magical_rs

A zero-dependency, no_std-friendly Rust crate that detects file types with surgical precision by matching magic bytes at exact offsets — including deep-offset formats like ISO and TAR. Built for speed, safety, and extensibility.

Table of Contents:

• magical_rs
  • Table of Contents:
  • Level of use
  • Supported File Types
  • License

Level of use

Level 1, uses built-in file detection via signature:

• At this level, you will use the magical_rs built-in API, which supports detecting ~50 file types via signatures.

• List of currently supported file types here

• By the way, you can contribute new file signatures here

• Examples:

•   use magical_rs::magical::bytes_read::{read_file_header, with_bytes_read};
    use magical_rs::magical::magic::FileKind;
  
    let max_byte_read = with_bytes_read();
  
    let bytes = read_file_header("img/2.iso", max_byte_read).unwrap();
  
    match FileKind::match_types(&bytes) {
        Some(k) => println!("{k:?}"),
        None => println!("Could not detect ISO file."),
    }
  

• More examples of level 1 can be found here

Level 2, untilimited compiler-time customization with infinite function pointers:

• At this level, you can customize file signatures, offsets, and more.

• Here, you can also use function pointers for complex logic. In theory, you can do almost anything at compiler-time. And thanks to that, you can detect any file type you want.

• Also, supports the use of infinite function pointers at once. And function pointers have macros with syntax-sugar supports at well.

• Examples:

• use magical_rs::{any_matches, magic_custom, match_custom};
  
  #[derive(Clone, Copy, PartialEq, Eq, Debug)]
  enum FileKind {
    Shoujo,
    UnknownFallback,
  }
  
  fn is_shoujo(bytes: &[u8]) -> bool {
      bytes.starts_with(b"Magic!")
  }
  
  fn is_not_shoujo(bytes: &[u8]) -> bool {
      !bytes.starts_with(b"Magic!")
  }
  
  pub fn magic_custom_any() {
      let rule = magic_custom! (
          signatures: [],
          offsets: [0],
          max_bytes_read: 2451,
          kind: FileKind::Shoujo,
          rules: any_matches!(is_shoujo, is_not_shoujo)
      );
  
      let result = match_custom! (
          bytes: b"Magic!",
          rules: [rule],
          fallback: FileKind::UnknownFallback
      );
  
      assert_eq!(result, FileKind::Shoujo);
      assert_ne!(result, FileKind::UnknownFallback);
  }
  

• There are many ways to implement it, and you can find them here

Level 1 & 2 both support no_std.

Level 3, custom run-time file detection with infinite logic

• At this level, you can customize the runtime logic. You can do anything. You can detect any type of file, even if it changes at run-time. You can emit AI, send requests to the Open-AI API, even spawn processes. The only limit is your imagination.

• So, you need to unlock this feature by:

• cargo add magical_rs --features magical_dyn
  

• Examples:

• use magical_rs::magical::dyn_magic::DynMagicCustom;
  
  fn my_detect_rule() -> impl Fn(&[u8]) -> bool {
      let require_bytes = b"MagicalGirl";
  
      |bytes: &[u8]| bytes.starts_with(require_bytes) && bytes.len() == require_bytes.len()
  }
  
  fn detect_custom_file(file_bytes: &'static [u8]) -> bool {
  
      let detect_fn = my_detect_rule();
      let rule = DynMagicCustom::new(detect_fn, String::from("Is Mahou Shoujo Detect."), 32);
  
      let kind = rule.kind_downcast_ref::<String>();
      
      match kind {
          Some(k) => println!("{k}"), /* Is Mahou Shoujo Detect. */
          None => println!("Kind not found."),
      }
      rule.matches(file_bytes)
  }
  
  

• Many examples of use can be found here

• Warning: Use only if you really know what you are doing.

Level 4, Configure, code rules, deploy endlessly and without limits in asynchronous.

• Here you can design file detection rules with any logic no matter how complex in asynchronous environment. There are no specific limitations other than your own skill level. Only use it when you know what you're doing, and only use it when you really need to identify files in an asynchronous environment. If you are new to Rust or unsure, stop here and just use level 2 below. You're not as good as you think. Unless you really understand what the hell you're doing. And if you really know what you're doing, congratulations! You have one of the most powerful file recognition systems in the Rust ecosystem.

• Don't blame me and other maintainers for your ignorance if something bad happends because I warned you in advance.

• You need run this command bellow enable the feature:

• cargo add magical_rs --features magical_async_dyn
  

• Examples:

• use async_std::task;
  use magical_rs::magical::async_dyn_magic::AsyncDynMagic;
  use magical_rs::magical::async_dyn_magic::match_dyn_types_as;
  use std::time::Duration;
  
  async fn magic_async_detect() {
      let func_detect = |bytes: &[u8]| {
          let owned_bytes = bytes.to_vec();
  
          Box::pin(async move {
              println!("Rest for 1 second");
  
              task::sleep(Duration::from_millis(1000)).await;
              owned_bytes.starts_with(b"Magical")
          })
      };
  
      let rule = AsyncDynMagic::new(func_detect, "Magical_File", 128);
      let rules = vec![rule];
  
      let result = match_dyn_types_as::<&str>(b"Magical", &rules).await;
      match result {
          Some(r) => println!("Magical File Detect: {r}"),
          None => println!("Magical File Not Found"),
      }
  }
  

• There are many instructions that can be found at here

Supported File Types

License

• magical_rs is licensed under the GNU General Public License v3.0. See here