Changing C standards
In this recipe, we will be learning and exploring different C standards, what they are, why they matter, and how they affect our programs. We will also learn how to set the C standard at compile time.
The most commonly used C standards today are C89, C99, and C11 (C89 for 1989, C11 for 2011, and so on). Many compilers still default to using C89 because it's the most compatible, widespread, and complete implementation. However, C99 is a more flexible and modern implementation. Often, under newer versions of Linux, the default is C18, together with some POSIX standards.
We will write two programs and compile them with both C89 and C99, and see their differences.
All you need for this recipe is a Linux computer with GCC installed, preferably via the meta-package or package group described in Chapter 1, Getting the Necessary Tools and Writing our First Linux Programs.
How to do it…
Follow along to explore the differences...