## Search for Packages
```bash
$ apt-cache search <pattern>
```

## Build Dependencies
```bash
$ sudo apt-get build-dep <package>
```

## Get Source
```bash
$ apt-get source <package>
```

## Which package provides a file?

The `apt-file` utility is useful. Install it with
```bash
$ apt-get install apt-file
```
and then for example
```bash
$ apt-file search GL/gl.h
```