<p>What are some uses of <code>#pragma</code> in C, with examples?</p>

Putting
```
#pragma once
```
at the top of your header file will ensure that it is only included once. Note that
```
#pragma once
```
is not standard C99, but supported by most modern compilers.
An alternative is to use include guards (e.g.
```
#ifndef MY_FILE #define MY_FILE ... #endif /* MY_FILE */
```
)