libiconv (1.17)

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iconv_open.3
ICONV_OPEN(3) Linux Programmer's Manual 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 libi‐
conv 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, 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 charac‐
ter 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, 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 deallo‐
cated 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:2001

SEE ALSO
iconv(3) iconvctl(3) iconv_close(3)

GNU January 23, 2022 ICONV_OPEN(3)