iconv(3C)
NAME
iconv - code conversion function
SYNOPSIS
#include<iconv.h>
size_t iconv(iconv_t cd, const char **inbuf, size_t
*inbytesleft, char **outbuf, size_t *outbytesleft);
DESCRIPTION
The iconv() function converts the sequence of characters
from one code set, in the array specified by inbuf, into a
sequence of corresponding characters in another code set, in
the array specified by outbuf. The code sets are those
specified in the iconv_open() call that returned the conver-
sion descriptor, cd. The inbuf argument points to a variable
that points to the first character in the input buffer and
inbytesleft indicates the number of bytes to the end of the
buffer to be converted. The outbuf argument points to a
variable that points to the first available byte in the out-
put buffer and outbytesleft indicates the number of the
available bytes to the end of the buffer.
For state-dependent encodings, the conversion descriptor cd
is placed into its initial shift state by a call for which
inbuf is a null pointer, or for which inbuf points to a null
pointer. When iconv() is called in this way, and if outbuf
is not a null pointer or a pointer to a null pointer, and
outbytesleft points to a positive value, iconv() will place,
into the output buffer, the byte sequence to change the
output buffer to its initial shift state. If the output
buffer is not large enough to hold the entire reset
sequence, iconv() will fail and set errno to E2BIG. Subse-
quent calls with inbuf as other than a null pointer or a
pointer to a null pointer cause the conversion to take
place from the current state of the conversion descriptor.
If a sequence of input bytes does not form a valid character
in the specified code set, conversion stops after the pre-
vious successfully converted character. If the input buffer
ends with an incomplete character or shift sequence, conver-
sion stops after the previous successfully converted bytes.
If the output buffer is not large enough to hold the entire
converted input, conversion stops just prior to the input
bytes that would cause the output buffer to overflow. The
variable pointed to by inbuf is updated to point to the byte
following the last byte successfully used in the conversion.
The value pointed to by inbytesleft is decremented to
reflect the number of bytes still not converted in the input
buffer. The variable pointed to by outbuf is updated to
point to the byte following the last byte of converted out-
put data. The value pointed to by outbytesleft is
decremented to reflect the number of bytes still available
in the output buffer. For state-dependent encodings, the
conversion descriptor is updated to reflect the shift state
in effect at the end of the last successfully converted
byte sequence.
If iconv() encounters a character in the input buffer that
is legal, but for which an identical character does not
exist in the target code set, iconv() performs an
implementation-defined conversion on this character.
RETURN VALUES
The iconv() function updates the variables pointed to by
the arguments to reflect the extent of the conversion and
returns the number of non-identical conversions performed.
If the entire string in the input buffer is converted, the
value pointed to by inbytesleft will be 0. If the input
conversion is stopped due to any conditions mentioned above,
the value pointed to by inbytesleft will be non-zero and
errno is set to indicate the condition. If an error occurs
iconv() returns (size_t) -1 and sets errno to indicate the
error.
ERRORS
The iconv() function will fail if:
EILSEQ
Input conversion stopped due to an input byte that
does not belong to the input code set.
E2BIG Input conversion stopped due to lack of space in the
output buffer.
EINVAL
Input conversion stopped due to an incomplete charac-
ter or shift sequence at the end of the input buffer.
The iconv() function may fail if:
EBADF
The cd argument is not a valid open conversion
descriptor.
EXAMPLES
Example 1: Using the iconv() Functions
The following example uses the iconv() functions:
#include <stdio.h>
#include <errno.h>
#include <string.h>
#include <iconv.h>
#include <stdlib.h>
/*
* For state-dependent encodings, changes the state of the conversion
* descriptor to initial shift state. Also, outputs the byte sequence
* to change the state to initial state.
* This code is assuming the iconv call for initializing the state
* won't fail due to lack of space in the output buffer.
*/
#define INIT_SHIFT_STATE(cd, fptr, ileft, tptr, oleft) \
{
fptr = NULL; \
ileft = 0; \
tptr = to; \
oleft = BUFSIZ; \
(void) iconv(cd, &fptr, &ileft, &tptr, &oleft); \
(void) fwrite(to, 1, BUFSIZ - oleft, stdout); \
}
int
main(int argc, char **argv)
{
iconv_t cd;
char from[BUFSIZ], to[BUFSIZ];
char *from_code, *to_code;
char *tptr;
const char *fptr;
size_t ileft, oleft, num, ret;
if (argc != 3) {
(void) fprintf(stderr,
"Usage: %s from_codeset to_codeset\\n", argv[0]);
return (1);
}
from_code = argv[1];
to_code = argv[2];
cd = iconv_open((const char *)to_code, (const char *)from_code);
if (cd == (iconv_t)-1) {
/*
* iconv_open failed
*/
(void) fprintf(stderr,
"iconv_open(%s, %s) failed\\n", to_code, from_code);
return (1);
}
ileft = 0;
while ((ileft +=
(num = fread(from + ileft, 1, BUFSIZ - ileft, stdin))) > 0) {
if (num == 0) {
/*
* Input buffer still contains incomplete character
* or sequence. However, no more input character.
*/
/*
* Initializes the conversion descriptor and outputs
* the sequence to change the state to initial state.
*/
INIT_SHIFT_STATE(cd, fptr, ileft, tptr, oleft);
(void) iconv_close(cd);
(void) fprintf(stderr, "Conversion error\\n");
return (1);
}
fptr = from;
for (;;) {
tptr = to;
oleft = BUFSIZ;
ret = iconv(cd, &fptr, &ileft, &tptr, &oleft);
if (ret != (size_t)-1) {
/*
* iconv succeeded
*/
/*
* Outputs converted characters
*/
(void) fwrite(to, 1, BUFSIZ - oleft, stdout);
break;
}
/*
* iconv failed
*/
if (errno == EINVAL) {
/*
* Incomplete character or shift sequence
*/
/*
* Outputs converted characters
*/
(void) fwrite(to, 1, BUFSIZ - oleft, stdout);
/*
* Copies remaining characters in input buffer
* to the top of the input buffer.
*/
(void) memmove(from, fptr, ileft);
/*
* Tries to fill input buffer from stdin
*/
break;
} else if (errno == E2BIG) {
/*
* Lack of space in output buffer
*/
/*
* Outputs converted characters
*/
(void) fwrite(to, 1, BUFSIZ - oleft, stdout);
/*
* Tries to convert remaining characters in
* input buffer with emptied output buffer
*/
continue;
} else if (errno == EILSEQ) {
/*
* Illegal character or shift sequence
*/
/*
* Outputs converted characters
*/
(void) fwrite(to, 1, BUFSIZ - oleft, stdout);
/*
* Initializes the conversion descriptor and
* outputs the sequence to change the state to
* initial state.
*/
INIT_SHIFT_STATE(cd, fptr, ileft, tptr, oleft);
(void) iconv_close(cd);
(void) fprintf(stderr,
"Illegal character or sequence\\n");
return (1);
} else if (errno == EBADF) {
/*
* Invalid conversion descriptor.
* Actually, this shouldn't happen here.
*/
(void) fprintf(stderr, "Conversion error\\n");
return (1);
} else {
/*
* This errno is not defined
*/
(void) fprintf(stderr, "iconv error\\n");
return (1);
}
}
}
/*
* Initializes the conversion descriptor and outputs
* the sequence to change the state to initial state.
*/
INIT_SHIFT_STATE(cd, fptr, ileft, tptr, oleft);
(void) iconv_close(cd);
return (0);
}
FILES
/usr/lib/iconv/*.so
conversion modules
/usr/lib/iconv/sparcv9/*.so
conversion modules
/usr/lib/iconv/geniconvtbl/binarytables/*.bt
conversion binary tables
ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:
____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| MT-Level | MT-Safe |
|_____________________________|_____________________________|
SEE ALSO
geniconvtbl(1), iconv(1), iconv_close(3C), iconv_open(3C),
geniconvtbl(4), attributes(5), iconv(5), iconv_unicode(5)
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