Provided by: libexplain-dev_1.4.D001-8_amd64 bug

NAME

       explain_telldir - explain telldir(3) errors

SYNOPSIS

       #include <libexplain/telldir.h>
       const char *explain_telldir(DIR *dir);
       const char *explain_errno_telldir(int errnum, DIR *dir);
       void explain_message_telldir(char *message, int message_size, DIR *dir);
       void explain_message_errno_telldir(char *message, int message_size, int errnum, DIR *dir);

DESCRIPTION

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

   explain_telldir
       const char *explain_telldir(DIR *dir);

       The explain_telldir function is used to obtain an explanation of an error returned by  the
       telldir(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.

       dir     The original dir, exactly as passed to the telldir(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:
              off_t result = telldir(dir);
              if (result < 0)
              {
                  fprintf(stderr, "%s\n", explain_telldir(dir));
                  exit(EXIT_FAILURE);
              }

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

   explain_errno_telldir
       const char *explain_errno_telldir(int errnum, DIR *dir);

       The  explain_errno_telldir  function is used to obtain an explanation of an error returned
       by the telldir(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.

       dir     The original dir, exactly as passed to the telldir(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:
              off_t result = telldir(dir);
              if (result < 0)
              {
                  int err = errno;
                  fprintf(stderr, "%s\n", explain_errno_telldir(err, dir));
                  exit(EXIT_FAILURE);
              }

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

   explain_message_telldir
       void explain_message_telldir(char *message, int message_size, DIR *dir);

       The explain_message_telldir function is used to obtain an explanation of an error returned
       by the telldir(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.

       dir     The original dir, exactly as passed to the telldir(3) system call.

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

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

   explain_message_errno_telldir
       void explain_message_errno_telldir(char *message, int message_size, int errnum, DIR *dir);

       The  explain_message_errno_telldir  function  is used to obtain an explanation of an error
       returned by the telldir(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.

       dir     The original dir, exactly as passed to the telldir(3) system call.

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

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

SEE ALSO

       telldir(3)
               return current location in directory stream

       explain_telldir_or_die(3)
               return current location in directory stream and report errors

COPYRIGHT

       libexplain version 1.4
       Copyright (C) 2009 Peter Miller

                                                                               explain_telldir(3)