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NAME

       explain_tcdrain - explain tcdrain(3) errors

SYNOPSIS

       #include <libexplain/tcdrain.h>
       const char *explain_tcdrain(int fildes);
       const char *explain_errno_tcdrain(int errnum, int fildes);
       void explain_message_tcdrain(char *message, int message_size, int
       fildes);
       void explain_message_errno_tcdrain(char *message, int message_size, int
       errnum, int fildes);

DESCRIPTION

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

   explain_tcdrain
       const char *explain_tcdrain(int fildes);

       The explain_tcdrain function is used to obtain  an  explanation  of  an
       error  returned  by  the  tcdrain(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.

       fildes  The original fildes, exactly as passed to the tcdrain(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:
              if (tcdrain(fildes) < 0)
              {
                  fprintf(stderr, "%s\n", explain_tcdrain(fildes));
                  exit(EXIT_FAILURE);
              }

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

   explain_errno_tcdrain
       const char *explain_errno_tcdrain(int errnum, int fildes);

       The explain_errno_tcdrain function is used to obtain an explanation  of
       an  error returned by the tcdrain(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.

       fildes  The original fildes, exactly as passed to the tcdrain(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:
              if (tcdrain(fildes) < 0)
              {
                  int err = errno;
                  fprintf(stderr, "%s\n", explain_errno_tcdrain(err, fildes));
                  exit(EXIT_FAILURE);
              }

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

   explain_message_tcdrain
       void explain_message_tcdrain(char *message, int message_size, int
       fildes);

       The  explain_message_tcdrain  function is used to obtain an explanation
       of an error returned by the  tcdrain(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.

       fildes  The original fildes, exactly as passed to the tcdrain(3) system
               call.

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

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

   explain_message_errno_tcdrain
       void explain_message_errno_tcdrain(char *message, int message_size, int
       errnum, int fildes);

       The   explain_message_errno_tcdrain  function  is  used  to  obtain  an
       explanation of an error returned by the  tcdrain(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.

       fildes  The original fildes, exactly as passed to the tcdrain(3) system
               call.

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

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

SEE ALSO

       tcdrain(3)
               Execute tcdrain(3)

       explain_tcdrain_or_die(3)
               Execute tcdrain(3) and report errors

COPYRIGHT

       libexplain version 0.19
       Copyright (C) 2009 Peter Miller,,,

                                                            explain_tcdrain(3)