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NAME

       explain_timerfd_create - explain timerfd_create(2) errors

SYNOPSIS

       #include <libexplain/timerfd_create.h>
       const char *explain_timerfd_create(int clockid, int flags);
       const char *explain_errno_timerfd_create(int errnum, int clockid, int
       flags);
       void explain_message_timerfd_create(char *message, int message_size,
       int clockid, int flags);
       void explain_message_errno_timerfd_create(char *message, int
       message_size, int errnum, int clockid, int flags);

DESCRIPTION

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

   explain_timerfd_create
       const char *explain_timerfd_create(int clockid, int flags);

       The explain_timerfd_create function is used to obtain an explanation of
       an error returned by the timerfd_create(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.

       clockid The   original   clockid,   exactly   as    passed    to    the
               timerfd_create(2) system call.

       flags   The  original flags, exactly as passed to the timerfd_create(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:
              int result = timerfd_create(clockid, flags);
              if (result < 0)
              {
                  fprintf(stderr, "%s\n", explain_timerfd_create(clockid,
                  flags));
                  exit(EXIT_FAILURE);
              }

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

   explain_errno_timerfd_create
       const char *explain_errno_timerfd_create(int errnum, int clockid, int
       flags);

       The   explain_errno_timerfd_create   function  is  used  to  obtain  an
       explanation of an error returned by the timerfd_create(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.

       clockid The    original    clockid,    exactly   as   passed   to   the
               timerfd_create(2) system call.

       flags   The original flags, exactly as passed to the  timerfd_create(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:
              int result = timerfd_create(clockid, flags);
              if (result < 0)
              {
                  int err = errno;
                  fprintf(stderr, "%s\n", explain_errno_timerfd_create(err,
                  clockid, flags));
                  exit(EXIT_FAILURE);
              }

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

   explain_message_timerfd_create
       void explain_message_timerfd_create(char *message, int message_size,
       int clockid, int flags);

       The  explain_message_timerfd_create  function  is  used  to  obtain  an
       explanation  of an error returned by the timerfd_create(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.

       clockid The   original   clockid,   exactly   as    passed    to    the
               timerfd_create(2) system call.

       flags   The  original flags, exactly as passed to the timerfd_create(2)
               system call.

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

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

   explain_message_errno_timerfd_create
       void explain_message_errno_timerfd_create(char *message, int
       message_size, int errnum, int clockid, int flags);

       The explain_message_errno_timerfd_create function is used to obtain  an
       explanation  of an error returned by the timerfd_create(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.

       clockid The    original    clockid,    exactly   as   passed   to   the
               timerfd_create(2) system call.

       flags   The original flags, exactly as passed to the  timerfd_create(2)
               system call.

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

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

SEE ALSO

       timerfd_create(2)
               timers that notify via file descriptors

       explain_timerfd_create_or_die(3)
               timers that notify via file descriptors and report errors

COPYRIGHT

       libexplain version 0.19
       Copyright (C) 2009 Peter Miller

                                                     explain_timerfd_create(3)