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-rw-r--r--newlib/libc/posix/telldir.c133
1 files changed, 133 insertions, 0 deletions
diff --git a/newlib/libc/posix/telldir.c b/newlib/libc/posix/telldir.c
new file mode 100644
index 00000000000..90b12f99cbd
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+++ b/newlib/libc/posix/telldir.c
@@ -0,0 +1,133 @@
+#ifndef HAVE_OPENDIR
+
+/*
+ * Copyright (c) 1983 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.
+ */
+
+#if defined(LIBC_SCCS) && !defined(lint)
+static char sccsid[] = "@(#)telldir.c 5.9 (Berkeley) 2/23/91";
+#endif /* LIBC_SCCS and not lint */
+
+#include <sys/param.h>
+#include <dirent.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+/*
+ * The option SINGLEUSE may be defined to say that a telldir
+ * cookie may be used only once before it is freed. This option
+ * is used to avoid having memory usage grow without bound.
+ */
+#define SINGLEUSE
+
+/*
+ * One of these structures is malloced to describe the current directory
+ * position each time telldir is called. It records the current magic
+ * cookie returned by getdirentries and the offset within the buffer
+ * associated with that return value.
+ */
+struct ddloc {
+ struct ddloc *loc_next;/* next structure in list */
+ long loc_index; /* key associated with structure */
+ long loc_seek; /* magic cookie returned by getdirentries */
+ long loc_loc; /* offset of entry in buffer */
+};
+
+#define NDIRHASH 32 /* Num of hash lists, must be a power of 2 */
+#define LOCHASH(i) ((i)&(NDIRHASH-1))
+
+static long dd_loccnt; /* Index of entry for sequential readdir's */
+static struct ddloc *dd_hash[NDIRHASH]; /* Hash list heads for ddlocs */
+
+/*
+ * return a pointer into a directory
+ */
+long
+telldir(dirp)
+ const DIR *dirp;
+{
+ register int index;
+ register struct ddloc *lp;
+
+ if ((lp = (struct ddloc *)malloc(sizeof(struct ddloc))) == NULL)
+ return (-1);
+ index = dd_loccnt++;
+ lp->loc_index = index;
+ lp->loc_seek = dirp->dd_seek;
+ lp->loc_loc = dirp->dd_loc;
+ lp->loc_next = dd_hash[LOCHASH(index)];
+ dd_hash[LOCHASH(index)] = lp;
+ return (index);
+}
+
+/*
+ * seek to an entry in a directory.
+ * Only values returned by "telldir" should be passed to seekdir.
+ */
+void
+_seekdir(dirp, loc)
+ register DIR *dirp;
+ long loc;
+{
+ register struct ddloc *lp;
+ register struct ddloc **prevlp;
+ struct dirent *dp;
+ extern long lseek();
+
+ prevlp = &dd_hash[LOCHASH(loc)];
+ lp = *prevlp;
+ while (lp != NULL) {
+ if (lp->loc_index == loc)
+ break;
+ prevlp = &lp->loc_next;
+ lp = lp->loc_next;
+ }
+ if (lp == NULL)
+ return;
+ if (lp->loc_loc == dirp->dd_loc && lp->loc_seek == dirp->dd_seek)
+ goto found;
+ (void) lseek(dirp->dd_fd, lp->loc_seek, 0);
+ dirp->dd_seek = lp->loc_seek;
+ dirp->dd_loc = 0;
+ while (dirp->dd_loc < lp->loc_loc) {
+ dp = readdir(dirp);
+ if (dp == NULL)
+ break;
+ }
+found:
+#ifdef SINGLEUSE
+ *prevlp = lp->loc_next;
+ free((caddr_t)lp);
+#endif
+}
+
+#endif /* ! HAVE_OPENDIR */