GETDIRENTRIES(2) BSD Programmer's Manual GETDIRENTRIES(2)
getdirentries - get directory entries in a filesystem independent format
getdirentries(int fd, char *buf, int nbytes, long *basep);
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 char d_type;
unsigned char 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_type entry is the type of the file pointed to by
the directory record. The file type values are defined in
<sys/dirent.h>. 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
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,
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.
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.
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.
EIO An I/O error occurred while reading from or writing to the file
The getdirentries function first appeared in 4.4BSD.
4.4BSD May 3, 1995 2