Search results
Results from the WOW.Com Content Network
In the C and C++ programming languages, unistd.h is the name of the header file that provides access to the POSIX operating system API. [1] It is defined by the POSIX.1 standard, the base of the Single Unix Specification , and should therefore be available in any POSIX-compliant operating system and compiler .
Another solution is to use an include guard in each header file. [4] The C standard library is declared as a collection of header files. The C++ standard library is similar, but the declarations may be provided by the compiler without reading an actual file. C standard header files are named with a .h file name extension, as in #include <stdio ...
[5] [6] [7] An X-Macro is a header file. Commonly, these use the extension .def instead of the traditional .h. This file contains a list of similar macro calls, which can be referred to as "component macros." The include file is then referenced repeatedly. Many compilers define additional, non-standard macros.
The C preprocessor processes inclusion directives like #include "foo.h" to include "foo.h" and transcludes the code of that file into a copy of the main file often called the translation unit. However, if an #include directive for a given file appears multiple times during compilation, the code will effectively be duplicated in that file.
direct.h is a C/C++ header file provided by Microsoft Windows, which contains functions for manipulating file system directories. Some POSIX functions that do similar things are in unistd.h . Member functions
The C POSIX library is a specification of a C standard library for POSIX systems. It was developed at the same time as the ANSI C standard. Some effort was made to make POSIX compatible with standard C; POSIX includes additional functions to those introduced in standard C.
The C standard library, sometimes referred to as libc, [1] is the standard library for the C programming language, as specified in the ISO C standard. [2] Starting from the original ANSI C standard, it was developed at the same time as the C POSIX library, which is a superset of it. [3]
This suggests that unistd.h is part of the C or C++ language standards when actually it's part of the POSIX standards. To fix this, I would turn it around: > On POSIX operating systems, unistd.h is the name of the header file that provides system API declarations to programs written in the C or C++ programming languages.