illumos: manual page: kiconvstr.9f

KICONVSTR(9F) Kernel Functions for Drivers KICONVSTR(9F)

NAME

kiconvstr - string-based code conversion function

SYNOPSIS

#include <sys/types.h>
#include <sys/errno.h>
#include <sys/sunddi.h>

size_t kiconvstr(const char *tocode, const char *fromcode, char *inarray,
size_t *inlen, char *outarray, size_t *outlen, int flag, int *errno);

INTERFACE LEVEL

illumos DDI specific (illumos DDI).

PARAMETERS

The parameters for the kiconvstr function are as follows:

tocode
Points to a target codeset name string. Supported names are
specified at kiconv_open().

fromcode
Points to a source codeset name string. Supported names are
specified at kiconv_open().

inarray
Points to a byte array containing a sequence of character
bytes in fromcode codeset to be converted.

inlen
As an input parameter, the number of bytes to be converted in
inarray. As an output parameter, the number of bytes in
inarray still not converted after the conversion.

outarray
Points to a byte array where converted character bytes in
tocode codeset can be saved.

outlen
As an input parameter, the number of available bytes at
outarray where converted character bytes can be saved. As an
output parameter, the number of bytes still available at
outarray after the conversion.

flag
Indicates possible conversion options constructed by a
bitwise-inclusive-OR of the following values:

KICONV_IGNORE_NULL

Normally, kiconvstr() stops the conversion if it
encounters NULL byte even if the current inlen is
pointing to a value larger than zero.

If this option is set, a NULL byte does not stop the
conversion and the conversion continues until the number
of inarray bytes pointed by inlen are all consumed for
conversion or an error happened.

KICONV_REPLACE_INVALID

Normally, kiconvstr() stops the conversion if it
encounters illegal or incomplete characters with
corresponding errno values.

If this option is set, kiconvstr() does not stop the
conversion and instead treats such characters as non-
identical conversion cases.

errno
Indicates the error when conversion is not completed or
failed. The following are possible values:

EILSEQ
The input conversion was stopped due to an input
byte that does not belong to the input codeset.

E2BIG
The input conversion was stopped due to lack of
space in the output array.

EINVAL
The input conversion was stopped due to an
incomplete character or shift sequence at the
end of the input array.

EBADF
The requested conversion is not supported.

DESCRIPTION

The kiconvstr() function converts the sequence of characters from one
codeset, in the array specified by inarray, into a sequence of
corresponding characters in another codeset, in the array specified by
outarray. The codesets are those specified in fromcode and tocode
parameters. The inarray parameter points to a character byte array to the
first character in the input array and inlen indicates the number of
bytes to the end of the array to be converted. The outarray parameter
points to a character byte array to the first available byte in the
output array and outlen indicates the number of the available bytes to
the end of the array. Unless KICONV_IGNORE_NULL is specified at flag,
kiconvstr() function normally stops when it encounters NULL byte from the
input array regardless of the current inlen value.

If KICONV_REPLACE_INVALID is not specified at flag and if a sequence of
input bytes does not form a valid character in the specified codeset,
conversion stops after the previous successfully converted character. If
KICONV_REPLACE_INVALID is not specified in flag and if the input array
ends with an incomplete character or shift sequence, conversion stops
after the previous successfully converted bytes. If the output array is
not large enough to hold the entire converted input, conversion stops
just prior to the input bytes that would cause the output array to
overflow. The value pointed to by inlen is decremented to reflect the
number of bytes still not converted in the input array. The value pointed
to by outlen is decremented to reflect the number of bytes still
available in the output array.

If kiconvstr() encounters a character in the input array that is legal,
but for which an identical character does not exist in the target
codeset, kiconvstr() performs an implementation-defined conversion (that
is, a non-identical conversion) on this character.

If KICONV_REPLACE_INVALID is specified in flag and if kiconvstr()
encounters illegal or incomplete characters in the input array, instead
of stopping the conversion, kiconvstr() treats such characters as if
they are non-identical characters and does non-identical conversions on
such character bytes.

RETURN VALUES

The kiconvstr() function updates the values pointed to by the inlen and
outlen parameters to reflect the extent of the conversion and returns the
number of non-identical conversions performed. If the entire string in
the input array is converted, the value pointed to by inlen is 0. If the
input conversion is stopped due to any conditions mentioned above, the
value pointed to by inlen is non-zero and errno is set to indicate the
condition. If an error occurs, kiconvstr() returns (size_t)-1 and sets
errno to indicate the error.

CONTEXT

kiconvstr() can be called from user or interrupt context.

EXAMPLES

Example 1: Performing a Code Conversion

The following example converts a NULL-terminated ISO8859-2 pathname
string to a UTF-8 string and treats illegal and incomplete characters as
non-identical conversion cases. The conversion does not stop even if it
encounters a NULL byte from the input array.

#include <sys/types.h>
#include <sys/errno.h>
#include <sys/sunddi.h>

:

size_t ret;
char ib[MAXPATHLEN];
char ob[MAXPATHLEN];
size_t il, ol;
int err;

:

/*
* We got the pathname from somewhere.
*
* Calculate the length of input string including the terminating
* NULL byte and prepare other parameters for the conversion.
*/
(void) strlcpy(ib, pathname, MAXPATHLEN);
il = strlen(ib) + 1;
ol = MAXPATHLEN;

/*
* Do the conversion. If the ret > 0, that's the number of
* non-identical character conversions happened during the conversion.
* Regardless of whether we have conversion failure or not,
* outarray could contain some converted characters.
*/
ret = kiconvstr("UTF-8", "ISO-8859-2", ib, &il, ob, &ol,
(KICONV_IGNORE_NULL|KICONV_REPLACE_INVALID), &err);
if (ret == (size_t)-1) {
/* Code conversion not supported? */
if (err == EBADF)
return (-1);

/* Output array too small? */
if (err == E2BIG)
return (-2);

/* Unknown error which isn't possible BTW. */
return (-3);
}

ATTRIBUTES