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explain_chdir(3)	    Library Functions Manual		explain_chdir(3)

NAME
     explain_chdir - explain chdir(2) errors

SYNOPSIS
     #include <libexplain/chdir.h>
     const char *explain_chdir(const char *pathname);
     void  explain_message_chdir(char  *message,  int  message_size,  const char
     *pathname);
     const char *explain_errno_chdir(int errnum, const char *pathname);
     void explain_message_errno_chdir(char *message, int message_size,	int  er-
     rnum, const char *pathname);

DESCRIPTION
     These function may be used to obtain explanations of chdir(2) errors.

   explain_chdir
     const char *explain_chdir(const char *pathname);

     The explain_chdir function is used to obtain an explanation of an error re-
     turned  by the chdir(2) system call.  The least the message will contain is
     the value of strerror(errno), but usually it will do much better, and indi-
     cate 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 (chdir(pathname) < 0)
	    {
		fprintf(stderr, '%s0, explain_chdir(pathname));
		exit(EXIT_FAILURE);
	    }

     pathname
	     The original pathname, exactly as passed  to  the	chdir(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_chdir
     const char *explain_errno_chdir(int errnum, const char *pathname);

     The explain_errno_chdir function is used to obtain an explanation of an er-
     ror  returned by the chdir(2) system call.  The least the message will con-
     tain 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 (chdir(pathname) < 0)
	    {
		int err = errno;
		fprintf(stderr, '%s0, explain_errno_chdir(err, pathname));
		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.

     pathname
	     The  original  pathname,  exactly	as passed to the chdir(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_chdir
     void explain_message_chdir(char  *message,  int  message_size,  const  char
     *pathname);

     The  explain_message_chdir  function is used to obtain an explanation of an
     error returned by the chdir(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 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 (chdir(pathname) < 0)
	    {
		char message[3000];
		explain_message_chdir(message, sizeof(message), pathname);
		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.

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

   explain_message_errno_chdir
     void explain_message_errno_chdir(char *message, int message_size,	int  er-
     rnum, const char * pathname);

     The  explain_message_errno_chdir  function is used to obtain an explanation
     of an error returned by the chdir(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 (chdir(pathname) < 0)
	    {
		int err = errno;
		char message[3000];
		explain_message_errno_chdir(message, sizeof(message), err,
		    pathname);
		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.

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

COPYRIGHT
     libexplain version 1.3
     Copyright (C) 2008 Peter Miller

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

								explain_chdir(3)

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