iconv_open.3

libiconv是一个很不错的字符集转换库。程序接口也很简单

.\" Copyright (c) Bruno Haible <[e-mail]>
.\"
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.\" modify it under the terms of the GNU General Public License as
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.\" References consulted:
.\"   GNU glibc-2 source code and manual
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.TH ICONV_OPEN 3  "May 26, 2002" "GNU" "Linux Programmer's Manual"
.SH NAME
iconv_open \- allocate descriptor for character set conversion
.SH SYNOPSIS
.nf
.B #include <iconv.h>
.sp
.BI "iconv_t iconv_open (const char* " tocode ", const char* " fromcode );
.fi
.SH DESCRIPTION
The \fBiconv_open\fP function allocates a conversion descriptor suitable
for converting byte sequences from character encoding \fIfromcode\fP to
character encoding \fItocode\fP.
.PP
The values permitted for \fIfromcode\fP and \fItocode\fP and the supported
combinations are system dependent. For the libiconv library, the following
encodings are supported, in all combinations.
.TP
European languages
.nf
.fi
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},
Mac{Roman,CentralEurope,Iceland,Croatian,Romania},
Mac{Cyrillic,Ukraine,Greek,Turkish},
Macintosh
.TP
Semitic languages
.nf
.fi
ISO-8859-{6,8}, CP{1255,1256}, CP862, Mac{Hebrew,Arabic}
.TP
Japanese
.nf
.fi
EUC-JP, SHIFT_JIS, CP932, ISO-2022-JP, ISO-2022-JP-2, ISO-2022-JP-1
.TP
Chinese
.nf
.fi
EUC-CN, HZ, GBK, GB18030, EUC-TW, BIG5, CP950, BIG5-HKSCS,
ISO-2022-CN, ISO-2022-CN-EXT
.TP
Korean
.nf
.fi
EUC-KR, CP949, ISO-2022-KR, JOHAB
.TP
Armenian
.nf
.fi
ARMSCII-8
.TP
Georgian
.nf
.fi
Georgian-Academy, Georgian-PS
.TP
Tajik
.nf
.fi
KOI8-T
.TP
Thai
.nf
.fi
TIS-620, CP874, MacThai
.TP
Laotian
.nf
.fi
MuleLao-1, CP1133
.TP
Vietnamese
.nf
.fi
VISCII, TCVN, CP1258
.TP
Platform specifics
.nf
.fi
HP-ROMAN8, NEXTSTEP
.TP
Full Unicode
.nf
.fi
UTF-8
.nf
.fi
UCS-2, UCS-2BE, UCS-2LE
.nf
.fi
UCS-4, UCS-4BE, UCS-4LE
.nf
.fi
UTF-16, UTF-16BE, UTF-16LE
.nf
.fi
UTF-32, UTF-32BE, UTF-32LE
.nf
.fi
UTF-7
.nf
.fi
C99, JAVA
.TP
Full Unicode, in terms of \fBuint16_t\fP or \fBuint32_t\fP
(with machine dependent endianness and alignment)
.nf
.fi
UCS-2-INTERNAL, UCS-4-INTERNAL
.TP
Locale dependent, in terms of \fBchar\fP or \fBwchar_t\fP
(with machine dependent endianness and alignment, and with semantics
depending on the OS and the current LC_CTYPE locale facet)
.nf
.fi
char, wchar_t
.PP
When configured with the option \fB\-\-enable-extra-encodings\fP, it also
provides support for a few extra encodings:
.TP
European languages
.nf
CP{437,737,775,852,853,855,857,858,860,861,863,865,869,1125}
.fi
.TP
Semitic languages
.nf
.fi
CP864
.TP
Japanese
.nf
.fi
EUC-JISX0213, Shift_JISX0213, ISO-2022-JP-3
.TP
Turkmen
.nf
.fi
TDS565
.TP
Platform specifics
.nf
.fi
RISCOS-LATIN1
.PP
The empty encoding name "" is equivalent to "char": it denotes the
locale dependent character encoding.
.PP
When the string "//TRANSLIT" is appended to \fItocode\fP, 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
similarly looking characters.
.PP
When the string "//IGNORE" is appended to \fItocode\fP, characters that
cannot be represented in the target character set will be silently discarded.
.PP
The resulting conversion descriptor can be used with \fBiconv\fP any number
of times. It remains valid until deallocated using \fBiconv_close\fP.
.PP
A conversion descriptor contains a conversion state. After creation using
\fBiconv_open\fP, the state is in the initial state. Using \fBiconv\fP
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 \fBiconv\fP with NULL as \fIinbuf\fP
argument.
.SH "RETURN VALUE"
The \fBiconv_open\fP function returns a freshly allocated conversion
descriptor. In case of error, it sets \fBerrno\fP and returns (iconv_t)(-1).
.SH ERRORS
The following error can occur, among others:
.TP
.B EINVAL
The conversion from \fIfromcode\fP to \fItocode\fP is not supported by the
implementation.
.SH "CONFORMING TO"
UNIX98
.SH "SEE ALSO"
.BR iconv "(3), " iconv_close (3)