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explain_symlink(3)	    Library Functions Manual	      explain_symlink(3)

NAME
     explain_symlink - explain symlink(2) errors

SYNOPSIS
     #include <libexplain/symlink.h>
     const char *explain_symlink(const char *oldpath, const char *newpath);
     const  char  *explain_errno_symlink(int  errnum, const char *oldpath, const
     char *newpath);
     void explain_message_symlink(char *message, int  message_size,  const  char
     *oldpath, const char *newpath);
     void explain_message_errno_symlink(char *message, int message_size, int er-
     rnum, const char *oldpath, const char *newpath);

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

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

     The  explain_symlink  function is used to obtain an explanation of an error
     returned by the symlink(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 de-
     coded.

     This function is intended to be used in a fashion similar to the  following
     example:
	    if (symlink(oldpath, rewpath) < 0)
	    {
		fprintf(stderr, '%s0, explain_symlink(oldpath, newpath));
		exit(EXIT_FAILURE);
	    }

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

     newpath
	     The original newpath, exactly as passed to  the  symlink(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 ar-
	     gument list.  This will be overwritten by the next call to any lib-
	     explain 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_symlink
     const  char  *explain_errno_symlink(int  errnum, const char *oldpath, const
     char * newpath);

     The explain_errno_symlink function is used to obtain an explanation  of  an
     error  returned  by the symlink(2) system call.  The least the message will
     contain is the value of strerror(errnum), but usually it will do much  bet-
     ter, and indicate the underlying cause in more detail.

     This  function is intended to be used in a fashion similar to the following
     example:
	    if (symlink(oldpath, newpath) < 0)
	    {
		int err = errno;
		fprintf(stderr, '%s0, explain_errno_symlink(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 nec-
	     essary 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 symlink(2) system
	     call.

     newpath
	     The original newpath, exactly as passed to  the  symlink(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 ar-
	     gument list.  This will be overwritten by the next call to any lib-
	     explain 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_symlink
     void  explain_message_symlink(char  *message,  int message_size, const char
     *oldpath, const char *newpath);

     The explain_message_symlink function is used to obtain an explanation of an
     error returned by the symlink(2) system call.  The least the  message  will
     contain  is  the value of strerror(errno), but usually it will do much bet-
     ter, and indicate the underlying cause in more detail.

     The errno]fP 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 (symlink(oldpath, newpath) < 0)
	    {
		char message[3000];
		explain_message_symlink(message, sizeof(message), oldpath,
		    newpath);
		fprintf(stderr, '%s0, 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.

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

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

   explain_message_errno_symlink
     void explain_message_errno_symlink(char *message, int message_size, int er-
     rnum, const char *oldpath, const char *newpath);

     The explain_message_errno_symlink function is used to obtain an explanation
     of  an error returned by the symlink(2) system call.  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 (symlink(oldpath, newpath) < 0)
     {
	 int err = errno;
	 char message[3000];
	 explain_message_errno_symlink(message, sizeof(message), err,
	     oldpath, newpath);
	 fprintf(stderr, '%s0, 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  nec-
	     essary  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  symlink(2)  system
	     call.

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

COPYRIGHT
     libexplain version 1.3
     Copyright (C) 2008 Peter Miller

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

							      explain_symlink(3)

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