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NAME

       explain_stat - explain stat(2) errors

SYNOPSIS

       #include <libexplain/stat.h>
       const char *explain_stat(const char *pathname, const struct stat *buf);
       void explain_message_stat(char *message, int message_size,  const  char
       *pathname, const struct stat *buf);
       const  char *explain_errno_stat(int errnum, const char *pathname, const
       struct stat *buf);
       void explain_message_errno_stat(char *message,  int  message_size,  int
       errnum, const char *pathname, const struct stat *buf);

DESCRIPTION

       These functions may be used to obtain explanations for stat(2) errors .

   explain_errno_stat
       const char *explain_errno_stat(int errnum, const char *pathname,  const
       struct stat *buf);

       The  explain_errno_stat function is used to obtain an explanation of an
       error returned by the stat(2) function.  The  least  the  message  will
       contain  is  the value of strerror(errnum), but usually it will do much
       better, and indicate the underlying cause in more detail.

       This function is intended to be  used  in  a  fashion  similar  to  the
       following example:
              if (stat(pathname, &buf) < 0)
              {
                  int err = errno;
                  fprintf(stderr, "%s\n", explain_errno_stat(err, pathname, &buf));
                  exit(EXIT_FAILURE);
              }

       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.

       pathname
               The  original pathname, exactly as passed to the stat(2) system
               call.

       buf     The original buf, exactly as passed to the stat(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.

   explain_message_errno_stat
       void explain_message_errno_stat(char *message,  int  message_size,  int
       errnum, const char *pathname, const struct stat *buf);

       The   explain_message_errno_stat   function   is   used  to  obtain  an
       explanation of an error returned by the stat(2)  function.   The  least
       the  message will contain is the value of strerror(errnum), but usually
       it will do much better, and  indicate  the  underlying  cause  in  more
       detail.

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

       message The location in which to store the returned message.  Because a
               message  return  buffer  has  been  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.

       pathname
               The  original pathname, exactly as passed to the stat(2) system
               call.

       buf     The original buf, exactly as passed to the stat(2) system call.

   explain_message_stat
       void  explain_message_stat(char  *message, int message_size, const char
       *pathname, const struct stat *buf);

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

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

       message The location in which to store the returned message.  Because a
               message return buffer  has  been  supplied,  this  function  is
               thread safe.

       message_size
               The  size  in  bytes  of  the  location  in  which to store the
               returned message.

       pathname
               The original pathname, exactly as passed to the stat(2)  system
               call.

       buf     The original buf, exactly as passed to the stat(2) system call.

   explain_stat
       const char *explain_stat(const char  *pathname,  const  struct  stat  *
       buf);

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

       This  function  is  intended  to  be  used  in a fashion similar to the
       following example:
              if (stat(pathname, &buf) < 0)
              {
                  fprintf(stderr, "%s\n", explain_stat(pathname, &buf));
                  exit(EXIT_FAILURE);
              }

       pathname
               The original pathname, exactly as passed to the stat(2)  system
               call.

       buf     The original buf, exactly as passed to the stat(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.

COPYRIGHT

       libexplain version
       Copyright (C) 2008 Peter Miller

AUTHOR

       Written by Peter Miller <pmiller@opensource.org.au>

                                                               explain_stat(3)