Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages

  
 
  

home | help
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
       errnum, 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
       returned	by the chdir(2)	system call.  The least	the message will  con-
       tain  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
       decoded.

       This  function  is intended to be used in a fashion similar to the fol-
       lowing 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  argument list.  This will be overwritten by the next
	       call to any libexplain function which shares this  buffer,  in-
	       cluding other threads.

       Note: This function is not thread safe, because it shares a return buf-
       fer 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
       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 fol-
       lowing 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
	       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 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  argument list.  This will be overwritten by the next
	       call to any libexplain function which shares this  buffer,  in-
	       cluding other threads.

       Note: This function is not thread safe, because it shares a return buf-
       fer 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 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 fol-
       lowing 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  re-
	       turned 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
       errnum, const char * pathname);

       The  explain_message_errno_chdir	function is used to obtain an explana-
       tion 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  fol-
       lowing 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 re-
	       turned 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 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)

NAME | SYNOPSIS | DESCRIPTION | COPYRIGHT | AUTHOR

Want to link to this manual page? Use this URL:
<https://www.freebsd.org/cgi/man.cgi?query=explain_chdir&sektion=3&manpath=FreeBSD+12.2-RELEASE+and+Ports>

home | help