1994-05-27 05:00:24 +00:00
|
|
|
.\" Copyright (c) 1983, 1991, 1993
|
|
|
|
.\" The Regents of the University of California. All rights reserved.
|
|
|
|
.\"
|
|
|
|
.\" Redistribution and use in source and binary forms, with or without
|
|
|
|
.\" modification, are permitted provided that the following conditions
|
|
|
|
.\" are met:
|
|
|
|
.\" 1. Redistributions of source code must retain the above copyright
|
|
|
|
.\" notice, this list of conditions and the following disclaimer.
|
|
|
|
.\" 2. Redistributions in binary form must reproduce the above copyright
|
|
|
|
.\" notice, this list of conditions and the following disclaimer in the
|
|
|
|
.\" documentation and/or other materials provided with the distribution.
|
2017-02-28 23:42:47 +00:00
|
|
|
.\" 3. Neither the name of the University nor the names of its contributors
|
1994-05-27 05:00:24 +00:00
|
|
|
.\" may be used to endorse or promote products derived from this software
|
|
|
|
.\" without specific prior written permission.
|
|
|
|
.\"
|
|
|
|
.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
|
|
|
|
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
|
|
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
|
|
.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
|
|
|
|
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
|
|
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
|
|
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
|
|
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
|
|
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
|
|
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
|
|
.\" SUCH DAMAGE.
|
|
|
|
.\"
|
|
|
|
.\" @(#)directory.3 8.1 (Berkeley) 6/4/93
|
1999-08-28 00:22:10 +00:00
|
|
|
.\" $FreeBSD$
|
1994-05-27 05:00:24 +00:00
|
|
|
.\"
|
2020-08-04 08:46:28 +00:00
|
|
|
.Dd August 1, 2020
|
1994-05-27 05:00:24 +00:00
|
|
|
.Dt DIRECTORY 3
|
2001-07-10 13:41:46 +00:00
|
|
|
.Os
|
1994-05-27 05:00:24 +00:00
|
|
|
.Sh NAME
|
|
|
|
.Nm opendir ,
|
2008-04-16 18:59:36 +00:00
|
|
|
.Nm fdopendir ,
|
1994-05-27 05:00:24 +00:00
|
|
|
.Nm readdir ,
|
1999-11-29 06:12:22 +00:00
|
|
|
.Nm readdir_r ,
|
1994-05-27 05:00:24 +00:00
|
|
|
.Nm telldir ,
|
|
|
|
.Nm seekdir ,
|
|
|
|
.Nm rewinddir ,
|
|
|
|
.Nm closedir ,
|
2013-08-18 20:11:34 +00:00
|
|
|
.Nm fdclosedir ,
|
1994-05-27 05:00:24 +00:00
|
|
|
.Nm dirfd
|
|
|
|
.Nd directory operations
|
2000-04-21 09:42:15 +00:00
|
|
|
.Sh LIBRARY
|
|
|
|
.Lb libc
|
1994-05-27 05:00:24 +00:00
|
|
|
.Sh SYNOPSIS
|
2001-10-01 16:09:29 +00:00
|
|
|
.In dirent.h
|
1994-05-27 05:00:24 +00:00
|
|
|
.Ft DIR *
|
|
|
|
.Fn opendir "const char *filename"
|
2008-04-16 18:59:36 +00:00
|
|
|
.Ft DIR *
|
|
|
|
.Fn fdopendir "int fd"
|
1994-05-27 05:00:24 +00:00
|
|
|
.Ft struct dirent *
|
|
|
|
.Fn readdir "DIR *dirp"
|
1999-11-29 06:12:22 +00:00
|
|
|
.Ft int
|
|
|
|
.Fn readdir_r "DIR *dirp" "struct dirent *entry" "struct dirent **result"
|
1994-05-27 05:00:24 +00:00
|
|
|
.Ft long
|
2000-12-06 03:15:49 +00:00
|
|
|
.Fn telldir "DIR *dirp"
|
1994-05-27 05:00:24 +00:00
|
|
|
.Ft void
|
2004-07-03 22:30:10 +00:00
|
|
|
.Fn seekdir "DIR *dirp" "long loc"
|
1994-05-27 05:00:24 +00:00
|
|
|
.Ft void
|
|
|
|
.Fn rewinddir "DIR *dirp"
|
|
|
|
.Ft int
|
|
|
|
.Fn closedir "DIR *dirp"
|
|
|
|
.Ft int
|
2013-08-18 20:11:34 +00:00
|
|
|
.Fn fdclosedir "DIR *dirp"
|
|
|
|
.Ft int
|
1994-05-27 05:00:24 +00:00
|
|
|
.Fn dirfd "DIR *dirp"
|
|
|
|
.Sh DESCRIPTION
|
2016-08-31 20:38:40 +00:00
|
|
|
.Bf -symbolic
|
|
|
|
The
|
|
|
|
.Fn readdir_r
|
|
|
|
interface is deprecated
|
|
|
|
because it cannot be used correctly unless
|
|
|
|
.Brq Va NAME_MAX
|
|
|
|
is a fixed value.
|
|
|
|
.Ef
|
|
|
|
.Pp
|
1994-05-27 05:00:24 +00:00
|
|
|
The
|
|
|
|
.Fn opendir
|
|
|
|
function
|
|
|
|
opens the directory named by
|
|
|
|
.Fa filename ,
|
|
|
|
associates a
|
|
|
|
.Em directory stream
|
|
|
|
with it
|
|
|
|
and
|
|
|
|
returns a pointer to be used to identify the
|
|
|
|
.Em directory stream
|
2004-07-02 23:52:20 +00:00
|
|
|
in subsequent operations.
|
|
|
|
The pointer
|
1994-05-27 05:00:24 +00:00
|
|
|
.Dv NULL
|
|
|
|
is returned if
|
|
|
|
.Fa filename
|
|
|
|
cannot be accessed, or if it cannot
|
|
|
|
.Xr malloc 3
|
|
|
|
enough memory to hold the whole thing.
|
|
|
|
.Pp
|
|
|
|
The
|
2008-04-16 18:59:36 +00:00
|
|
|
.Fn fdopendir
|
|
|
|
function is equivalent to the
|
|
|
|
.Fn opendir
|
|
|
|
function except that the directory is specified by a file descriptor
|
|
|
|
.Fa fd
|
|
|
|
rather than by a name.
|
|
|
|
The file offset associated with the file descriptor at the time of the call
|
|
|
|
determines which entries are returned.
|
|
|
|
.Pp
|
|
|
|
Upon successful return from
|
|
|
|
.Fn fdopendir ,
|
|
|
|
the file descriptor is under the control of the system,
|
|
|
|
and if any attempt is made to close the file descriptor,
|
|
|
|
or to modify the state of the associated description other than by means
|
|
|
|
of
|
|
|
|
.Fn closedir ,
|
|
|
|
.Fn readdir ,
|
|
|
|
.Fn readdir_r ,
|
|
|
|
or
|
|
|
|
.Fn rewinddir ,
|
|
|
|
the behavior is undefined.
|
|
|
|
Upon calling
|
|
|
|
.Fn closedir
|
|
|
|
the file descriptor is closed.
|
|
|
|
The
|
|
|
|
.Dv FD_CLOEXEC
|
|
|
|
flag is set on the file descriptor by a successful call to
|
|
|
|
.Fn fdopendir .
|
|
|
|
.Pp
|
|
|
|
The
|
1994-05-27 05:00:24 +00:00
|
|
|
.Fn readdir
|
|
|
|
function
|
2004-07-02 23:52:20 +00:00
|
|
|
returns a pointer to the next directory entry.
|
2016-08-31 20:38:40 +00:00
|
|
|
The directory entry remains valid until the next call to
|
|
|
|
.Fn readdir
|
|
|
|
or
|
|
|
|
.Fn closedir
|
|
|
|
on the same
|
|
|
|
.Em directory stream .
|
|
|
|
The function returns
|
1994-05-27 05:00:24 +00:00
|
|
|
.Dv NULL
|
2012-02-09 20:49:03 +00:00
|
|
|
upon reaching the end of the directory or on error.
|
|
|
|
In the event of an error,
|
|
|
|
.Va errno
|
|
|
|
may be set to any of the values documented for the
|
|
|
|
.Xr getdirentries 2
|
|
|
|
system call.
|
1994-05-27 05:00:24 +00:00
|
|
|
.Pp
|
2002-12-18 10:13:54 +00:00
|
|
|
The
|
1999-11-29 06:12:22 +00:00
|
|
|
.Fn readdir_r
|
2002-12-18 10:13:54 +00:00
|
|
|
function
|
1999-11-29 06:12:22 +00:00
|
|
|
provides the same functionality as
|
|
|
|
.Fn readdir ,
|
|
|
|
but the caller must provide a directory
|
|
|
|
.Fa entry
|
2004-07-02 23:52:20 +00:00
|
|
|
buffer to store the results in.
|
2016-08-31 20:38:40 +00:00
|
|
|
The buffer must be large enough for a
|
|
|
|
.Vt struct dirent
|
|
|
|
with a
|
|
|
|
.Va d_name
|
|
|
|
array with
|
|
|
|
.Brq Va NAME_MAX
|
|
|
|
+ 1 elements.
|
2004-07-02 23:52:20 +00:00
|
|
|
If the read succeeds,
|
1999-11-29 06:12:22 +00:00
|
|
|
.Fa result
|
|
|
|
is pointed at the
|
|
|
|
.Fa entry ;
|
|
|
|
upon reaching the end of the directory
|
|
|
|
.Fa result
|
|
|
|
is set to
|
|
|
|
.Dv NULL .
|
2002-12-18 10:13:54 +00:00
|
|
|
The
|
1999-11-29 06:12:22 +00:00
|
|
|
.Fn readdir_r
|
2002-12-18 10:13:54 +00:00
|
|
|
function
|
1999-11-29 06:12:22 +00:00
|
|
|
returns 0 on success or an error number to indicate failure.
|
|
|
|
.Pp
|
1994-05-27 05:00:24 +00:00
|
|
|
The
|
|
|
|
.Fn telldir
|
|
|
|
function
|
2012-07-05 17:02:20 +00:00
|
|
|
returns a token representing the current location associated with the named
|
1994-05-27 05:00:24 +00:00
|
|
|
.Em directory stream .
|
1998-06-03 06:54:24 +00:00
|
|
|
Values returned by
|
|
|
|
.Fn telldir
|
|
|
|
are good only for the lifetime of the
|
|
|
|
.Dv DIR
|
|
|
|
pointer,
|
|
|
|
.Fa dirp ,
|
2004-07-02 23:52:20 +00:00
|
|
|
from which they are derived.
|
|
|
|
If the directory is closed and then
|
1998-06-03 06:54:24 +00:00
|
|
|
reopened, prior values returned by
|
|
|
|
.Fn telldir
|
|
|
|
will no longer be valid.
|
2014-07-29 00:16:33 +00:00
|
|
|
Values returned by
|
|
|
|
.Fn telldir
|
|
|
|
are also invalidated by a call to
|
|
|
|
.Fn rewinddir .
|
1994-05-27 05:00:24 +00:00
|
|
|
.Pp
|
|
|
|
The
|
|
|
|
.Fn seekdir
|
|
|
|
function
|
|
|
|
sets the position of the next
|
|
|
|
.Fn readdir
|
|
|
|
operation on the
|
|
|
|
.Em directory stream .
|
|
|
|
The new position reverts to the one associated with the
|
|
|
|
.Em directory stream
|
|
|
|
when the
|
|
|
|
.Fn telldir
|
2000-10-30 13:23:19 +00:00
|
|
|
operation was performed.
|
1994-05-27 05:00:24 +00:00
|
|
|
.Pp
|
|
|
|
The
|
|
|
|
.Fn rewinddir
|
|
|
|
function
|
|
|
|
resets the position of the named
|
|
|
|
.Em directory stream
|
|
|
|
to the beginning of the directory.
|
|
|
|
.Pp
|
|
|
|
The
|
|
|
|
.Fn closedir
|
|
|
|
function
|
|
|
|
closes the named
|
|
|
|
.Em directory stream
|
|
|
|
and frees the structure associated with the
|
|
|
|
.Fa dirp
|
|
|
|
pointer,
|
|
|
|
returning 0 on success.
|
|
|
|
On failure, \-1 is returned and the global variable
|
|
|
|
.Va errno
|
|
|
|
is set to indicate the error.
|
|
|
|
.Pp
|
|
|
|
The
|
2013-08-18 20:11:34 +00:00
|
|
|
.Fn fdclosedir
|
|
|
|
function is equivalent to the
|
|
|
|
.Fn closedir
|
|
|
|
function except that this function returns directory file descriptor instead of
|
|
|
|
closing it.
|
|
|
|
.Pp
|
|
|
|
The
|
1994-05-27 05:00:24 +00:00
|
|
|
.Fn dirfd
|
|
|
|
function
|
|
|
|
returns the integer file descriptor associated with the named
|
|
|
|
.Em directory stream ,
|
|
|
|
see
|
|
|
|
.Xr open 2 .
|
2020-08-04 08:46:28 +00:00
|
|
|
.Sh EXAMPLES
|
1996-01-30 16:34:52 +00:00
|
|
|
Sample code which searches a directory for entry ``name'' is:
|
1994-05-27 05:00:24 +00:00
|
|
|
.Bd -literal -offset indent
|
|
|
|
dirp = opendir(".");
|
2011-03-26 07:15:57 +00:00
|
|
|
if (dirp == NULL)
|
|
|
|
return (ERROR);
|
2011-03-26 07:17:24 +00:00
|
|
|
len = strlen(name);
|
2011-03-26 07:15:57 +00:00
|
|
|
while ((dp = readdir(dirp)) != NULL) {
|
|
|
|
if (dp->d_namlen == len && strcmp(dp->d_name, name) == 0) {
|
1994-05-27 05:00:24 +00:00
|
|
|
(void)closedir(dirp);
|
2011-03-26 07:15:57 +00:00
|
|
|
return (FOUND);
|
1994-05-27 05:00:24 +00:00
|
|
|
}
|
2011-03-26 07:15:57 +00:00
|
|
|
}
|
1994-05-27 05:00:24 +00:00
|
|
|
(void)closedir(dirp);
|
2011-03-26 07:15:57 +00:00
|
|
|
return (NOT_FOUND);
|
1994-05-27 05:00:24 +00:00
|
|
|
.Ed
|
2020-08-04 08:46:28 +00:00
|
|
|
.Sh ERRORS
|
|
|
|
The
|
|
|
|
.Fn opendir
|
|
|
|
function will fail if:
|
|
|
|
.Bl -tag -width Er
|
|
|
|
.It Bq Er EACCES
|
|
|
|
Search permission is denied for the component of the path prefix of
|
|
|
|
.Fa filename
|
|
|
|
or read permission is denied for
|
|
|
|
.Fa filename .
|
|
|
|
.It Bq Er ELOOP
|
|
|
|
A loop exists in symbolic links encountered during resolution of the
|
|
|
|
.Fa filename
|
|
|
|
argument.
|
|
|
|
.It Bq Er ENAMETOOLONG
|
|
|
|
The length of the
|
|
|
|
.Fa filename
|
|
|
|
argument exceeds
|
|
|
|
.Brq Dv PATH_MAX
|
|
|
|
or
|
|
|
|
a pathname component is longer than
|
|
|
|
.Brq Dv NAME_MAX .
|
|
|
|
.It Bq Er ENOENT
|
|
|
|
A component of
|
|
|
|
.Fa filename
|
|
|
|
does not name an existing directory or
|
|
|
|
.Fa filename
|
|
|
|
is an empty string.
|
|
|
|
.It Bq Er ENOTDIR
|
|
|
|
A component of
|
|
|
|
.Fa filename
|
|
|
|
is not a directory.
|
|
|
|
.El
|
|
|
|
.Pp
|
|
|
|
The
|
|
|
|
.Fn fdopendir
|
|
|
|
function will fail if:
|
|
|
|
.Bl -tag -width Er
|
|
|
|
.It Bq Er EBADF
|
|
|
|
The
|
|
|
|
.Fa fd
|
|
|
|
argument is not a valid file descriptor open for reading.
|
|
|
|
.It Bq Er ENOTDIR
|
|
|
|
The descriptor
|
|
|
|
.Fa fd
|
|
|
|
is not associated with a directory.
|
|
|
|
.El
|
|
|
|
.Pp
|
|
|
|
The
|
|
|
|
.Fn readdir
|
|
|
|
and
|
|
|
|
.Fn readdir_r
|
|
|
|
functions may also fail and set
|
|
|
|
.Va errno
|
|
|
|
for any of the errors specified for the routine
|
|
|
|
.Xr getdents 2 .
|
|
|
|
.Pp
|
|
|
|
The
|
|
|
|
.Fn telldir
|
|
|
|
function may also fail and set
|
|
|
|
.Va errno
|
|
|
|
for any of the errors specified for the routine
|
|
|
|
.Xr realloc 3 .
|
|
|
|
.Pp
|
|
|
|
The
|
|
|
|
.Fn closedir
|
|
|
|
function may also fail and set
|
|
|
|
.Va errno
|
|
|
|
for any of the errors specified for the routine
|
|
|
|
.Xr close 2 .
|
1994-05-27 05:00:24 +00:00
|
|
|
.Sh SEE ALSO
|
|
|
|
.Xr close 2 ,
|
|
|
|
.Xr lseek 2 ,
|
1997-01-20 23:23:22 +00:00
|
|
|
.Xr open 2 ,
|
|
|
|
.Xr read 2 ,
|
1994-05-27 05:00:24 +00:00
|
|
|
.Xr dir 5
|
2019-05-02 19:59:37 +00:00
|
|
|
.Sh STANDARDS
|
|
|
|
The
|
|
|
|
.Fn closedir ,
|
|
|
|
.Fn dirfd ,
|
|
|
|
.Fn fdopendir ,
|
|
|
|
.Fn opendir ,
|
|
|
|
.Fn readdir ,
|
|
|
|
.Fn readdir_r ,
|
|
|
|
.Fn rewinddir ,
|
|
|
|
.Fn seekdir
|
|
|
|
and
|
|
|
|
.Fn telldir
|
|
|
|
functions are expected to conform to
|
|
|
|
.St -p1003.1-2008 .
|
|
|
|
The
|
|
|
|
.Fn fdclosedir
|
|
|
|
function and the
|
|
|
|
.Fa d_off ,
|
|
|
|
.Fa d_reclen
|
|
|
|
and
|
|
|
|
.Fa d_type
|
|
|
|
fields of
|
|
|
|
.Vt struct dirent
|
|
|
|
are non-standard, and should not be used in portable programs.
|
1994-05-27 05:00:24 +00:00
|
|
|
.Sh HISTORY
|
|
|
|
The
|
|
|
|
.Fn opendir ,
|
|
|
|
.Fn readdir ,
|
|
|
|
.Fn telldir ,
|
|
|
|
.Fn seekdir ,
|
|
|
|
.Fn rewinddir ,
|
|
|
|
.Fn closedir ,
|
|
|
|
and
|
|
|
|
.Fn dirfd
|
|
|
|
functions appeared in
|
|
|
|
.Bx 4.2 .
|
2008-04-16 18:59:36 +00:00
|
|
|
The
|
|
|
|
.Fn fdopendir
|
|
|
|
function appeared in
|
|
|
|
.Fx 8.0 .
|
2013-08-18 20:11:34 +00:00
|
|
|
.Fn fdclosedir
|
|
|
|
function appeared in
|
|
|
|
.Fx 10.0 .
|
2012-07-05 17:02:20 +00:00
|
|
|
.Sh BUGS
|
2015-05-05 14:52:33 +00:00
|
|
|
The behaviour of
|
|
|
|
.Fn telldir
|
|
|
|
and
|
|
|
|
.Fn seekdir
|
|
|
|
is likely to be wrong if there are parallel unlinks happening
|
|
|
|
and the directory is larger than one page.
|
|
|
|
There is code to ensure that a
|
|
|
|
.Fn seekdir
|
2017-05-23 06:55:51 +00:00
|
|
|
to the location given by a
|
2015-05-05 14:52:33 +00:00
|
|
|
.Fn telldir
|
2017-05-23 06:55:51 +00:00
|
|
|
immediately before the last
|
2015-05-05 14:52:33 +00:00
|
|
|
.Fn readdir
|
|
|
|
will always set the correct location to return the same value as that last
|
|
|
|
.Fn readdir
|
|
|
|
performed.
|
2017-05-23 06:55:51 +00:00
|
|
|
This is enough for some applications which want to
|
2017-05-23 17:34:10 +00:00
|
|
|
"push back the last entry read", e.g., Samba.
|
2015-05-05 14:52:33 +00:00
|
|
|
Seeks back to any other location,
|
|
|
|
other than the beginning of the directory,
|
|
|
|
may result in unexpected behaviour if deletes are present.
|
|
|
|
It is hoped that this situation will be resolved with changes to
|
|
|
|
.Fn getdirentries
|
|
|
|
and the VFS.
|