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-rw-r--r--lib/libpathconv/rel2abs.c132
1 files changed, 132 insertions, 0 deletions
diff --git a/lib/libpathconv/rel2abs.c b/lib/libpathconv/rel2abs.c
new file mode 100644
index 000000000000..ac1e898ca22e
--- /dev/null
+++ b/lib/libpathconv/rel2abs.c
@@ -0,0 +1,132 @@
+/*
+ * Copyright (c) 1997 Shigio Yamaguchi. All rights reserved.
+ * Copyright (c) 1999 Tama Communications Corporation. 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
+ *
+ * $FreeBSD$
+ */
+#include <errno.h>
+#include <stdlib.h>
+#include <string.h>
+#include "pathconv.h" /* prototypes */
+/*
+ * rel2abs: convert an relative path name into absolute.
+ *
+ * i) path relative path
+ * i) base base directory (must be absolute path)
+ * o) result result buffer
+ * i) size size of result buffer
+ * r) != NULL: absolute path
+ * == NULL: error
+ */
+char *
+rel2abs(const char *path, const char *base, char *result, const size_t size)
+{
+ const char *pp, *bp;
+ /*
+ * endp points the last position which is safe in the result buffer.
+ */
+ const char *endp = result + size - 1;
+ char *rp;
+ size_t length;
+
+ if (*path == '/') {
+ if (strlen(path) >= size)
+ goto erange;
+ strcpy(result, path);
+ goto finish;
+ } else if (*base != '/' || !size) {
+ errno = EINVAL;
+ return (NULL);
+ } else if (size == 1)
+ goto erange;
+
+ length = strlen(base);
+
+ if (!strcmp(path, ".") || !strcmp(path, "./")) {
+ if (length >= size)
+ goto erange;
+ strcpy(result, base);
+ /*
+ * rp points the last char.
+ */
+ rp = result + length - 1;
+ /*
+ * remove the last '/'.
+ */
+ if (*rp == '/') {
+ if (length > 1)
+ *rp = 0;
+ } else
+ rp++;
+ /* rp point NULL char */
+ if (*++path == '/') {
+ /*
+ * Append '/' to the tail of path name.
+ */
+ *rp++ = '/';
+ if (rp > endp)
+ goto erange;
+ *rp = 0;
+ }
+ goto finish;
+ }
+ bp = base + length;
+ if (*(bp - 1) == '/')
+ --bp;
+ /*
+ * up to root.
+ */
+ for (pp = path; *pp && *pp == '.'; ) {
+ if (!strncmp(pp, "../", 3)) {
+ pp += 3;
+ while (bp > base && *--bp != '/')
+ ;
+ } else if (!strncmp(pp, "./", 2)) {
+ pp += 2;
+ } else if (!strncmp(pp, "..\0", 3)) {
+ pp += 2;
+ while (bp > base && *--bp != '/')
+ ;
+ } else
+ break;
+ }
+ /*
+ * down to leaf.
+ */
+ length = bp - base;
+ if (length >= size)
+ goto erange;
+ strncpy(result, base, length);
+ rp = result + length;
+ if (*pp || *(pp - 1) == '/' || length == 0)
+ *rp++ = '/';
+ if (rp + strlen(pp) > endp)
+ goto erange;
+ strcpy(rp, pp);
+finish:
+ return result;
+erange:
+ errno = ERANGE;
+ return (NULL);
+}