# dupl [](https://travis-ci.org/mibk/dupl)
**dupl** is a tool written in Go for finding code clones. So far it can find clones only
in the Go source files. The method uses suffix tree for serialized ASTs. It ignores values
of AST nodes. It just operates with their types (e.g. `if a == 13 {}` and `if x == 100 {}` are
considered the same provided it exceeds the minimal token sequence size).
Due to the used method dupl can report so called "false positives" on the output. These are
the ones we do not consider clones (whether they are too small, or the values of the matched
tokens are completely different).
## Installation
```bash
go get -u github.com/golangci/dupl
```
## Usage
```
Usage of dupl:
dupl [flags] [paths]
Paths:
If the given path is a file, dupl will use it regardless of
the file extension. If it is a directory it will recursively
search for *.go files in that directory.
If no path is given dupl will recursively search for *.go
files in the current directory.
Flags:
-files
read file names from stdin one at each line
-html
output the results as HTML, including duplicate code fragments
-plumbing
plumbing (easy-to-parse) output for consumption by scripts or tools
-t, -threshold size
minimum token sequence size as a clone (default 15)
-vendor
check files in vendor directory
-v, -verbose
explain what is being done
Examples:
dupl -t 100
Search clones in the current directory of size at least
100 tokens.
dupl $(find app/ -name '*_test.go')
Search for clones in tests in the app directory.
find app/ -name '*_test.go' |dupl -files
The same as above.
```
## Example
The reduced output of this command with the following parameters for the [Docker](https://www.docker.com) source code
looks like [this](http://htmlpreview.github.io/?https://github.com/golangci/dupl/blob/master/_output_example/docker.html).
```bash
$ dupl -t 200 -html >docker.html
```