# Standard Input

The **stdin** plugin allows to retrieve valid JSON text messages over the standard input interface (stdin). In order to use it, specify the plugin name as the input, e.g:

```bash
$ fluent-bit -i stdin -o stdout
```

As input data the *stdin* plugin recognize the following JSON data formats:

```bash
1. { map => val, map => val, map => val }
2. [ time, { map => val, map => val, map => val } ]
```

A better example to demonstrate how it works will be through a *Bash* script that generates messages and writes them to [Fluent Bit](http://fluentbit.io). Write the following content in a file named *test.sh*:

```bash
#!/bin/sh

while :; do
  echo -n "{\"key\": \"some value\"}"
  sleep 1
done
```

Give the script execution permission:

```bash
$ chmod 755 test.sh
```

Now lets start the script and [Fluent Bit](http://fluentbit.io) in the following way:

```bash
$ ./test.sh | fluent-bit -i stdin -o stdout
Fluent Bit v1.x.x
* Copyright (C) 2019-2020 The Fluent Bit Authors
* Copyright (C) 2015-2018 Treasure Data
* Fluent Bit is a CNCF sub-project under the umbrella of Fluentd
* https://fluentbit.io

[2016/10/07 21:44:46] [ info] [engine] started
[0] stdin.0: [1475898286, {"key"=>"some value"}]
[1] stdin.0: [1475898287, {"key"=>"some value"}]
[2] stdin.0: [1475898288, {"key"=>"some value"}]
[3] stdin.0: [1475898289, {"key"=>"some value"}]
[4] stdin.0: [1475898290, {"key"=>"some value"}]
```