fd/README.md

# fd
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*fd* is a simple, fast and user-friendly alternative to
[*find*](https://www.gnu.org/software/findutils/).

While it does not seek to mirror all of *find*'s powerful functionality, it provides sensible
(opinionated) defaults for [80%](https://en.wikipedia.org/wiki/Pareto_principle) of the use cases.

## Features
* Convenient syntax: `fd PATTERN` instead of `find -iname '*PATTERN*'`.
* Colorized terminal output (similar to *ls*).
* It's *fast* (see [benchmarks](#benchmark) below).
* Smart case: the search is case-insensitive by default. It switches to
  case-sensitive if the pattern contains an uppercase
  character[\*](http://vimdoc.sourceforge.net/htmldoc/options.html#'smartcase').
* Ignores hidden directories and files, by default.
* Ignores patterns from your `.gitignore`, by default.
* Regular expressions.
* Unicode-awareness.
* The command name is *50%* shorter[\*](https://github.com/ggreer/the_silver_searcher) than
  `find` :-).
* Parallel command execution with a syntax similar to GNU Parallel.

## Demo

![Demo](http://i.imgur.com/kTMFSVU.gif)

## Benchmark
Let's search my home folder for files that end in `[0-9].jpg`. It contains ~150.000
subdirectories and about a million files. For averaging and statistical analysis, I'm using
[bench](https://github.com/Gabriel439/bench). All benchmarks are performed for a "warm
cache". Results for a cold cache are similar.

Let's start with `find`:
```
find ~ -iregex '.*[0-9]\.jpg$'

time                 6.265 s    (6.127 s .. NaN s)
                     1.000 R²   (1.000 R² .. 1.000 R²)
mean                 6.162 s    (6.140 s .. 6.181 s)
std dev              31.73 ms   (0.0 s .. 33.48 ms)
```

`find` is much faster if it does not need to perform a regular-expression search:
```
find ~ -iname '*[0-9].jpg'

time                 2.866 s    (2.754 s .. 2.964 s)
                     1.000 R²   (0.999 R² .. 1.000 R²)
mean                 2.860 s    (2.834 s .. 2.875 s)
std dev              23.11 ms   (0.0 s .. 25.09 ms)
```

Now let's try the same for `fd`. Note that `fd` *always* performs a regular expression
search. The options `--hidden` and `--no-ignore` are needed for a fair comparison,
otherwise `fd` does not have to traverse hidden folders and ignored paths (see below):
```
fd --hidden --no-ignore '.*[0-9]\.jpg$' ~

time                 892.6 ms   (839.0 ms .. 915.4 ms)
                     0.999 R²   (0.997 R² .. 1.000 R²)
mean                 871.2 ms   (857.9 ms .. 881.3 ms)
std dev              15.50 ms   (0.0 s .. 17.49 ms)
```
For this particular example, `fd` is approximately seven times faster than `find -iregex`
and about three times faster than `find -iname`. By the way, both tools found the exact
same 14030 files :smile:.

Finally, let's run `fd` without `--hidden` and `--no-ignore` (this can lead to different
search results, of course):
```
fd '[0-9]\.jpg$' ~

time                 159.5 ms   (155.8 ms .. 165.3 ms)
                     0.999 R²   (0.996 R² .. 1.000 R²)
mean                 158.7 ms   (156.5 ms .. 161.6 ms)
std dev              3.263 ms   (2.401 ms .. 4.298 ms)
```

**Note**: This is *one particular* benchmark on *one particular* machine. While I have
performed quite a lot of different tests (and found consistent results), things might
be different for you! I encourage everyone to try it out on their own.

Concerning *fd*'s speed, the main credit goes to the `regex` and `ignore` crates that are also used
in [ripgrep](https://github.com/BurntSushi/ripgrep) (check it out!).

## Colorized output
`fd` can colorize files by extension, just like `ls`. In order for this to work, the environment
variable [`LS_COLORS`](https://linux.die.net/man/5/dir_colors) has to be set. Typically, the value
of this variable is set by the `dircolors` command which provides a convenient configuration format
to define colors for different file formats.
On most distributions, `LS_COLORS` should be set already. If you are looking for alternative, more
complete (and more colorful) variants, see
[here](https://github.com/seebi/dircolors-solarized) or
[here](https://github.com/trapd00r/LS_COLORS).

## Parallel Command Execution
If the `--exec` flag is specified alongside a command template, a job pool will be created for
generating and executing commands in parallel with each discovered path as the inputs. The syntax
for generating commands is similar to that of GNU Parallel:

- **{}**: A placeholder token that will be replaced with the discovered path.
- **{.}**: Removes the extension from the path.
- **{/}**: Uses the basename of the discovered path.
- **{//}**: Uses the parent of the discovered path.
- **{/.}**: Uses the basename, with the extension removed.

```sh
# Demonstration of parallel job execution
fd -e flac --exec 'sleep 1; echo $\{SHELL}: {}'

# This also works, because `SHELL` is not a valid token
fd -e flac --exec 'sleep 1; echo ${SHELL}: {}'

# The token is optional -- it gets added at the end by default.
fd -e flac --exec 'echo'

# Real world example of converting flac files into opus files.
fd -e flac --type f --exec 'ffmpeg -i "{}" -c:a libopus "{.}.opus"'
```

## Install
With Rust's package manager [cargo](https://github.com/rust-lang/cargo), you can install *fd* via:
```
cargo install fd-find
```
Note that rust version *1.16.0* or later is required.
The release page of this repository also includes precompiled binaries for Linux.

On **macOS**, you can use [Homebrew](http://braumeister.org/formula/fd):
```
brew install fd
```

On **Arch Linux**, you can install the AUR package [fd-rs](https://aur.archlinux.org/packages/fd-rs/) via yaourt, or manually:
```
git clone https://aur.archlinux.org/fd-rs.git
cd fd-rs
makepkg -si
```

On **NixOS**, or any Linux distro you can use [Nix](https://nixos.org/nix/):
```
nix-env -i fd
```

On **Windows**, you can download the pre-built binaries from the [Release page](https://github.com/sharkdp/fd/releases).

## Development
```bash
git clone https://github.com/sharkdp/fd

# Build
cd fd
cargo build

# Run unit tests and integration tests
cargo test

# Install
cargo install
```

## Command-line options
```
USAGE:
    fd [FLAGS/OPTIONS] [<pattern>] [<path>]

FLAGS:
    -H, --hidden            Search hidden files and directories
    -I, --no-ignore         Do not respect .(git)ignore files
    -s, --case-sensitive    Case-sensitive search (default: smart case)
    -a, --absolute-path     Show absolute instead of relative paths
    -L, --follow            Follow symbolic links
    -p, --full-path         Search full path (default: file-/dirname only)
    -0, --print0            Separate results by the null character
    -h, --help              Prints help information
    -V, --version           Prints version information

OPTIONS:
    -d, --max-depth <depth>    Set maximum search depth (default: none)
    -t, --type <filetype>      Filter by type: f(ile), d(irectory), (sym)l(ink)
    -e, --extension <ext>      Filter by file extension
    -c, --color <when>         When to use color in the output:
                               never, auto, always (default: auto)
    -j, --threads <num>        Set number of threads to use for searching:
                               (default: number of available CPU cores)

ARGS:
    <pattern>    the search pattern, a regular expression (optional)
    <path>       the root directory for the filesystem search (optional)
```

## Tutorial

First, to see all command line options, you can get `fd`'s help text by running:
```
fd --help
```

For the sake of this tutorial, let's assume we have a directory with the following file structure:
```
fd_examples
├── .gitignore
├── desub_dir
│   └── old_test.txt
├── not_file
├── sub_dir
│   ├── .here_be_tests
│   ├── more_dir
│   │   ├── .not_here
│   │   ├── even_further_down
│   │   │   ├── not_me.sh
│   │   │   ├── test_seven
│   │   │   └── testing_eight
│   │   ├── not_file -> /Users/fd_user/Desktop/fd_examples/not_file
│   │   └── test_file_six
│   ├── new_test.txt
│   ├── test_file_five
│   ├── test_file_four
│   └── test_file_three
├── test_file_one
├── test_file_two
├── test_one
└── this_is_a_test
```

If `fd` is called with a single argument (the search pattern), it will perform a recursive search
through the current directory. To search for all files that include the string "test", we can
simply run:
```
> fd test
sub_dir/more_dir/even_further_down/test_seven
sub_dir/more_dir/even_further_down/testing_eight
sub_dir/more_dir/test_file_six
sub_dir/test_file_five
sub_dir/test_file_three
sub_dir/test_four
test_file_one
test_file_two
test_one
this_is_a_test
```

The search pattern is treated as a regular expression. To show only entries that start with "test",
we can call:
```
> fd '^test'
sub_dir/more_dir/even_further_down/test_seven
sub_dir/more_dir/even_further_down/testing_eight
sub_dir/more_dir/test_file_six
sub_dir/test_file_five
sub_dir/test_file_three
sub_dir/test_four
test_file_one
test_file_two
test_one
```

Note that `fd` does not show hidden files (`.here_be_tests`) by default. To change this, we can use
the `-H` (or `--hidden`) option:
```
> fd -H test
sub_dir/.here_be_tests
sub_dir/more_dir/even_further_down/test_seven
sub_dir/more_dir/even_further_down/testing_eight
sub_dir/more_dir/test_file_six
sub_dir/test_file_five
sub_dir/test_file_four
sub_dir/test_file_three
test_file_one
test_file_two
test_one
this_is_a_test
```

If we are interested in showing the results from a particular directory, we can specify the root of
the search as a second argument:
```
> fd test sub_dir
sub_dir/more_dir/even_further_down/test_seven
sub_dir/more_dir/even_further_down/testing_eight
sub_dir/more_dir/test_file_six
sub_dir/test_file_five
sub_dir/test_file_three
sub_dir/test_four
```

If we don't give *any* arguments to `fd`, it simply shows all entries in the current directory,
recursively (like `ls -R`):
```
> fd
not_file
sub_dir
sub_dir/more_dir
sub_dir/more_dir/even_further_down
sub_dir/more_dir/even_further_down/test_seven
sub_dir/more_dir/even_further_down/testing_eight
sub_dir/more_dir/not_file
sub_dir/more_dir/test_file_six
sub_dir/test_file_five
sub_dir/test_file_three
sub_dir/test_four
test_file_one
test_file_two
test_one
this_is_a_test
```

If we work in a directory that is a Git repository (or includes several Git repositories), `fd`
does not search folders (and does not show files) that match the `.gitignore` pattern. For example,
imagine we had a `.gitignore` file with the following content:
```
*.sh
```
In this case, `fd` would not show any files that end in `.sh`. To disable this behavior, we can
use the `-I` (or `--ignore`) option:
```
> fd -I me
sub_dir/more_dir/even_further_down/not_me.sh
```

To really search *all* files and directories, we can combine the hidden and ignore features to show
everything (`-HI`):
```
fd -HI 'not|here'
not_file
sub_dir/.here_be_tests
sub_dir/more_dir/.not_here
sub_dir/more_dir/even_further_down/not_me.sh
sub_dir/more_dir/not_file
```

Searching for a file extension is easy too, using the `-e` (or `--extension`) switch for file
extensions:
```
> fd -e sh
sub_dir/more_dir/even_further_down/not_me.sh
```

Next, we can even use a pattern in combination with `-e` to search for a regex pattern over the
files that end in the specified extension.
```
> fd -e txt test
fd_examples/desub_dir/old_test.txt
fd_examples/sub_dir/new_test.txt
```

If we want to run a command for each of the search results, we can use the `-0` option to pipe
the output to `xargs`:
```
> fd -0 'test' | xargs -0 wc -l
```