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-rw-r--r--lib/libc/gen/getcwd.c257
1 files changed, 257 insertions, 0 deletions
diff --git a/lib/libc/gen/getcwd.c b/lib/libc/gen/getcwd.c
new file mode 100644
index 0000000..0cd3208
--- /dev/null
+++ b/lib/libc/gen/getcwd.c
@@ -0,0 +1,257 @@
+/*
+ * Copyright (c) 1989, 1991, 1993, 1995
+ * 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.
+ * 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[] = "@(#)getcwd.c 8.5 (Berkeley) 2/7/95";
+#endif /* LIBC_SCCS and not lint */
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include "namespace.h"
+#include <sys/param.h>
+#include <sys/stat.h>
+
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include "un-namespace.h"
+
+#define ISDOT(dp) \
+ (dp->d_name[0] == '.' && (dp->d_name[1] == '\0' || \
+ (dp->d_name[1] == '.' && dp->d_name[2] == '\0')))
+
+extern int __getcwd(char *, size_t);
+
+char *
+getcwd(pt, size)
+ char *pt;
+ size_t size;
+{
+ struct dirent *dp;
+ DIR *dir = NULL;
+ dev_t dev;
+ ino_t ino;
+ int first;
+ char *bpt, *bup;
+ struct stat s;
+ dev_t root_dev;
+ ino_t root_ino;
+ size_t ptsize, upsize;
+ int save_errno;
+ char *ept, *eup, *up, c;
+
+ /*
+ * If no buffer specified by the user, allocate one as necessary.
+ * If a buffer is specified, the size has to be non-zero. The path
+ * is built from the end of the buffer backwards.
+ */
+ if (pt) {
+ ptsize = 0;
+ if (!size) {
+ errno = EINVAL;
+ return (NULL);
+ }
+ if (size == 1) {
+ errno = ERANGE;
+ return (NULL);
+ }
+ ept = pt + size;
+ } else {
+ if ((pt = malloc(ptsize = PATH_MAX)) == NULL)
+ return (NULL);
+ ept = pt + ptsize;
+ }
+ if (__getcwd(pt, ept - pt) == 0) {
+ if (*pt != '/') {
+ bpt = pt;
+ ept = pt + strlen(pt) - 1;
+ while (bpt < ept) {
+ c = *bpt;
+ *bpt++ = *ept;
+ *ept-- = c;
+ }
+ }
+ return (pt);
+ }
+ bpt = ept - 1;
+ *bpt = '\0';
+
+ /*
+ * Allocate 1024 bytes for the string of "../"'s.
+ * Should always be enough. If it's not, allocate
+ * as necessary. Special case the first stat, it's ".", not "..".
+ */
+ if ((up = malloc(upsize = 1024)) == NULL)
+ goto err;
+ eup = up + upsize;
+ bup = up;
+ up[0] = '.';
+ up[1] = '\0';
+
+ /* Save root values, so know when to stop. */
+ if (stat("/", &s))
+ goto err;
+ root_dev = s.st_dev;
+ root_ino = s.st_ino;
+
+ errno = 0; /* XXX readdir has no error return. */
+
+ for (first = 1;; first = 0) {
+ /* Stat the current level. */
+ if (lstat(up, &s))
+ goto err;
+
+ /* Save current node values. */
+ ino = s.st_ino;
+ dev = s.st_dev;
+
+ /* Check for reaching root. */
+ if (root_dev == dev && root_ino == ino) {
+ *--bpt = '/';
+ /*
+ * It's unclear that it's a requirement to copy the
+ * path to the beginning of the buffer, but it's always
+ * been that way and stuff would probably break.
+ */
+ bcopy(bpt, pt, ept - bpt);
+ free(up);
+ return (pt);
+ }
+
+ /*
+ * Build pointer to the parent directory, allocating memory
+ * as necessary. Max length is 3 for "../", the largest
+ * possible component name, plus a trailing NUL.
+ */
+ while (bup + 3 + MAXNAMLEN + 1 >= eup) {
+ if ((up = reallocf(up, upsize *= 2)) == NULL)
+ goto err;
+ bup = up;
+ eup = up + upsize;
+ }
+ *bup++ = '.';
+ *bup++ = '.';
+ *bup = '\0';
+
+ /* Open and stat parent directory. */
+ if (!(dir = opendir(up)) || _fstat(dirfd(dir), &s))
+ goto err;
+
+ /* Add trailing slash for next directory. */
+ *bup++ = '/';
+ *bup = '\0';
+
+ /*
+ * If it's a mount point, have to stat each element because
+ * the inode number in the directory is for the entry in the
+ * parent directory, not the inode number of the mounted file.
+ */
+ save_errno = 0;
+ if (s.st_dev == dev) {
+ for (;;) {
+ if (!(dp = readdir(dir)))
+ goto notfound;
+ if (dp->d_fileno == ino)
+ break;
+ }
+ } else
+ for (;;) {
+ if (!(dp = readdir(dir)))
+ goto notfound;
+ if (ISDOT(dp))
+ continue;
+ bcopy(dp->d_name, bup, dp->d_namlen + 1);
+
+ /* Save the first error for later. */
+ if (lstat(up, &s)) {
+ if (!save_errno)
+ save_errno = errno;
+ errno = 0;
+ continue;
+ }
+ if (s.st_dev == dev && s.st_ino == ino)
+ break;
+ }
+
+ /*
+ * Check for length of the current name, preceding slash,
+ * leading slash.
+ */
+ while (bpt - pt < dp->d_namlen + (first ? 1 : 2)) {
+ size_t len, off;
+
+ if (!ptsize) {
+ errno = ERANGE;
+ goto err;
+ }
+ off = bpt - pt;
+ len = ept - bpt;
+ if ((pt = reallocf(pt, ptsize *= 2)) == NULL)
+ goto err;
+ bpt = pt + off;
+ ept = pt + ptsize;
+ bcopy(bpt, ept - len, len);
+ bpt = ept - len;
+ }
+ if (!first)
+ *--bpt = '/';
+ bpt -= dp->d_namlen;
+ bcopy(dp->d_name, bpt, dp->d_namlen);
+ (void) closedir(dir);
+ dir = NULL;
+
+ /* Truncate any file name. */
+ *bup = '\0';
+ }
+
+notfound:
+ /*
+ * If readdir set errno, use it, not any saved error; otherwise,
+ * didn't find the current directory in its parent directory, set
+ * errno to ENOENT.
+ */
+ if (!errno)
+ errno = save_errno ? save_errno : ENOENT;
+ /* FALLTHROUGH */
+err:
+ save_errno = errno;
+
+ if (ptsize)
+ free(pt);
+ if (dir)
+ (void) closedir(dir);
+ free(up);
+
+ errno = save_errno;
+ return (NULL);
+}
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