8d016e3df8
My changes to preserve errno across free() and close() and to report fstat() errors properly were blown away. Updated the FreeBSD changes to match the Lite2 style fixes.
275 lines
6.4 KiB
C
275 lines
6.4 KiB
C
/*
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* Copyright (c) 1983, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#if defined(LIBC_SCCS) && !defined(lint)
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static char sccsid[] = "@(#)opendir.c 8.8 (Berkeley) 5/1/95";
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#endif /* LIBC_SCCS and not lint */
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#include <sys/param.h>
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#include <sys/mount.h>
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#include <sys/stat.h>
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#include <dirent.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <stdlib.h>
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#include <unistd.h>
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/*
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* Open a directory.
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*/
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DIR *
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opendir(name)
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const char *name;
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{
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return (__opendir2(name, DTF_HIDEW|DTF_NODUP));
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}
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DIR *
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__opendir2(name, flags)
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const char *name;
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int flags;
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{
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DIR *dirp;
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int fd;
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int incr;
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int saved_errno;
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int unionstack;
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struct stat statb;
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/*
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* stat() before open() because opening of special files may be
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* harmful. fstat() after open because the file may have changed.
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*/
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if (stat(name, &statb) != 0)
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return (NULL);
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if (!S_ISDIR(statb.st_mode)) {
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errno = ENOTDIR;
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return (NULL);
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}
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if ((fd = open(name, O_RDONLY | O_NONBLOCK)) == -1)
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return (NULL);
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dirp = NULL;
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if (fstat(fd, &statb) != 0)
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goto fail;
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if (!S_ISDIR(statb.st_mode)) {
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errno = ENOTDIR;
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goto fail;
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}
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if (fcntl(fd, F_SETFD, FD_CLOEXEC) == -1 ||
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(dirp = malloc(sizeof(DIR))) == NULL)
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goto fail;
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/*
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* Use the system page size if that is a multiple of DIRBLKSIZ.
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* Hopefully this can be a big win someday by allowing page
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* trades to user space to be done by getdirentries().
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*/
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incr = getpagesize();
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if ((incr % DIRBLKSIZ) != 0)
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incr = DIRBLKSIZ;
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/*
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* Determine whether this directory is the top of a union stack.
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*/
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if (flags & DTF_NODUP) {
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struct statfs sfb;
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if (fstatfs(fd, &sfb) < 0)
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goto fail;
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unionstack = !strcmp(sfb.f_fstypename, "union");
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} else {
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unionstack = 0;
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}
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if (unionstack) {
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int len = 0;
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int space = 0;
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char *buf = 0;
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char *ddptr = 0;
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char *ddeptr;
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int n;
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struct dirent **dpv;
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/*
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* The strategy here is to read all the directory
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* entries into a buffer, sort the buffer, and
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* remove duplicate entries by setting the inode
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* number to zero.
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*/
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do {
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/*
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* Always make at least DIRBLKSIZ bytes
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* available to getdirentries
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*/
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if (space < DIRBLKSIZ) {
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space += incr;
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len += incr;
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buf = realloc(buf, len);
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if (buf == NULL)
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goto fail;
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ddptr = buf + (len - space);
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}
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n = getdirentries(fd, ddptr, space, &dirp->dd_seek);
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if (n > 0) {
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ddptr += n;
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space -= n;
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}
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} while (n > 0);
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ddeptr = ddptr;
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flags |= __DTF_READALL;
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/*
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* Re-open the directory.
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* This has the effect of rewinding back to the
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* top of the union stack and is needed by
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* programs which plan to fchdir to a descriptor
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* which has also been read -- see fts.c.
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*/
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if (flags & DTF_REWIND) {
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(void) close(fd);
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if ((fd = open(name, O_RDONLY)) == -1) {
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saved_errno = errno;
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free(buf);
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free(dirp);
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errno = saved_errno;
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return (NULL);
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}
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}
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/*
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* There is now a buffer full of (possibly) duplicate
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* names.
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*/
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dirp->dd_buf = buf;
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/*
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* Go round this loop twice...
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*
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* Scan through the buffer, counting entries.
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* On the second pass, save pointers to each one.
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* Then sort the pointers and remove duplicate names.
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*/
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for (dpv = 0;;) {
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n = 0;
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ddptr = buf;
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while (ddptr < ddeptr) {
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struct dirent *dp;
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dp = (struct dirent *) ddptr;
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if ((int)dp & 03)
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break;
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if ((dp->d_reclen <= 0) ||
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(dp->d_reclen > (ddeptr + 1 - ddptr)))
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break;
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ddptr += dp->d_reclen;
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if (dp->d_fileno) {
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if (dpv)
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dpv[n] = dp;
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n++;
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}
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}
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if (dpv) {
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struct dirent *xp;
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/*
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* This sort must be stable.
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*/
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mergesort(dpv, n, sizeof(*dpv), alphasort);
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dpv[n] = NULL;
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xp = NULL;
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/*
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* Scan through the buffer in sort order,
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* zapping the inode number of any
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* duplicate names.
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*/
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for (n = 0; dpv[n]; n++) {
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struct dirent *dp = dpv[n];
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if ((xp == NULL) ||
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strcmp(dp->d_name, xp->d_name)) {
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xp = dp;
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} else {
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dp->d_fileno = 0;
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}
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if (dp->d_type == DT_WHT &&
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(flags & DTF_HIDEW))
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dp->d_fileno = 0;
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}
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free(dpv);
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break;
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} else {
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dpv = malloc((n+1) * sizeof(struct dirent *));
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if (dpv == NULL)
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break;
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}
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}
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dirp->dd_len = len;
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dirp->dd_size = ddptr - dirp->dd_buf;
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} else {
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dirp->dd_len = incr;
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dirp->dd_buf = malloc(dirp->dd_len);
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if (dirp->dd_buf == NULL)
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goto fail;
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dirp->dd_seek = 0;
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flags &= ~DTF_REWIND;
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}
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dirp->dd_loc = 0;
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dirp->dd_fd = fd;
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dirp->dd_flags = flags;
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/*
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* Set up seek point for rewinddir.
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*/
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dirp->dd_rewind = telldir(dirp);
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return (dirp);
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fail:
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saved_errno = errno;
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free(dirp);
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(void) close(fd);
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errno = saved_errno;
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return (NULL);
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}
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