conio.h is a C header file used mostly by

MS-DOS MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few op ...

compilers to provide console

input/output In computing, input/output (I/O, i/o, or informally io or IO) is the communication between an information processing system, such as a computer, and the outside world, such as another computer system, peripherals, or a human operator. Inputs a ...

. It is not part of the

C standard library The C standard library, sometimes referred to as libc, is the standard library for the C (programming language), C programming language, as specified in the ISO C standard.International Organization for Standardization, ISO/International Electrote ...

ISO C ANSI C, ISO C, and Standard C are successive standards for the C programming language published by the American National Standards Institute (ANSI) and ISO/IEC JTC 1/SC 22/WG 14 of the International Organization for Standardization (ISO) and th ...

, nor is it defined by

POSIX The Portable Operating System Interface (POSIX; ) is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines application programming interfaces (APIs), along with comm ...

. This header declares several useful library functions for performing "istream input and output" from a program. Most C compilers that target

DOS DOS (, ) is a family of disk-based operating systems for IBM PC compatible computers. The DOS family primarily consists of IBM PC DOS and a rebranded version, Microsoft's MS-DOS, both of which were introduced in 1981. Later compatible syste ...

, Windows 3.x,

Phar Lap Phar Lap (4 October 1926 – 5 April 1932) was a New Zealand-born champion Australian Thoroughbred horse racing, racehorse. Achieving great success during his distinguished career, his initial underdog status gave people hope during the ear ...

, DOSX,

OS/2 OS/2 is a Proprietary software, proprietary computer operating system for x86 and PowerPC based personal computers. It was created and initially developed jointly by IBM and Microsoft, under the leadership of IBM software designer Ed Iacobucci, ...

, or

Win32 The Windows API, informally WinAPI, is the foundational application programming interface (API) that allows a computer program to access the features of the Microsoft Windows operating system in which the program is running. Programs can acces ...

have this header and supply the associated library functions in the default C library. Most C compilers that target

UNIX Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...

and

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

do not have this header and do not supply the library functions. Some embedded systems or

cc65 cc65 is a cross development package for 6502 and 65C02 targets, including a macro assembler, a C cross compiler, linker, librarian and several other tools. Overview cc65 is based on a native C compiler that was originally adapted for the A ...

use a conio-compatible library. The library functions declared by vary somewhat from compiler to compiler. As originally implemented in

Lattice C The Lattice C Compiler was released in June 1982 by Lifeboat Associates and was the first C compiler for the IBM Personal Computer. The compiler sold for $500 and would run on PC DOS or MS-DOS (which at the time were the same product with differ ...

, the various functions mapped directly to few of the first

INT 21H The DOS API is an API which originated with 86-DOS and is used in MS-DOS/ PC DOS and other DOS-compatible operating systems. Most calls to the DOS API are invoked using software interrupt 21h ( INT 21h). By calling INT 21h with a subfuncti ...

functions. The library supplied with

Borland Borland Software Corporation was a computing technology company founded in 1983 by Niels Jensen, Ole Henriksen, Mogens Glad, and Philippe Kahn. Its main business was developing and selling software development and software deployment products. B ...

Turbo C Turbo C is a discontinued integrated development environment (IDE) and compiler for the C programming language from Borland. First introduced in 1987, it was noted for its integrated development environment, small size, fast compile speed, com ...

did not use the DOS API but instead accessed video RAM directly for output and used

BIOS interrupt call BIOS implementations provide interrupts that can be invoked by operating systems and application programs to use the facilities of the firmware on IBM PC compatible computers. Traditionally, BIOS calls are mainly used by DOS programs and some ot ...

s. This library also has additional functions inspired from the successful

Turbo Pascal Turbo Pascal is a software development system that includes a compiler and an integrated development environment (IDE) for the programming language Pascal (programming language), Pascal running on the operating systems CP/M, CP/M-86, and MS-DOS. ...

one. Compilers that target non-DOS operating systems, such as

or OS/2, provide similar solutions; the unix-related

curses A curse (also called an imprecation, malediction, execration, malison, anathema, or commination) is any expressed wish that some form of adversity or misfortune will befall or attach to one or more persons, a place, or an object. In particular ...

library is very common here. Another example is SyncTERM's ciolib. The version of done by DJ Delorie for the GO32 extender is particularly extensive.

Functions

References

{{reflist

External links

Microsoft's documentation

- explanation and suggestions for non-standard console IO
Borland-style CONIO implementation for MinGW/Dev-C++

C (programming language) headers Conio Text mode Text user interface Text user interface libraries