# Pipelines

> Source: https://learn-bash.net/pipelines/
> Part of Learn Bash, free to read.

Pipelines, often called pipes, is a way to chain commands and connect output from one command to the input of the next.
A pipeline is represented by the pipe character: `|`. It’s particularly handy when a complex or long input is required for a command.

```bash
command1 | command2
```

By default pipelines redirects only the standard output, if you want to include the standard error you need to use the form `|&` which is a short hand for `2>&1 |`.

### Example:

Imagine you quickly want to know the number of entries in a directory, you can use a pipe to redirect the output of the `ls` command to the `wc` command with option `-l`.

```bash
ls / | wc -l
```

Then you want to see only the first 10 results

```bash
ls / | head
```

*Note: head outputs the first 10 lines by default, use option -n to change this behavior*