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manual page for my new Dpathconf()



NAME
     Dpathconf - get information about file system configuration

SYNOPSIS
     LONG Dpathconf( char *name, WORD mode );

DESCRIPTION
     Dpathconf returns information about various limits or  capa-
     bilities  of the file system containing the file named name.
     The variable mode controls  which  limit  or  capability  is
     being queried, as follows:

     mode               value returned

     -1                 max. legal value for n in Dpathconf(n)
     DP_IOPEN (0)       internal limit on the number of open files
     DP_MAXLINKS (1)    maximum number of links to a file
     DP_PATHMAX (2)     maximum length of a full path name
     DP_NAMEMAX (3)     maximum length of an individual file name
     DP_ATOMIC (4)      number of bytes that can be written atomically
     DP_TRUNC (5)       information about file name truncation
     DP_CASE (6)        information about case sensitivity
     DP_MODEATTR (7)    information about supported file mode bits
     DP_XATTRFIELDS (8) information about supported extended attributes

     If any of these items are  unlimited,  then  0x7fffffffL  is
     returned.

     For DP_TRUNC (mode 5), return information  about  file  name
     truncation, the returned value has the following meaning:

     0    (DP_NOTRUNC) File names are  never  truncated;  if  the
          file  name  in any system call affecting this directory
          exceeds the maximum length (returned by mode  3),  then
          the  error  value  ERANGE  is returned from that system
          call.

     1    (DP_AUTOTRUNC) File names are  automatically  truncated
          to the maximum length.

     2    (DP_DOSTRUNC) File names are truncated according to DOS
          rules,  i.e.  to  a maximum 8 character base name and a
          maximum 3 character extension.

     For DP_CASE (mode 6), information  about  case  sensitivity,
     the returned value has the following meaning:

     0    (DP_CASESENS) File system is case sensitive.

     1    (DP_CASECON) File system is case insensitive, and  file
          case  information is not preserved (e.g. file names are
          always converted to upper case).

     2    (DP_CASEINSENS) File system is  case  insensitive,  but
          file names are saved with the case they were originally
          given (e.g. file "FooBar" will appear in the  directory
          under  that  name,  and may be accessed as "foobar" and
          "fOObaR", etc.).

     For DP_MODEATTR (mode 7), information about the validity  of
     fields  in the mode and attrib fields of the XATTR structure
     is returned. Bits 0..5 contain flags about what field of the
     attr field is valid:

     FA_RDONLY (0x01): only set when read permission  is  handled
     by  this  bit,  not when it is emulated by means of the mode
     bits.

     FA_HIDDEN (0x02), FA_SYSTEM (0x04): set when the  filesystem
     supports   these   special  attributes  (normally  only  DOS
     filesystems).

     FA_LABEL (0x08):  set  when  the  filesystem  label  can  be
     retrieved with Fsfirst/Fsnext.

     FA_DIR (0x10): reserved. Use the file type bits (see  below)
     to inquire whether there are folders on the filesystem.

     FA_CHANGED (0x20): set if the filesystem supports the notion
     of an archive flag and uses the attr field for that.

     Bits 6 and 7 are reserved. Bits 8..19 contain flags describ-
     ing  the  validity  of  the lower 12 bits of the mode field.
     Bits 20..27 contain flags about what types of files are sup-
     ported on this filesystem:

     DP_FT_DIR   (0x00100000L)  directories (always if . is there)
     DP_FT_CHR   (0x00200000L)  character special files
     DP_FT_BLK   (0x00400000L)  block special files, currently unused
     DP_FT_REG   (0x00800000L)  regular files
     DP_FT_LNK   (0x01000000L)  symbolic links
     DP_FT_SOCK  (0x02000000L)  sockets, currently unused
     DP_FT_FIFO  (0x04000000L)  pipes
     DP_FT_MEM   (0x08000000L)  shared memory or proc files

     Bits 28..31 are reserved.

     For DP_XATTRFIELDS (mode 8), a bit mask of supported  fields
     in  the  XATTR  structure  is  returned  (all other bits are
     reserved):

     DP_INDEX    (0x0001)    index field unique for every file on the fs
     DP_DEV      (0x0002)    device field valid
     DP_RDEV     (0x0004)    rdev field valid (and not identical to dev)
     DP_NLINK    (0x0008)    number of links valid
     DP_UID      (0x0010)    user id valid
     DP_GID      (0x0020)    group id valid
     DP_BLKSIZE  (0x0040)    block size valid
     DP_SIZE     (0x0080)    size field valid (and meaningful!)
     DP_NBLOCKS  (0x0100)    number of blocks valid
     DP_ATIME    (0x0200)    file system has last access time
     DP_CTIME    (0x0400)    file system has last status change time
     DP_MTIME    (0x0800)    file system has last modification time


EXAMPLES
     DP_MODEATTR could be used by a graphical program that  mani-
     pulates the file's attributes: it could automagically detect
     which fields to display.

     You can use DP_XATTRFIELD to find out which type  of  times-
     tamp  is  maintained  on  a filesystem. Example: the process
     file system returns the creation time for all timestamps, so
     none of the time fields in the mask will be set.

SEE ALSO
     Sysconf(2)

-- 
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Julian F. Reschke, Hensenstr. 142, D-48161 Muenster
 eMail: reschke@math.uni-muenster.de jr@ms.maus.de
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