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 package from the official repos:
```
pacman -S fd-rs
```

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)
    -i, --ignore-case       Case-insensitive 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 colors: never, *auto*, always
    -j, --threads <num>        Set number of threads to use for searching & executing
    -x, --exec <cmd>           Execute the given command for each search result

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

## Tutorial

First, to get an overview of all available command line options, you can either run
`fd -h` for a concise help message (see above) or `fd --help` for a more detailed
version.

### Simple search

*fd* is designed to find entries in your filesystem. The most basic search you can perform is to
run *fd* with a single argument: the search pattern. For example, assume that you want to find an
old script of yours (the name included `netflix`):
``` bash
> fd netfl
Software/python/imdb-ratings/netflix-details.py
```
If called with just a single argument like this, *fd* searches the current directory recursively
for any entries that *contain* the pattern `netfl`.

### Regular expression search

The search pattern is treated as a regular expression. Here, we search for entries that start
with `x` and end with `rc`:
``` bash
> cd /etc
> fd '^x.*rc$'
X11/xinit/xinitrc
X11/xinit/xserverrc
```

### Specifying the root directory

If we want so search a specific directory, it can be given as a second argument to *fd*:
``` bash
> fd passwd /etc
/etc/default/passwd
/etc/pam.d/passwd
/etc/passwd
```

### Running *fd* without any arguments

*fd* can be called with no arguments. This is very useful to get a quick overview of all entries
in the current directory, recursively (similar to `ls -R`):
``` bash
> cd fd/tests
> fd
testenv
testenv/mod.rs
tests.rs
```

### Searching for a particular file extension

Often, we are interested in all files of a particular type. This can be done with the `-e` (or
`--extension`) option. Here, we search for all Markdown files in the fd repository:
``` bash
> cd fd
> fd -e md
CONTRIBUTING.md
README.md
```

The `-e` option can be used in combination with a search pattern:
``` bash
> fd -e rs mod
src/fshelper/mod.rs
src/lscolors/mod.rs
tests/testenv/mod.rs
```

### Hidden and ignored files
By default, *fd* does not search hidden directories and does not show hidden files in the
search results. To disable this behavior, we can use the `-H` (or `--hidden`) option:
``` bash
> fd pre-commit
> fd -H pre-commit
.git/hooks/pre-commit.sample
```

If we work in a directory that is a Git repository (or includes Git repositories), *fd* does not
search folders (and does not show files) that match one of the `.gitignore` patterns. To disable
this behavior, we can use the `-I` (or `--ignore`) option:
``` bash
> fd num_cpu
> fd -I num_cpu
target/debug/deps/libnum_cpus-f5ce7ef99006aa05.rlib
```

To really search *all* files and directories, simply combine the hidden and ignore features to show
everything (`-HI`).

### Using fd with `xargs` or `parallel`

If we want to run a command on all search results, we can pipe the output to `xargs`:
``` bash
> fd -0 -e rs | xargs -0 wc -l
```
Here, the `-0` option tells *fd* to separate search results by the NULL character (instead of     .
newlines) In the same way, the `-0` option of `xargs` tells it to read the input in this way      .