@node Introduction
@chapter Introduction

@cpindex Hosted environment
@cpindex Unhosted environment
The C programming language does not provide
an built-in functions or constant values.
It only, provides a few basic numerical
data types. In fact, it does not even call
the function @code{main}. All of these
facilities are provided by the C standard
library. A C environment with a C standard
library is called a hosted environment; one
without it is called an unhosted environment.
Almost all software written in C are written
in hosted C. There are practically only two
types of software not written in an unhosted
environment, the C standard library (commonly
called @command{libc}) implementations
themself, and operating system kernels and
programs started before it.

The Stockholm C Standard Library, or simply
@command{slibc}, described in this document,
is an implementaton of a C standard library for
@sc{POSIX} systems. It is aimed at supporting
@sc{C99} and newer dialects of @sc{ISO}@tie{}C,
and no other programming languages. @command{slibc}
is not aimed to replace an existing @command{libc}
implementation or suiting a particular niche.
Rather, @command{slibc} is intended as a learning
experiences for its developer. It does however,
add extensions (features) that are not defined
by the standards it covers or even existing
@command{libc} implementations.

@command{slibc}'s header files document all
features it implements. This manual is intended
as a more extensive documentation. It is written
with the assumption that you are familiar with
the C programming language.