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

Unix-like A Unix-like (sometimes referred to as UN*X, *nix 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 Uni ...

operating systems, iconv (an abbreviation of

internationalization 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 strategy not only for ...

conversion) is a command-line program and a standardized

application programming interface An application programming interface (API) is a connection between computers or between computer programs. It is a type of software Interface (computing), interface, offering a service to other pieces of software. A document or standard that des ...

(API) used to convert between different

character encoding Character encoding is the process of assigning numbers to graphical character (computing), characters, especially the written characters of human language, allowing them to be stored, transmitted, and transformed using computers. The numerical v ...

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 a proprietary software, proprietary implementation of the Unix operating system developed by Hewlett Packard Enterprise; current versions support HPE Integrity Servers, based on Intel's Itanium architect ...

operating system,iconv() as well as the utility was standardized within XPG4 and is part of the

Single UNIX Specification The Single UNIX Specification (SUS) is a standard for computer operating systems, compliance with which is required to qualify for using the "UNIX" trademark. The standard specifies programming interfaces for the C language, a command-line shell, ...

(SUS).

Implementations

Most

Linux distribution A Linux distribution, often abbreviated as distro, is an operating system that includes the Linux kernel for its kernel functionality. Although the name does not imply product distribution per se, a distro—if distributed on its own—is oft ...

s provide an implementation, either from the

GNU GNU ( ) is an extensive collection of free software (394 packages ), 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 operating systems popu ...

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 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 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 envir ...

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

musl musl is a C standard library intended for operating systems based on the Linux kernel, released under the MIT License. It was developed by Rich Felker to write a clean, efficient, and standards-conformant libc implementation. Overview musl wa ...

C library implements the iconv function with support for all encodings specified by the

WHATWG The Web Hypertext Application Technology Working Group (WHATWG) is a community of people interested in evolving HTML and related technologies. The WHATWG was founded by individuals from Apple Inc., the Mozilla Foundation and Opera Software, ...

Encoding Standard.

Support

Currently, over a hundred different character encodings are supported in the GNU variant.

Ports

Under

Microsoft Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

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

Cygwin Cygwin ( ) is a free and open-source Unix-like environment and command-line interface (CLI) for Microsoft Windows. The project also provides a software repository containing open-source packages. Cygwin allows source code for Unix-like operati ...

and GnuWin32 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 2 ...

operating system.

Usage

stdin 

In computer programming, standard streams are preconnected 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 computing, 8-bit single-byte coded graphic character (computing), character sets—Part 1: Latin alphabet No. 1'', is part of the ISO/IEC 8859 series of ASCII-based standard character enc ...

to current locale and output to

stdout 

In computer programming, standard streams are preconnected 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 libiconvcode

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