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NAME

       explain_rename - explain rename(2) errors

SYNOPSIS

       #include <libexplain/rename.h>
       const char *explain_rename(const char *oldpath, const char *newpath);
       const char *explain_errno_rename(int errnum, const char *oldpath, const
       char *newpath);
       void explain_message_rename(char *message, int message_size, const char
       *oldpath, const char *newpath);
       void  explain_message_errno_rename(char *message, int message_size, int
       errnum, const char *oldpath, const char *newpath);

DESCRIPTION

       The functions declared in the <libexplain/rename.h> include file may be
       used to explain errors returned by the rename(2) system call.

   explain_rename
       const char *explain_rename(const char *oldpath, const char *newpath);

       The  explain_rename  function  is  used  to obtain an explanation of an
       error returned by the rename(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 (rename(oldpath, rewpath) < 0)
              {
                  fprintf(stderr, "%s\n", explain_rename(oldpath, newpath));
                  exit(EXIT_FAILURE);
              }

       oldpath The original oldpath, exactly as passed to the rename(2) system
               call.

       newpath The original newpath, exactly as passed to the rename(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_errno_rename
       const char *explain_errno_rename(int errnum, const char *oldpath, const
       char *newpath);

       The explain_errno_rename function is used to obtain an  explanation  of
       an  error  returned  by  the rename(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 (rename(oldpath, newpath) < 0)
              {
                  int err = errno;
                  fprintf(stderr, "%s\n", explain_errno_rename(err, oldpath,
                      newpath));
                  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.

       oldpath The original oldpath, exactly as passed to the rename(2) system
               call.   newpath  The original newpath, exactly as passed to the
               rename(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_rename
       void explain_message_rename(char *message, int message_size, const char
       *oldpath, const char *newpath);

       The explain_message_rename function is used to obtain an explanation of
       an  error  returned  by  the rename(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 (rename(oldpath, newpath) < 0)
              {
                  char message[3000];
                  explain_message_rename(message, sizeof(message), oldpath,
                      newpath);
                  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, if the buffer is thread safe.

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

       oldpath The original oldpath, exactly as passed to the rename(2) system
               call.

       newpath The original newpath, exactly as passed to the rename(2) system
               call.

   explain_message_errno_rename
       void explain_message_errno_rename(char *message, int message_size,  int
       errnum, const char *oldpath, const char *newpath);

       The   explain_message_errno_rename   function  is  used  to  obtain  an
       explanation of an error returned by the rename(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 (rename(oldpath, newpath) < 0)
              {
                  int err = errno;
                  char message[3000];
                  explain_message_errno_rename(message, sizeof(message), err,
                      oldpath, newpath);
                  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, given a thread safe buffer.

       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.

       oldpath The original oldpath, exactly as passed to the rename(2) system
               call.

       newpath The original newpath, exactly as passed to the rename(2) system
               call.

COPYRIGHT

       libexplain version
       Copyright (C) 2008 Peter Miller

AUTHOR

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

                                                             explain_rename(3)