https://github.com/mre/fcat

A 3x faster implementation of cat, using splice
https://github.com/mre/fcat

android cat linux splice unix

Last synced: 5 days ago
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A 3x faster implementation of cat, using splice

• Host: GitHub
• URL: https://github.com/mre/fcat
• Owner: mre
• License: apache-2.0
• Created: 2018-07-31T15:08:31.000Z (over 6 years ago)
• Default Branch: master
• Last Pushed: 2023-05-24T04:58:01.000Z (over 1 year ago)
• Last Synced: 2024-10-22T22:53:29.120Z (12 days ago)
• Topics: android, cat, linux, splice, unix
• Language: Rust
• Homepage: https://endler.dev/2018/fastcat
• Size: 447 KB
• Stars: 268
• Watchers: 10
• Forks: 8
• Open Issues: 8
• Metadata Files:
  • Readme: README.md
  • Funding: .github/FUNDING.yml
  • License: LICENSE-APACHE

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README

        
# 😼 fcat

![Github Actions](https://action-badges.now.sh/mre/fcat?action=test)

![fastcat logo](/fastcat.svg)

`fcat`, short for *fastcat*, is a `cat` implementation in Rust using Linux's `splice` syscall.  

With that little trick, it's **more than three times as fast as the system `cat`** in our benchmarks.  

Read the [announcement here](https://endler.dev/2018/fastcat).

:warning: **This project is currently broken on newer Linux versions (5.9+) because of some changes  

concerning the `splice` system call. (See [here](http://archive.lwn.net:8080/linux-kernel/202105071116.638258236E@keescook/t/) and [here](https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.9).) This can't be fixed unless changes to the kernel get made.**

## Performance

```

cat myfile | pv -r > /dev/null

[1.90GiB/s]

```

```

fcat myfile | pv -r > /dev/null

[5.90GiB/s]

```

## Installation

Note: Only works on Linux.  

(But you can send me a pull request for other operating systems.)

```

cargo install fcat

```

## Usage

```

fcat file1 file2 file3

```

## Project goals

* Be the fastest cat in town.

* Be a drop-in replacement for (POSIX) cat.

## Non-goals

* Provide any additional functionality other than what `cat` provides.  

  If you're looking for a more *beautiful* cat, check out [bat](https://github.com/sharkdp/bat).

## Known issues

If you run `fcat /dev/zero >> myfile`, it will fail with exit code `EINVAL` because, according to the [splice manpage](http://man7.org/linux/man-pages/man2/splice.2.html): "The target file is opened in append mode."

## Trivia

* You probably won't ever need this, but it's a fun little experiment.  

  Still, I wonder why this is not part of e.g. GNU cat...

* What I like the most about the project is the logo.

## License

fcat is licensed under either of

* Apache License, Version 2.0, (LICENSE-APACHE or

  http://www.apache.org/licenses/LICENSE-2.0)

* MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.