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NAME

       explain_pathconf - explain pathconf(3) errors

SYNOPSIS

       #include <libexplain/pathconf.h>
       const char *explain_pathconf(const char *pathname, int name);
       const  char  *explain_errno_pathconf(int  errnum, const char *pathname,
       int name);
       void explain_message_pathconf(char *message,  int  message_size,  const
       char *pathname, int name);
       void  explain_message_errno_pathconf(char  *message,  int message_size,
       int errnum, const char *pathname, int name);

DESCRIPTION

       These functions may be used to obtain explanations for errors  returned
       by the pathconf(3) system call.

   explain_pathconf
       const char *explain_pathconf(const char *pathname, int name);

       The  explain_pathconf  function  is used to obtain an explanation of an
       error returned by the pathconf(3) 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
       following example:
              if (pathconf(pathname, name) < 0)
              {
                  fprintf(stderr, "%s\n", explain_pathconf(pathname, name));
                  exit(EXIT_FAILURE);
              }

       The   above   code   example   is   available   pre-packaged   as   the
       explain_pathconf_or_die(3) function.

       pathname
               The  original  pathname,  exactly  as passed to the pathconf(3)
               system call.

       name    The original name, exactly as passed to the pathconf(3)  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_pathconf
       const char *explain_errno_pathconf(int errnum,  const  char  *pathname,
       int name);

       The explain_errno_pathconf function is used to obtain an explanation of
       an error returned by  the  pathconf(3)  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 (pathconf(pathname, name) < 0)
              {
                  int err = errno;
                  fprintf(stderr, "%s\n", explain_errno_pathconf(err, pathname, name));
                  exit(EXIT_FAILURE);
              }

       The   above   code   example   is   available   pre-packaged   as   the
       explain_pathconf_or_die(3) function.

       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 pathconf(3)
               system call.

       name    The original name, exactly as passed to the pathconf(3)  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_pathconf
       void explain_message_pathconf(char *message,  int  message_size,  const
       char *pathname, int name);

       The  explain_message_pathconf  function  may  be  used  to   obtain  an
       explanation of an error returned by the pathconf(3) 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
       following example:
              if (pathconf(pathname, name) < 0)
              {
                  char message[3000];
                  explain_message_pathconf(message, sizeof(message), pathname, name);
                  fprintf(stderr, "%s\n", message);
                  exit(EXIT_FAILURE);
              }

       The   above   code   example   is   available   pre-packaged   as   the
       explain_pathconf_or_die(3) function.

       message The location in which to store  the  returned  message.   If  a
               suitable  message  return  buffer is 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 pathconf(3)
               system call.

       name    The original name, exactly as passed to the pathconf(3)  system
               call.

   explain_message_errno_pathconf
       void  explain_message_errno_pathconf(char  *message,  int message_size,
       int errnum, const char *pathname, int name);

       The explain_message_errno_pathconf function may be used  to  obtain  an
       explanation  of  an error returned by the pathconf(3) 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 (pathconf(pathname, name) < 0)
              {
                  int err = errno;
                  char message[3000];
                  explain_message_errno_pathconf(message, sizeof(message), err,
                      pathname, name);
                  fprintf(stderr, "%s\n", message);
                  exit(EXIT_FAILURE);
              }

       The   above   code   example   is   available   pre-packaged   as   the
       explain_pathconf_or_die(3) function.

       message The location in which to store  the  returned  message.   If  a
               suitable  message  return  buffer is 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 pathconf(3)
               system call.

       name    The original name, exactly as passed to the pathconf(3)  system
               call.

SEE ALSO

       pathconf(3)
               get configuration values for files

       explain_pathconf_or_die(3)
               get configuration values for files and report errors

COPYRIGHT

       libexplain version 0.19
       Copyright (C) 2008 Peter Miller

                                                           explain_pathconf(3)