libexplain/iconv.h File Reference

explain iconv(3) errors More...

#include <libexplain/gcc_attributes.h>
#include <libexplain/large_file_support.h>
#include <iconv.h>

Go to the source code of this file.

Functions
size_t	explain_iconv_or_die (iconv_t cd, char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft)
size_t	explain_iconv_on_error (iconv_t cd, char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft) LIBEXPLAIN_WARN_UNUSED_RESULT
const char *	explain_iconv (iconv_t cd, char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft) LIBEXPLAIN_WARN_UNUSED_RESULT
const char *	explain_errno_iconv (int errnum, iconv_t cd, char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft) LIBEXPLAIN_WARN_UNUSED_RESULT
void	explain_message_iconv (char *message, int message_size, iconv_t cd, char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft)
void	explain_message_errno_iconv (char *message, int message_size, int errnum, iconv_t cd, char **inbuf, size_t *inbytesleft, char **outbuf, size_t *outbytesleft)

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Detailed Description

explain iconv(3) errors

These functions may be used to obtain explanations for errors returned by the iconv(3) system call.

Definition in file iconv.h.

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Function Documentation

const char* explain_errno_iconv	(	int	errnum,
		iconv_t	cd,
		char **	inbuf,
		size_t *	inbytesleft,
		char **	outbuf,
		size_t *	outbytesleft
	)

The explain_errno_iconv function is used to obtain an explanation of an error returned by the iconv(3) system call. The least the message will contain is the value of strerror(errnum), but usually it will do much better, and indicate the underlying cause in more detail.

Parameters:

errnum	The error value to be decoded, usually obtained from the errno global variable just before this function is called. This is necessary if you need to call any code between the system call to be explained and this function, because many libc functions will alter the value of errno.
cd	The original cd, exactly as passed to the iconv(3) system call.
inbuf	The original inbuf, exactly as passed to the iconv(3) system call.
inbytesleft	The original inbytesleft, exactly as passed to the iconv(3) system call.
outbuf	The original outbuf, exactly as passed to the iconv(3) system call.
outbytesleft	The original outbytesleft, exactly as passed to the iconv(3) system call.

Returns:

The message explaining the error. This message buffer is shared by all libexplain functions which do not supply a buffer in their argument list. This will be overwritten by the next call to any libexplain function which shares this buffer, including other threads.

Note:

This function is not thread safe, because it shares a return buffer across all threads, and many other functions in this library.

Example:

This function is intended to be used in a fashion similar to the following example:

 errno = 0;
 size_t result = iconv(cd, inbuf, inbytesleft, outbuf, outbytesleft);
 if (result < 0 && errno != 0)
 {
     int err = errno;
     fprintf(stderr, "%s\n", explain_errno_iconv(err, cd, inbuf, inbytesleft,
         outbuf, outbytesleft));
     exit(EXIT_FAILURE);
 }

The above code example is available pre-packaged as the explain_iconv_or_die function.

const char* explain_iconv	(	iconv_t	cd,
		char **	inbuf,
		size_t *	inbytesleft,
		char **	outbuf,
		size_t *	outbytesleft
	)

The explain_iconv function is used to obtain an explanation of an error returned by the iconv(3) system call. The least the message will contain is the value of strerror(errno), but usually it will do much better, and indicate the underlying cause in more detail.

The errno global variable will be used to obtain the error value to be decoded.

Parameters:

cd	The original cd, exactly as passed to the iconv(3) system call.
inbuf	The original inbuf, exactly as passed to the iconv(3) system call.
inbytesleft	The original inbytesleft, exactly as passed to the iconv(3) system call.
outbuf	The original outbuf, exactly as passed to the iconv(3) system call.
outbytesleft	The original outbytesleft, exactly as passed to the iconv(3) system call.

Returns:

The message explaining the error. This message buffer is shared by all libexplain functions which do not supply a buffer in their argument list. This will be overwritten by the next call to any libexplain function which shares this buffer, including other threads.

Note:

This function is not thread safe, because it shares a return buffer across all threads, and many other functions in this library.

Example:

This function is intended to be used in a fashion similar to the following example:

 errno = 0;
 size_t result = iconv(cd, inbuf, inbytesleft, outbuf, outbytesleft);
 if (result < 0 && errno != 0)
 {
     explain_output_error_and_die("%s\n", explain_iconv(cd, inbuf,
         inbytesleft, outbuf, outbytesleft));
 }

The above code example is available pre\-packaged as the explain_iconv_or_die function.

size_t explain_iconv_on_error	(	iconv_t	cd,
		char **	inbuf,
		size_t *	inbytesleft,
		char **	outbuf,
		size_t *	outbytesleft
	)

The explain_iconv_on_error function is used to call the iconv(3) system call. On failure an explanation will be printed to stderr, obtained from the explain_iconv(3) function.

Parameters:

cd	The cd, exactly as to be passed to the iconv(3) system call.
inbuf	The inbuf, exactly as to be passed to the iconv(3) system call.
inbytesleft	The inbytesleft, exactly as to be passed to the iconv(3) system call.
outbuf	The outbuf, exactly as to be passed to the iconv(3) system call.
outbytesleft	The outbytesleft, exactly as to be passed to the iconv(3) system call.

Returns:

The value returned by the wrapped iconv(3) system call.

Example:

This function is intended to be used in a fashion similar to the following example:

 errno = 0;
 size_t result = explain_iconv_on_error(cd, inbuf, inbytesleft, outbuf,
     outbytesleft);
 if (result < 0 && errno != 0)
 {
     ...cope with error
     ...no need to print error message
 }

size_t explain_iconv_or_die	(	iconv_t	cd,
		char **	inbuf,
		size_t *	inbytesleft,
		char **	outbuf,
		size_t *	outbytesleft
	)

The explain_iconv_or_die function is used to call the iconv(3) system call. On failure an explanation will be printed to stderr, obtained from the explain_iconv(3) function, and then the process terminates by calling exit(EXIT_FAILURE).

Parameters:

cd	The cd, exactly as to be passed to the iconv(3) system call.
inbuf	The inbuf, exactly as to be passed to the iconv(3) system call.
inbytesleft	The inbytesleft, exactly as to be passed to the iconv(3) system call.
outbuf	The outbuf, exactly as to be passed to the iconv(3) system call.
outbytesleft	The outbytesleft, exactly as to be passed to the iconv(3) system call.

Returns:

This function only returns on success, see iconv(3) for more information. On failure, prints an explanation and exits, it does not return.

Example:

This function is intended to be used in a fashion similar to the following example:

 size_t result = explain_iconv_or_die(cd, inbuf, inbytesleft, outbuf,
     outbytesleft);

void explain_message_errno_iconv	(	char *	message,
		int	message_size,
		int	errnum,
		iconv_t	cd,
		char **	inbuf,
		size_t *	inbytesleft,
		char **	outbuf,
		size_t *	outbytesleft
	)

The explain_message_errno_iconv function is used to obtain an explanation of an error returned by the iconv(3) system call. The least the message will contain is the value of strerror(errnum), but usually it will do much better, and indicate the underlying cause in more detail.

Parameters:

message	The location in which to store the returned message. If a suitable message return buffer is supplied, this function is thread safe.
message_size	The size in bytes of the location in which to store the returned message.
errnum	The error value to be decoded, usually obtained from the errno global variable just before this function is called. This is necessary if you need to call any code between the system call to be explained and this function, because many libc functions will alter the value of errno.
cd	The original cd, exactly as passed to the iconv(3) system call.
inbuf	The original inbuf, exactly as passed to the iconv(3) system call.
inbytesleft	The original inbytesleft, exactly as passed to the iconv(3) system call.
outbuf	The original outbuf, exactly as passed to the iconv(3) system call.
outbytesleft	The original outbytesleft, exactly as passed to the iconv(3) system call.

Example:

This function is intended to be used in a fashion similar to the following example:

 errno = 0;
 size_t result = iconv(cd, inbuf, inbytesleft, outbuf, outbytesleft);
 if (result < 0 && errno != 0)
 {
     int err = errno;
     char message[3000];
     explain_message_errno_iconv(message, sizeof(message), err, cd, inbuf,
         inbytesleft, outbuf, outbytesleft);
     fprintf(stderr, "%s\n", message);
     exit(EXIT_FAILURE);
 }

The above code example is available pre-packaged as the explain_iconv_or_die function.

void explain_message_iconv	(	char *	message,
		int	message_size,
		iconv_t	cd,
		char **	inbuf,
		size_t *	inbytesleft,
		char **	outbuf,
		size_t *	outbytesleft
	)

The explain_message_iconv function is used to obtain an explanation of an error returned by the iconv(3) system call. The least the message will contain is the value of strerror(errnum), but usually it will do much better, and indicate the underlying cause in more detail.

The errno global variable will be used to obtain the error value to be decoded.

Parameters:

message	The location in which to store the returned message. If a suitable message return buffer is supplied, this function is thread safe.
message_size	The size in bytes of the location in which to store the returned message.
cd	The original cd, exactly as passed to the iconv(3) system call.
inbuf	The original inbuf, exactly as passed to the iconv(3) system call.
inbytesleft	The original inbytesleft, exactly as passed to the iconv(3) system call.
outbuf	The original outbuf, exactly as passed to the iconv(3) system call.
outbytesleft	The original outbytesleft, exactly as passed to the iconv(3) system call.

Example:

This function is intended to be used in a fashion similar to the following example:

 errno = 0;
 size_t result = iconv(cd, inbuf, inbytesleft, outbuf, outbytesleft);
 if (result < 0 && errno != 0)
 {
     char message[3000];
     explain_message_iconv(message, sizeof(message), cd, inbuf, inbytesleft,
         outbuf, outbytesleft);
     fprintf(stderr, "%s\n", message);
     exit(EXIT_FAILURE);
 }

The above code example is available pre-packaged as the explain_iconv_or_die function.