GETDIRENTRIES(2)          OpenBSD Programmer's Manual         GETDIRENTRIES(2)

NAME
     getdirentries - get directory entries in a filesystem independent format



SYNOPSIS
     #include <dirent.h>

     int
     getdirentries(int fd, char *buf, int nbytes, long *basep);

DESCRIPTION
     getdirentries() reads directory entries from the directory referenced by
     the file descriptor fd into the buffer pointed to by buf, in a filesystem
     independent format.  Up to nbytes of data will be transferred.  nbytes
     must be greater than or equal to the block size associated with the file,
     see stat(2).  Some filesystems may not support getdirentries() with
     buffers smaller than this size.

     The data in the buffer is a series of dirent structures each containing
     the following entries:

           unsigned long   d_fileno;
           unsigned short  d_reclen;
           unsigned short  d_namlen;
           char            d_name[MAXNAMELEN + 1]; /* see below */

     The d_fileno entry is a number which is unique for each distinct file in
     the filesystem.  Files that are linked by hard links (see link(2))  have
     the same d_fileno. The d_reclen entry is the length, in bytes, of the di-
     rectory record.  The d_name entry contains a null-terminated file name.
     The d_namlen entry specifies the length of the file name excluding the
     null byte.  Thus the actual size of d_name may vary from 1 to MAXNAMELEN
     + 1.

     Entries may be separated by extra space.  The d_reclen entry may be used
     as an offset from the start of a dirent structure to the next structure,
     if any.

     The actual number of bytes transferred is returned.  The current position
     pointer associated with fd is set to point to the next block of entries.
     The pointer may not advance by the number of bytes returned by
     getdirentries().  A value of zero is returned when the end of the direc-
     tory has been reached.

     getdirentries() writes the position of the block read into the location
     pointed to by basep. Alternatively, the current position pointer may be
     set and retrieved by lseek(2).  The current position pointer should only
     be set to a value returned by lseek(2),  a value returned in the location
     pointed to by basep, or zero.

RETURN VALUES
     If successful, the number of bytes actually transferred is returned.
     Otherwise, -1 is returned and the global variable errno is set to indi-
     cate the error.

ERRORS
     getdirentries() will fail if:

     [EBADF]       fd is not a valid file descriptor open for reading.

     [EFAULT]      Either buf or basep point outside the allocated address
                   space.

     [EINVAL]      The file referenced by fd is not a directory, or nbytes is
                   too small for returning a directory entry or block of en-
                   tries, or the current position pointer is invalid.

     [EIO]         An I/O error occurred while reading from or writing to the
                   file system.

SEE ALSO
     lseek(2),  open(2)

HISTORY
     The getdirentries() function first appeared in 4.4BSD.

OpenBSD 2.6                      June 9, 1993                                2