GETDIRENTRIES(3) BSD Library Functions Manual GETDIRENTRIES(3)NAMEgetdirentries — get directory entries in a filesystem independent format
SYNOPSIS
#include <dirent.h>
int
getdirentries(int fd, char *buf, int nbytes, long *basep);
DESCRIPTION
This interface is provided for compatibility only and has been obsoleted
by getdents(2).
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 buf‐
fers 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. If d_fileno is zero, the entry refers to a deleted
file.
The d_reclen entry is the length, in bytes, of the directory record.
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.
The d_name entry contains a null terminated file name.
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.
ERRORSgetdirentries() 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 system.
SEE ALSOlseek(2), open(2)HISTORY
The getdirentries() function first appeared in 4.4BSD.
BSD June 9, 1993 BSD
