = { version = "0.10", features = ["transactions"] }

extern crate winreg;
use std::io;
use winreg::RegKey;
use winreg::enums::*;
use winreg::transaction::Transaction;

fn main() -> io::Result<()> {
    let t = Transaction::new()?;
    let hkcu = RegKey::predef(HKEY_CURRENT_USER);
    let (key, _disp) = hkcu.create_subkey_transacted("Software\\RustTransaction", &t)?;
    key.set_value("TestQWORD", &1234567891011121314u64)?;
    key.set_value("TestDWORD", &1234567890u32)?;

    println!("Commit transaction? [y/N]:");
    let mut input = String::new();
    io::stdin().read_line(&mut input)?;
    input = input.trim_right().to_owned();
    if input == "y" || input == "Y" {
        t.commit()?;
        println!("Transaction committed.");
    }
    else {
        // this is optional, if transaction wasn't committed,
        // it will be rolled back on disposal
        t.rollback()?;

        println!("Transaction wasn't committed, it will be rolled back.");
    }

    Ok(())
}

Serialization

# Cargo.toml
[dependencies]
winreg = { version = "0.10", features = ["serialization-serde"] }
serde = "1"
serde_derive = "1"

#[macro_use]
extern crate serde_derive;
extern crate winreg;
use std::collections::HashMap;
use std::error::Error;
use winreg::enums::*;

#[derive(Debug, Serialize, Deserialize, PartialEq)]
struct Coords {
    x: u32,
    y: u32,
}

#[derive(Debug, Serialize, Deserialize, PartialEq)]
struct Size {
    w: u32,
    h: u32,
}

#[derive(Debug, Serialize, Deserialize, PartialEq)]
struct Rectangle {
    coords: Coords,
    size: Size,
}

#[derive(Debug, Serialize, Deserialize, PartialEq)]
struct Test {
    t_bool: bool,
    t_u8: u8,
    t_u16: u16,
    t_u32: u32,
    t_u64: u64,
    t_usize: usize,
    t_struct: Rectangle,
    t_map: HashMap<String, u32>,
    t_string: String,
    #[serde(rename = "")] // empty name becomes the (Default) value in the registry
    t_char: char,
    t_i8: i8,
    t_i16: i16,
    t_i32: i32,
    t_i64: i64,
    t_isize: isize,
    t_f64: f64,
    t_f32: f32,
}

fn main() -> Result<(), Box<dyn Error>> {
    let hkcu = winreg::RegKey::predef(HKEY_CURRENT_USER);
    let (key, _disp) = hkcu.create_subkey("Software\\RustEncode")?;

    let mut map = HashMap::new();
    map.insert("".to_owned(), 0); // empty name becomes the (Default) value in the registry
    map.insert("v1".to_owned(), 1);
    map.insert("v2".to_owned(), 2);
    map.insert("v3".to_owned(), 3);

    let v1 = Test {
        t_bool: false,
        t_u8: 127,
        t_u16: 32768,
        t_u32: 123_456_789,
        t_u64: 123_456_789_101_112,
        t_usize: 1_234_567_891,
        t_struct: Rectangle {
            coords: Coords { x: 55, y: 77 },
            size: Size { w: 500, h: 300 },
        },
        t_map: map,
        t_string: "test 123!".to_owned(),
        t_char: 'a',
        t_i8: -123,
        t_i16: -2049,
        t_i32: 20100,
        t_i64: -12_345_678_910,
        t_isize: -1_234_567_890,
        t_f64: -0.01,
        t_f32: 3.15,
    };

    key.encode(&v1)?;

    let v2: Test = key.decode()?;
    println!("Decoded {:?}", v2);

    println!("Equal to encoded: {:?}", v1 == v2);
    Ok(())
}

Changelog

0.10.1

• Bump minimal required version of winapi to 0.3.9 (required for load_app_key)
• Reexport REG_PROCESS_APPKEY and use it in the load_app_key example

0.10.0

• Add RegKey::load_app_key() and RegKey::load_app_key_with_flags() (#30)
• Update dev dependency rand to 0.8
• Add Github actions
• Fix some clippy warnings

0.9.0

• Breaking change: OsStr and OsString registry values are not NULL-terminated any more (#34, #42)
• Refactoring: use macros for ToRegValue impls and tests for string values
• Fix bare_trait_objects warning in the doctests
• Add impl ToRegValue for OsString
• Add conversion between REG_MULTI_SZ and vectors of strings (#16)
• Fix: set minimal winapi version to 0.3.7 (earlier versions don't have impl-default and impl-debug features which we use)
• Appveyor now checks the crate against rust-1.31.1 too

0.8.0

• Implement serialization of char and maps
• Implement std::fmt::Display for RegValue
• Make RegKey::{predef,raw_handle,enum_keys,enum_values} functions const
• Give a better error message when compiling on platforms other than Windows (#38)
• Tests are moved from src/lib.rs to tests/reg_key.rs

0.7.0

• Breaking change: remove deprecated Error::description (#28)
• Optimize Iterator::nth() for the Enum* iterators (#29)

0.6.2

• Add RegKey::delete_subkey_with_flags() (#27)

0.6.1

• Add last_write_time field to RegKeyMetadata (returned by RegKey::query_info()) (#25).
• Add get_last_write_time_system() and get_last_write_time_chrono() (under chrono feature) methods to RegKeyMetadata.

0.6.0

• Breaking change: create_subkey, create_subkey_with_flags, create_subkey_transacted and create_subkey_transacted_with_flags now return a tuple which contains the subkey and its disposition which can be REG_CREATED_NEW_KEY or REG_OPENED_EXISTING_KEY (#21).
• Examples fixed to not use unwrap according to Rust API guidelines.

0.5.1

• Reexport HKEY (#15).
• Add raw_handle method (#18).

0.5.0

• Breaking change: open_subkey now opens a key with readonly permissions. Use create_subkey or open_subkey_with_flags to open with read-write permissins.
• Breaking change: features transactions and serialization-serde are now disabled by default.
• Breaking change: serialization now uses serde instead of rustc-serialize.
• winapi updated to 0.3.
• Documentation fixes (#14)

0.4.0

• Make transactions and serialization otional features
• Update dependensies + minor fixes (#12)

0.3.5

• Implement FromRegValue for OsString and ToRegValue for OsStr (#8)
• Minor fixes

0.3.4

• Add copy_tree method to RegKey
• Now checked with rust-clippy
  • no more unwraps
  • replaced to_string with to_owned
• Fix: reading strings longer than 2048 characters (#6)

0.3.3

• Fix: now able to read values longer than 2048 bytes (#3)

0.3.2

• Fix: FromRegValue trait now requires Sized (fixes build with rust 1.4)

0.3.1

• Fix: bump winapi version to fix build

0.3.0

• Add transactions support and make serialization transacted
• Breaking change: use std::io::{Error,Result} instead of own RegError and RegResult