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GETDIRENTRIES(2) | System Calls Manual | GETDIRENTRIES(2) |
NAME¶
getdirentries
,
getdents
—
get directory entries in a file system independent
format
LIBRARY¶
Standard C Library (libc, -lc)SYNOPSIS¶
#include
<sys/types.h>
#include
<dirent.h>
int
getdirentries
(int
fd, char
*buf, int
nbytes, long
*basep);
int
getdents
(int
fd, char
*buf, int
nbytes);
DESCRIPTION¶
Thegetdirentries
() and
getdents
() system calls read directory
entries from the directory referenced by the file descriptor
fd into the buffer pointed to by
buf, in a file system independent format. Up
to nbytes of data will be transferred. The
nbytes argument must be greater than or equal
to the block size associated with the file, see
stat(2). Some file systems may not support these
system calls with buffers smaller than this size.
The data in the buffer is a series of dirent
structures each containing the following entries:
uint32_t d_fileno; uint16_t d_reclen; uint8_t d_type; uint8_t d_namlen; char d_name[MAXNAMELEN + 1]; /* see below */
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
() or
getdents
(). A value of zero is returned
when the end of the directory has been reached.
The getdirentries
() system call 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
(getdirentries
() only) 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 indicate the error.ERRORS¶
Thegetdirentries
() system call will fail if:
- [
EBADF
] - The fd argument 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 entries, 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¶
Thegetdirentries
() system call first
appeared in 4.4BSD. The
getdents
() system call first appeared in
FreeBSD 3.0.May 3, 1995 | Debian |