iconv(3)iconv(3)NAMEiconv - Convert a string of characters from one codeset to another
codeset
SYNOPSIS
The following syntax is for pre-XSH5.0-compliant interfaces on Tru64
UNIX V4 and V5 systems: #include <iconv.h>
size_t iconv(
iconv_t cd,
const char **inbuf,
size_t *inbytesleft,
char **outbuf,
size_t *outbytesleft );
The following syntax is for pre-V4 Tru64 UNIX systems and XSH5.0-com‐
pliant interfaces on V5 systems: #include <iconv.h>
size_t iconv(
iconv_t cd,
char **inbuf,
size_t *inbytesleft,
char **outbuf,
size_t *outbytesleft );
LIBRARY
The iconv library (libiconv)
STANDARDS
Interfaces documented on this reference page conform to industry stan‐
dards as follows:
iconv(): XSH4.0, XSH4.2, XSH5.0
Refer to the standards(5) reference page for more information about
industry standards and associated tags.
PARAMETERS
Specifies the conversion descriptor that points to the correct codeset
converter Points to a variable that points to the beginning of a buffer
that contains the characters to be converted Points to an integer that
contains the number of bytes in inbuf still to be converted Points to a
variable that points to the buffer that contains the characters that
have been converted Points to an integer that contains the number of
free bytes in outbuf
DESCRIPTION
The iconv() function converts a string of characters in inbuf into a
different codeset and returns the results in outbuf. The required con‐
verter is identified by cd, which must be a valid descriptor returned
by a previous successful call to the iconv_open() function.
On calling, the inbytesleft parameter indicates the number of bytes in
inbuf to be converted and outbytesleft indicates the number of avail‐
able bytes in outbuf.
For codesets that include shift-state sequences, a call to iconv() in
which inbuf is or points to a null pointer places the cd conversion
descriptor into its initial shift state. In this case, as long as out‐
buf is not (or does not point to) a null pointer, the call places in
outbuf the byte sequence that changes the output buffer to its initial
shift state. If the output buffer is not large enough to hold the
entire reset sequence, the call fails and sets errno to [E2BIG]. Any
subsequent calls in which inbuf is not (or does not point to) a null
pointer cause the conversion to take place from the current state of
the conversion descriptor. See the RESTRICTIONS section for information
about support of shift-state encoding.
If a sequence of input bytes does not form a character that is valid in
the input codeset, conversion stops after the previous successfully
converted character. If the input buffer ends with an incomplete char‐
acter or shift sequence, conversion stops after the last byte sequence
that was successfully converted to a character. If the output is not
large enough to hold the entire sequence of converted characters, con‐
version stops just prior to the input byte sequence that would cause
the output buffer to overflow.
On return from the call: The inbuf value is updated to point to the
byte following the last byte used successfully in conversion The
inbytesleft value is decremented to reflect the number of input bytes
still not converted The outbuf value is updated to point to the byte
following the last output byte of successfully converted data The out‐
bytesleft value is decremented to reflect the number of bytes still
available in the output buffer. For codesets that include shift-state
encoding, the conversion descriptor is updated to reflect the shift
state in effect at the end of the last successfully converted byte
sequence.
It is possible for input data to include a character that is valid in
the input codeset but for which an identical character does not exist
in the output codeset. The output character for such cases is defined
by the converter that iconv() applies when converting from one particu‐
lar codeset to another. In other words, the output character in this
case can vary from one codeset converter to another.
RESTRICTIONS
Currently, the operating system does not include locales whose codesets
use shift-state encoding. Some sections of this reference page refer
to iconv() behavior with respect to conversion of shift sequences. This
information is included only for your convenience in developing porta‐
ble applications that run on multiple platforms, some of which may sup‐
ply locales whose codesets do use shift-state encoding.
RETURN VALUES
The iconv() function updates the variables pointed to by the call argu‐
ments to reflect the extent of the conversion and returns the number of
non-identical conversions performed. If the function is successful and
converts the entire input string, the value pointed to by inbytesleft
will be 0 (zero).
If an error occurs, the function returns (size_t)-1 and sets errno to
indicate the condition.
ERRORS
If any of the following conditions occur, the iconv() function sets
errno to the corresponding value: The outbuf buffer is too small to
contain all the converted characters. The character that causes the
overflow is not converted and inbytesleft indicates the bytes left to
be converted, including the character that caused the overflow. The
inbuf parameter points to the first byte of the characters left to con‐
vert. The cd parameter does not specify a valid converter descriptor.
An input character does not belong to the input codeset. No conversion
is attempted on the invalid character and inbytesleft indicates the
bytes left to be converted, including the first byte of the invalid
character. The inbuf parameter points to the first byte of the invalid
character sequence.
The values of outbuf and outbytesleft are updated according to
the number of characters that were previously converted. The
last character or shift sequence in the inbuf parameter was not
complete. The inbytesleft parameter indicates the number of
input bytes still not converted.
SEE ALSO
Functions: iconv_close(3), iconv_open(3)
Commands: iconv(1), genxlt(1)
Others: iconv_intro(5), standards(5)iconv(3)