iconv(3) [redhat man page]
ICONV(3) Linux Programmer's Manual ICONV(3) NAME
iconv - perform character set conversion SYNOPSIS
#include <iconv.h> size_t iconv(iconv_t cd, char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft); DESCRIPTION
The argument cd must be a conversion descriptor created using the function iconv_open. The main case is when inbuf is not NULL and *inbuf is not NULL. In this case, the iconv function converts the multibyte sequence starting at *inbuf to a multibyte sequence starting at *outbuf. At most *inbytesleft bytes, starting at *inbuf, will be read. At most *out- bytesleft bytes, starting at *outbuf, will be written. The iconv function converts one multibyte character at a time, and for each character conversion it increments *inbuf and decrements *inbytesleft by the number of converted input bytes, it increments *outbuf and decrements *outbytesleft by the number of converted output bytes, and it updates the conversion state contained in cd. The conversion can stop for four reasons: 1. 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. 2. The input byte sequence has been entirely converted, i.e. *inbytesleft has gone down to 0. In this case iconv returns the number of non- reversible conversions performed during this call. 3. 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. 4. 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 iconv function attempts to set cd's conversion state to the initial state and store a corresponding shift sequence at *outbuf. At most *outbytesleft 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 *outbytesleft 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 iconv function sets cd's conversion state to the initial state. RETURN VALUE
The iconv function returns the number of characters converted in a non-reversible way during this call; reversible conversions are not counted. In case of error, it sets errno and returns (size_t)(-1). ERRORS
The following errors can occur, among others: E2BIG There is not sufficient room at *outbuf. EILSEQ An invalid multibyte sequence has been encountered in the input. EINVAL An incomplete multibyte sequence has been encountered in the input. CONFORMING TO
UNIX98 SEE ALSO
iconv_open(3), iconv_close(3) GNU
2001-11-15 ICONV(3)
Check Out this Related Man Page
iconv(3) Library Functions Manual iconv(3) NAME
iconv - Converts a string of characters from one codeset to another codeset LIBRARY
The iconv library (libiconv) SYNOPSIS
#include <iconv.h> size_t iconv( iconv_t cd, const char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft); The following nonstandard interface is supported in libiconv only for compatibility with versions of DIGITAL UNIX earlier than Version 4.0: size_t iconv( iconv_t cd, char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft); STANDARDS
Interfaces documented on this reference page conform to industry standards as follows: iconv(): 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 available 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 outbuf 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 informa- tion 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 character 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, conversion 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 outbytesleft 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 par- ticular 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 devel- oping portable applications that run on multiple platforms, some of which may supply locales whose codesets do use shift-state encoding. RETURN VALUES
The iconv() function updates the variables pointed to by the call arguments 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 conver- sion 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. RELATED INFORMATION
Functions: iconv_close(3), iconv_open(3) Commands: iconv(1), genxlt(1) Others: iconv_intro(5), standards(5) delim off iconv(3)