mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-25 11:37:56 +00:00
205 lines
4.9 KiB
Groff
205 lines
4.9 KiB
Groff
.\" 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.
|
|
.\" 3. All advertising materials mentioning features or use of this software
|
|
.\" must display the following acknowledgement:
|
|
.\" This product includes software developed by the University of
|
|
.\" California, Berkeley and its contributors.
|
|
.\" 4. Neither the name of the University nor the names of its contributors
|
|
.\" 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
|
|
.\" $FreeBSD$
|
|
.\"
|
|
.Dd June 4, 1993
|
|
.Dt DIRECTORY 3
|
|
.Os
|
|
.Sh NAME
|
|
.Nm opendir ,
|
|
.Nm readdir ,
|
|
.Nm readdir_r ,
|
|
.Nm telldir ,
|
|
.Nm seekdir ,
|
|
.Nm rewinddir ,
|
|
.Nm closedir ,
|
|
.Nm dirfd
|
|
.Nd directory operations
|
|
.Sh LIBRARY
|
|
.Lb libc
|
|
.Sh SYNOPSIS
|
|
.In sys/types.h
|
|
.In dirent.h
|
|
.Ft DIR *
|
|
.Fn opendir "const char *filename"
|
|
.Ft struct dirent *
|
|
.Fn readdir "DIR *dirp"
|
|
.Ft int
|
|
.Fn readdir_r "DIR *dirp" "struct dirent *entry" "struct dirent **result"
|
|
.Ft long
|
|
.Fn telldir "DIR *dirp"
|
|
.Ft void
|
|
.Fn seekdir "DIR *dirp" "long loc"
|
|
.Ft void
|
|
.Fn rewinddir "DIR *dirp"
|
|
.Ft int
|
|
.Fn closedir "DIR *dirp"
|
|
.Ft int
|
|
.Fn dirfd "DIR *dirp"
|
|
.Sh DESCRIPTION
|
|
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
|
|
in subsequent operations. The pointer
|
|
.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
|
|
.Fn readdir
|
|
function
|
|
returns a pointer to the next directory entry. It returns
|
|
.Dv NULL
|
|
upon reaching the end of the directory or detecting an invalid
|
|
.Fn seekdir
|
|
operation.
|
|
.Pp
|
|
The
|
|
.Fn readdir_r
|
|
function
|
|
provides the same functionality as
|
|
.Fn readdir ,
|
|
but the caller must provide a directory
|
|
.Fa entry
|
|
buffer to store the results in. If the read succeeds,
|
|
.Fa result
|
|
is pointed at the
|
|
.Fa entry ;
|
|
upon reaching the end of the directory
|
|
.Fa result
|
|
is set to
|
|
.Dv NULL .
|
|
The
|
|
.Fn readdir_r
|
|
function
|
|
returns 0 on success or an error number to indicate failure.
|
|
.Pp
|
|
The
|
|
.Fn telldir
|
|
function
|
|
returns the current location associated with the named
|
|
.Em directory stream .
|
|
Values returned by
|
|
.Fn telldir
|
|
are good only for the lifetime of the
|
|
.Dv DIR
|
|
pointer,
|
|
.Fa dirp ,
|
|
from which they are derived. If the directory is closed and then
|
|
reopened, prior values returned by
|
|
.Fn telldir
|
|
will no longer be valid.
|
|
.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
|
|
operation was performed.
|
|
.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
|
|
.Fn dirfd
|
|
function
|
|
returns the integer file descriptor associated with the named
|
|
.Em directory stream ,
|
|
see
|
|
.Xr open 2 .
|
|
.Pp
|
|
Sample code which searches a directory for entry ``name'' is:
|
|
.Bd -literal -offset indent
|
|
len = strlen(name);
|
|
dirp = opendir(".");
|
|
while ((dp = readdir(dirp)) != NULL)
|
|
if (dp->d_namlen == len && !strcmp(dp->d_name, name)) {
|
|
(void)closedir(dirp);
|
|
return FOUND;
|
|
}
|
|
(void)closedir(dirp);
|
|
return NOT_FOUND;
|
|
.Ed
|
|
.Sh SEE ALSO
|
|
.Xr close 2 ,
|
|
.Xr lseek 2 ,
|
|
.Xr open 2 ,
|
|
.Xr read 2 ,
|
|
.Xr dir 5
|
|
.Sh HISTORY
|
|
The
|
|
.Fn opendir ,
|
|
.Fn readdir ,
|
|
.Fn telldir ,
|
|
.Fn seekdir ,
|
|
.Fn rewinddir ,
|
|
.Fn closedir ,
|
|
and
|
|
.Fn dirfd
|
|
functions appeared in
|
|
.Bx 4.2 .
|