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NAME

       explain_setdomainname - explain setdomainname(2) errors

SYNOPSIS

       #include <libexplain/setdomainname.h>
       const char *explain_setdomainname(const char *data, size_t data_size);
       const char *explain_errno_setdomainname(int errnum, const char *data,
       size_t data_size);
       void explain_message_setdomainname(char *message, int message_size,
       const char *data, size_t data_size);
       void explain_message_errno_setdomainname(char *message, int
       message_size, int errnum, const char *data, size_t data_size);

DESCRIPTION

       These functions may be used to obtain explanations for errors  returned
       by the setdomainname(2) system call.

   explain_setdomainname
       const char *explain_setdomainname(const char *data, size_t data_size);

       The  explain_setdomainname function is used to obtain an explanation of
       an error returned by the setdomainname(2) 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.

       data    The original data, exactly as passed  to  the  setdomainname(2)
               system call.

       data_size
               The    original   data_size,   exactly   as   passed   to   the
               setdomainname(2) 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:
              if (setdomainname(data, data_size) < 0)
              {
                  fprintf(stderr, "%s\n", explain_setdomainname(data,
                  data_size));
                  exit(EXIT_FAILURE);
              }

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

   explain_errno_setdomainname
       const char *explain_errno_setdomainname(int errnum, const char *data,
       size_t data_size);

       The   explain_errno_setdomainname   function   is  used  to  obtain  an
       explanation of an error returned by the setdomainname(2)  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.

       data    The  original  data,  exactly as passed to the setdomainname(2)
               system call.

       data_size
               The   original   data_size,   exactly   as   passed   to    the
               setdomainname(2) 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:
              if (setdomainname(data, data_size) < 0)
              {
                  int err = errno;
                  fprintf(stderr, "%s\n", explain_errno_setdomainname(err,
                  data, data_size));
                  exit(EXIT_FAILURE);
              }

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

   explain_message_setdomainname
       void explain_message_setdomainname(char *message, int message_size,
       const char *data, size_t data_size);

       The  explain_message_setdomainname  function  is  used  to  obtain   an
       explanation  of  an error returned by the setdomainname(2) 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.

       data    The original data, exactly as passed  to  the  setdomainname(2)
               system call.

       data_size
               The    original   data_size,   exactly   as   passed   to   the
               setdomainname(2) system call.

       Example: This function is intended to be used in a fashion  similar  to
       the following example:
              if (setdomainname(data, data_size) < 0)
              {
                  char message[3000];
                  explain_message_setdomainname(message, sizeof(message),
                  data, data_size);
                  fprintf(stderr, "%s\n", message);
                  exit(EXIT_FAILURE);
              }

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

   explain_message_errno_setdomainname
       void explain_message_errno_setdomainname(char *message, int
       message_size, int errnum, const char *data, size_t data_size);

       The explain_message_errno_setdomainname function is used to  obtain  an
       explanation  of  an error returned by the setdomainname(2) 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.

       data    The  original  data,  exactly as passed to the setdomainname(2)
               system call.

       data_size
               The   original   data_size,   exactly   as   passed   to    the
               setdomainname(2) system call.

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

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

SEE ALSO

       setdomainname(2)
               set domain name

       explain_setdomainname_or_die(3)
               set domain name and report errors

COPYRIGHT

       libexplain version 0.19
       Copyright (C) 2009 Peter Miller

                                                      explain_setdomainname(3)