explain_iconv_open(3)

NAME
explain_iconv_open - explain iconv_open(3) errors

SYNOPSIS
#include <libexplain/iconv_open.h>

const char *explain_iconv_open(const char *tocode, const char *fromcode);
const char *explain_errno_iconv_open(int errnum, const char *tocode, const char *fromcode);
void explain_message_iconv_open(char *message, int message_size, const char *tocode, const char *fromcode);
void explain_message_errno_iconv_open(char *message, int message_size, int errnum, const char *tocode, const char *fromcode);

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

  explain_iconv_open
const char *explain_iconv_open(const char *tocode, const char *fromcode);

The explain_iconv_open function is used to obtain an explanation of an error returned by the iconv_open(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.

tocode
    The original tocode, exactly as passed to the iconv_open(3) system call.

fromcode
    The original fromcode, exactly as passed to the iconv_open(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:
    iconv_t result = iconv_open(tocode, fromcode);
    if (result < 0)
    {
    fprintf(stderr, "%s\n", explain_iconv_open(tocode, fromcode));
        exit(EXIT_FAILURE);
    }

The above code example is available pre-packaged as the explain_iconv_open_or_die(3) function.

  explain_errno_iconv_open
const char *explain_errno_iconv_open(int errnum, const char *tocode, const char *fromcode);

The explain_errno_iconv_open function is used to obtain an explanation of an error returned by the iconv_open(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.

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.

tocode
    The original tocode, exactly as passed to the iconv_open(3) system call.

fromcode
    The original fromcode, exactly as passed to the iconv_open(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:
    iconv_t result = iconv_open(tocode, fromcode);
    if (result < 0)
    {
        int err = errno;
    fprintf(stderr, "%s\n", explain_errno_iconv_open(err, tocode, fromcode));
        exit(EXIT_FAILURE);
    }

The above code example is available pre-packaged as the explain_iconv_open_or_die(3) function.

  explain_message_iconv_open
void explain_message_iconv_open(char *message, int message_size, const char *tocode, const char *fromcode);

The explain_message_iconv_open function is used to obtain an explanation of an error returned by the iconv_open(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.

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.

tocode
    The original tocode, exactly as passed to the iconv_open(3) system call.

fromcode
    The original fromcode, exactly as passed to the iconv_open(3) system call.

Example: This function is intended to be used in a fashion similar to the following example:
    iconv_t result = iconv_open(tocode, fromcode);
    if (result < 0)
    {
        char message[3000];
    explain_message_iconv_open(message, sizeof(message), tocode, fromcode);
        fprintf(stderr, "%s\n", message);
        exit(EXIT_FAILURE);
    }

The above code example is available pre-packaged as the explain_iconv_open_or_die(3) function.

  explain_message_errno_iconv_open
void explain_message_errno_iconv_open(char *message, int message_size, int errnum, const char *tocode, const char *fromcode);

The explain_message_errno_iconv_open function is used to obtain an explanation of an error returned by the iconv_open(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.

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.

tocode
    The original tocode, exactly as passed to the iconv_open(3) system call.

fromcode
    The original fromcode, exactly as passed to the iconv_open(3) system call.

Example: This function is intended to be used in a fashion similar to the following example:
    iconv_t result = iconv_open(tocode, fromcode);
    if (result < 0)
    {
        int err = errno;
        char message[3000];
    explain_message_errno_iconv_open(message, sizeof(message), err, tocode, fromcode);
        fprintf(stderr, "%s\n", message);
        exit(EXIT_FAILURE);
    }

The above code example is available pre-packaged as the explain_iconv_open_or_die(3) function.

SEE ALSO

iconv_open(3)
    allocate descriptor for character set conversion

explain_iconv_open_or_die(3)
    allocate descriptor for character set conversion and report errors

COPYRIGHT
libexplain version
Copyright (C) 2013 Peter Miller