gmime-iconv: GMime 3.0 Reference Manual

gmime-iconv

gmime-iconv — Low-level routines for converting text from one charset to another

Functions

iconv_t	g_mime_iconv_open ()
#define	g_mime_iconv()
int	g_mime_iconv_close ()

Description

These functions are wrappers around the system iconv(3) routines. The purpose of this wrapper is to use the appropriate system charset alias for the MIME charset names given as arguments.

Functions

g_mime_iconv_open ()

iconv_t
g_mime_iconv_open (const char *to,
                   const char *from);

Allocates a coversion descriptor suitable for converting byte sequences from charset from to charset to . The resulting descriptor can be used with iconv() (or the g_mime_iconv() wrapper) any number of times until closed using g_mime_iconv_close().

See the manual page for iconv_open(3) for further details.

[skip]

Parameters

to	charset to convert to
from	charset to convert from

Returns

a new conversion descriptor for use with g_mime_iconv() on success or (iconv_t) -1 on fail as well as setting an appropriate errno value.

g_mime_iconv()

#define             g_mime_iconv(cd,inbuf,inleft,outbuf,outleft)

The argument cd must be a conversion descriptor created using the function g_mime_iconv_open.

The main case is when inbuf is not NULL and *inbuf is not NULL. In this case, the g_mime_iconv function converts the multibyte sequence starting at *inbuf to a multibyte sequence starting at *outbuf. At most *inleft bytes, starting at *inbuf, will be read. At most *outleft bytes, starting at *outbuf, will be written.

The g_mime_iconv function converts one multibyte character at a time, and for each character conversion it increments *inbuf and decrements *inleft by the number of converted input bytes, it increments *outbuf and decrements *outleft by the number of converted output bytes, and it updates the conversion state contained in cd . The conversion can stop for four reasons:

An invalid multibyte sequence is encountered in the input. In this case it sets errno to EILSEQ and returns (size_t)(-1). *inbuf is left pointing to the beginning of the invalid multibyte sequence.
The input byte sequence has been entirely converted, i.e. *inleft has gone down to 0. In this case g_mime_iconv returns the number of non-reversible conversions performed during this call.
An incomplete multibyte sequence is encountered in the input, and the input byte sequence terminates after it. In this case it sets errno to EINVAL and returns (size_t)(-1). *inbuf is left pointing to the beginning of the incomplete multibyte sequence.
The output buffer has no more room for the next converted character. In this case it sets errno to E2BIG and returns (size_t)(-1).

A different case is when inbuf is NULL or *inbuf is NULL, but outbuf is not NULL and *outbuf is not NULL. In this case, the g_mime_iconv function attempts to set cd 's conversion state to the initial state and store a corresponding shift sequence at *outbuf. At most *outleft bytes, starting at *outbuf, will be written. If the output buffer has no more room for this reset sequence, it sets errno to E2BIG and returns (size_t)(-1). Otherwise it increments *outbuf and decrements *outleft by the number of bytes written.

A third case is when inbuf is NULL or *inbuf is NULL, and outbuf is NULL or *outbuf is NULL. In this case, the g_mime_iconv function sets cd 's conversion state to the initial state.

Parameters

cd	iconv_t conversion descriptor
inbuf	input buffer
inleft	number of bytes left in `inbuf`
outbuf	output buffer
outleft	number of bytes left in `outbuf`

Returns

the number of characters converted in a nonreversible way during this call; reversible conversions are not counted. In case of error, it sets errno and returns (size_t)(-1).

g_mime_iconv_close ()

int
g_mime_iconv_close (iconv_t cd);

Closes the iconv descriptor cd .

See the manual page for iconv_close(3) for further details.

[skip]

Parameters

iconv conversion descriptor

Returns

0 on success or -1 on fail as well as setting an appropriate errno value.