NAME

       explain_getdomainname - explain getdomainname(2) errors

SYNOPSIS

       #include <libexplain/getdomainname.h>
       const char *explain_getdomainname(char *data, size_t data_size);
       const char *explain_errno_getdomainname(int errnum, char *data, size_t data_size);
       void explain_message_getdomainname(char *message, int message_size, char *data, size_t data_size);
       void explain_message_errno_getdomainname(char *message, int message_size, int errnum, char *data, size_t
       data_size);

DESCRIPTION

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

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

       The  explain_getdomainname  function  is  used  to  obtain  an  explanation  of  an error returned by the
       getdomainname(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 getdomainname(2) system call.

       data_size
               The original data_size, exactly as passed to the getdomainname(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 (getdomainname(data, data_size) < 0)
              {
                  fprintf(stderr, "%s\n", explain_getdomainname(data, data_size));
                  exit(EXIT_FAILURE);
              }

       The above code example is available pre‐packaged as the explain_getdomainname_or_die(3) function.

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

       The explain_errno_getdomainname function is used to obtain an explanation of an  error  returned  by  the
       getdomainname(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 getdomainname(2) system call.

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

       The above code example is available pre‐packaged as the explain_getdomainname_or_die(3) function.

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

       The  explain_message_getdomainname  function is used to obtain an explanation of an error returned by the
       getdomainname(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 getdomainname(2) system call.

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

       Example: This function is intended to be used in a fashion similar to the following example:
              if (getdomainname(data, data_size) < 0)
              {
                  char message[3000];
                  explain_message_getdomainname(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_getdomainname_or_die(3) function.

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

       The explain_message_errno_getdomainname function is used to obtain an explanation of an error returned by
       the getdomainname(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 getdomainname(2) system call.

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

       Example: This function is intended to be used in a fashion similar to the following example:
              if (getdomainname(data, data_size) < 0)
              {
                  int err = errno;
                  char message[3000];
                  explain_message_errno_getdomainname(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_getdomainname_or_die(3) function.

SEE ALSO

       getdomainname(2)
               get domain name

       explain_getdomainname_or_die(3)
               get domain name and report errors

COPYRIGHT

       libexplain version 1.4
       Copyright (C) 2009 Peter Miller

                                                                                        explain_getdomainname(3)