ICONV_OPEN(3)

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)