Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser 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, and ot ...

and

Unix-like A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-li ...

operating systems, iconv (an abbreviation of

internationalization In economics, internationalization or internationalisation is the process of increasing involvement of enterprises in international markets, although there is no agreed definition of internationalization. Internationalization is a crucial strateg ...

conversion) is a command-line

program Program, programme, programmer, or programming may refer to: Business and management * Program management, the process of managing several related projects * Time management * Program, a part of planning Arts and entertainment Audio * Progra ...

and a standardized

application programming interface An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how t ...

(API) used to convert between different

character encoding Character encoding is the process of assigning numbers to Graphics, graphical character (computing), characters, especially the written characters of Language, human language, allowing them to be Data storage, stored, Data communication, transmi ...

s. "It can convert from any of these encodings to any other, through Unicode conversion."

History

Initially appearing on the

HP-UX HP-UX (from "Hewlett Packard Unix") is Hewlett Packard Enterprise's proprietary implementation of the Unix operating system, based on Unix System V (initially System III) and first released in 1984. Current versions support HPE Integrity Ser ...

operating system,iconv() as well as the utility was standardized within

XPG4 X/Open group (also known as the Open Group for Unix Systems and incorporated in 1987 as X/Open Company, Ltd.) was a consortium founded by several European UNIX systems manufacturers in 1984 to identify and promote open standards in the field of in ...

and is part of the Single UNIX Specification (SUS).

Implementations

Most

Linux distribution A Linux distribution (often abbreviated as distro) is an operating system made from a software collection that includes the Linux kernel and, often, a package management system. Linux users usually obtain their operating system by downloading one ...

s provide an implementation, either from the

GNU GNU () is an extensive collection of free software (383 packages as of January 2022), which can be used as an operating system or can be used in parts with other operating systems. The use of the completed GNU tools led to the family of operat ...

Standard C Library (included since version 2.1, February 1999), or the more traditional GNU libiconv, for systems based on other Standard C Libraries. The iconv function on both is licensed as

LGPL The GNU Lesser General Public License (LGPL) is a free-software license published by the Free Software Foundation (FSF). The license allows developers and companies to use and integrate a software component released under the LGPL into their own ...

, so it is linkable with closed source applications. Unlike the libraries, the iconv utility is licensed under

GPL The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the four freedoms to run, study, share, and modify the software. The license was the first copyleft for general u ...

in both implementations. The GNU libiconv implementation is portable, and can be used on various UNIX-like and non-UNIX systems. Version 0.3 dates from December 1999. The

uconv In computing, uconv is a command-line tool that is bundled with International Components for Unicode that converts text files between different character encodings. It is very similar to the ''iconv'' command that is part of the Single UNIX Specif ...

utility from

International Components for Unicode International Components for Unicode (ICU) is an open-source project of mature C/C++ and Java libraries for Unicode support, software internationalization, and software globalization. ICU is widely portable to many operating systems and environm ...

provides an iconv-compatible command-line syntax for transcoding. Most BSD systems use NetBSD's implementation, first appeared in December 2004.

Support

Currently, over a hundred different character encodings are supported.

Ports

Under

Microsoft Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

, the iconv library and the utility is provided by GNU's libiconv found in

Cygwin Cygwin ( ) is a POSIX-compatible programming and runtime environment that runs natively on Microsoft Windows. Under Cygwin, source code designed for Unix-like operating systems may be compiled with minimal modification and executed. The Cygwin in ...

and

GnuWin32 The G''nu''W''in''32 project provides native ports in the form of executable computer programs, patches, and source code for various GNU and open source tools and software, much of it modified to run on the 32-bit Windows platform. The ports inc ...

environments; there is also a "purely Win32" implementation called "win-iconv" that uses Windows' built-in routines for conversion. The iconv function is also available for many programming languages. The command has also been ported to the

IBM i IBM i (the ''i'' standing for ''integrated'') is an operating system developed by IBM for IBM Power Systems. It was originally released in 1988 as OS/400, as the sole operating system of the IBM AS/400 line of systems. It was renamed to i5/OS in ...

operating system.

Usage

stdin 

In computer programming, standard streams are interconnected input and output communication channels between a computer program and its environment when it begins execution. The three input/output (I/O) connections are called standard input (stdin ...

can be converted from

ISO-8859-1 ISO/IEC 8859-1:1998, ''Information technology — 8-bit single-byte coded graphic character sets — Part 1: Latin alphabet No. 1'', is part of the ISO/IEC 8859 series of ASCII-based standard character encodings, first edition published in 1 ...

to current locale and output to

stdout 

In computer programming, standard streams are interconnected input and output communication channels between a computer program and its environment when it begins execution. The three input/output (I/O) connections are called standard input (stdin ...

using: iconv -f iso-8859-1 An input file infile can be converted from ISO-8859-1 to UTF-8 and output to output file outfile using: iconv -f iso-8859-1 -t utf-8 -o

References

External links

iconv() OpenGroup Standards page

GNU libiconv

win_iconv
HP software Unix text processing utilities Unix SUS2008 utilities IBM i Qshell commands C POSIX library {{Unix-stub