# ICONV_OPEN

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
ERRORS
CONFORMING TO
SEE ALSO

## NAME

iconv_open − allocate descriptor for character set conversion

## SYNOPSIS

#include <iconv.h>

iconv_t iconv_open (const char* tocode, const char* fromcode);

## DESCRIPTION

The iconv_open function allocates a conversion descriptor suitable for converting byte sequences from character encoding fromcode to character encoding tocode.

The values permitted for fromcode and tocode and the supported combinations are system dependent. For the libiconv library, the following encodings are supported, in all combinations.
European languages

ASCII, ISO−8859−{1,2,3,4,5,7,9,10,13,14,15,16}, KOI8−R, KOI8−U, KOI8−RU, CP{1250,1251,1252,1253,1254,1257}, CP{850,866,1131}, Mac{Roman,CentralEurope,Iceland,Croatian,Romania}, Mac{Cyrillic,Ukraine,Greek,Turkish}, Macintosh

Semitic languages

ISO−8859−{6,8}, CP{1255,1256}, CP862, Mac{Hebrew,Arabic}

Japanese

EUC−JP, SHIFT_JIS, CP932, ISO−2022−JP, ISO−2022−JP−2, ISO−2022−JP−1, ISO-2022−JP−MS

Chinese

EUC−CN, HZ, GBK, CP936, GB18030, GB18030:2022, EUC−TW, BIG5, CP950, BIG5−HKSCS, BIG5−HKSCS:2004, BIG5−HKSCS:2001, BIG5−HKSCS:1999, ISO−2022−CN, ISO−2022−CN−EXT

| Korean |  | EUC−KR, CP949, ISO−2022−KR, JOHAB |

Armenian

ARMSCII−8

Georgian

Georgian−Academy, Georgian−PS

| Tajik |  | KOI8−T |
| Kazakh |  | PT154, RK1048 |
| Thai |  | TIS−620, CP874, MacThai |

Laotian

MuleLao−1, CP1133

Vietnamese

VISCII, TCVN, CP1258

Platform specifics

HP−ROMAN8, NEXTSTEP

Full Unicode

UTF−8
UCS−2, UCS−2BE, UCS−2LE
UCS−4, UCS−4BE, UCS−4LE
UTF−16, UTF−16BE, UTF−16LE
UTF−32, UTF−32BE, UTF−32LE
UTF−7
C99, JAVA

Full Unicode, in terms of uint16_t or uint32_t

(with machine dependent endianness and alignment)
UCS−2−INTERNAL, UCS−4−INTERNAL

Locale dependent, in terms of char or wchar_t

(with machine dependent endianness and alignment, and with semantics depending on the OS and the current LC_CTYPE locale facet)
char, wchar_t

When configured with the option −−enable−extra−encodings, it also provides support for a few extra encodings:
European languages

CP{437,737,775,852,853,855,857,858,860,861,863,865,869,1125}

Semitic languages

CP864

Japanese

EUC−JISX0213, Shift_JISX0213, ISO−2022−JP−3

Chinese

BIG5−2003 (experimental)

Turkmen

TDS565

Platform specifics

ATARIST, RISCOS−LATIN1

EBCDIC compatible (not ASCII compatible, very rarely used)

European languages:
IBM-{037,273,277,278,280,282,284,285,297,423,500,870,871,875,880},
IBM-{905,924,1025,1026,1047,1112,1122,1123,1140,1141,1142,1143},
IBM-{1144,1145,1146,1147,1148,1149,1153,1154,1155,1156,1157,1158},
IBM-{1165,1166,4971}
Semitic languages:
IBM-{424,425,12712,16804}
Persian:
IBM-1097
Thai:
IBM-{838,1160}
Laotian:
IBM-1132
Vietnamese:
IBM-{1130,1164}
Indic languages:
IBM-1137

The empty encoding name "" is equivalent to "char": it denotes the locale dependent character encoding.

When the string "//TRANSLIT" is appended to tocode, transliteration is activated. This means that when a character cannot be represented in the target character set, it can be approximated through one or several characters that look similar to the original character.

When the string "//IGNORE" is appended to tocode, invalid multibyte sequences in the input and characters that cannot be represented in the target character set will be silently discarded.

When the string "//NON_IDENTICAL_DISCARD" is appended to tocode, characters that cannot be represented in the target character set will be silently discarded.

The resulting conversion descriptor can be used with iconv any number of times. It remains valid until deallocated using iconv_close.

A conversion descriptor contains a conversion state. After creation using iconv_open, the state is in the initial state. Using iconv modifies the descriptor’s conversion state. (This implies that a conversion descriptor can not be used in multiple threads simultaneously.) To bring the state back to the initial state, use iconv with NULL as inbuf argument.

## RETURN VALUE

The iconv_open function returns a freshly allocated conversion descriptor. In case of error, it sets errno and returns (iconv_t)(−1).

## ERRORS

The following error can occur, among others:

| EINVAL |  | The conversion from fromcode to tocode is not supported by the implementation.

## CONFORMING TO

POSIX:2024

## SEE ALSO

iconv(3) iconvctl(3) iconv_close(3)