1 files changed, 142 insertions, 0 deletions
diff --git a/src/lib/libast/path/pathcd.c b/src/lib/libast/path/pathcd.c
new file mode 100644
index 0000000..340a115
--- /dev/null
+++ b/src/lib/libast/path/pathcd.c
@@ -0,0 +1,142 @@
+/***********************************************************************
+*                                                                      *
+*               This software is part of the ast package               *
+*          Copyright (c) 1985-2011 AT&T Intellectual Property          *
+*                      and is licensed under the                       *
+*                 Eclipse Public License, Version 1.0                  *
+*                    by AT&T Intellectual Property                     *
+*                                                                      *
+*                A copy of the License is available at                 *
+*          http://www.eclipse.org/org/documents/epl-v10.html           *
+*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
+*                                                                      *
+*              Information and Software Systems Research               *
+*                            AT&T Research                             *
+*                           Florham Park NJ                            *
+*                                                                      *
+*                 Glenn Fowler <gsf@research.att.com>                  *
+*                  David Korn <dgk@research.att.com>                   *
+*                   Phong Vo <kpv@research.att.com>                    *
+*                                                                      *
+***********************************************************************/
+#pragma prototyped
+/*
+ * K. P. Vo
+ * G. S. Fowler
+ * AT&T Research
+ */
+
+#include <ast.h>
+#include <error.h>
+#include <stk.h>
+
+#if DEBUG
+
+#undef	PATH_MAX
+
+#define PATH_MAX	16
+
+static int
+vchdir(const char* path)
+{
+	int	n;
+
+	if (strlen(path) >= PATH_MAX)
+	{
+		errno = ENAMETOOLONG;
+		n = -1;
+	}
+	else n = chdir(path);
+	return n;
+}
+
+#define chdir(p)	vchdir(p)
+
+#endif
+
+/*
+ * set the current directory to path
+ * if path is long and home!=0 then pathcd(home,0)
+ * is called on intermediate chdir errors
+ */
+
+int
+pathcd(const char* path, const char* home)
+{
+	register char*	p = (char*)path;
+	register char*	s;
+	register int	n;
+	int		i;
+	int		r;
+
+	r = 0;
+	for (;;)
+	{
+		/*
+		 * this should work 99% of the time
+		 */
+
+		if (!chdir(p))
+			return r;
+
+		/*
+		 * chdir failed
+		 */
+
+		if ((n = strlen(p)) < PATH_MAX)
+			return -1;
+#ifdef ENAMETOOLONG
+		if (errno != ENAMETOOLONG)
+			return -1;
+#endif
+
+		/*
+		 * path is too long -- copy so it can be modified in place
+		 */
+
+		i = stktell(stkstd);
+		sfputr(stkstd, p, 0);
+		stkseek(stkstd, i);
+		p = stkptr(stkstd, i);
+		for (;;)
+		{
+			/*
+			 * get a short prefix component
+			 */
+
+			s = p + PATH_MAX;
+			while (--s >= p && *s != '/');
+			if (s <= p)
+				break;
+
+			/*
+			 * chdir to the prefix
+			 */
+
+			*s++ = 0;
+			if (chdir(p))
+				break;
+
+			/*
+			 * do the remainder
+			 */
+
+			if ((n -= s - p) < PATH_MAX)
+			{
+				if (chdir(s))
+					break;
+				return r;
+			}
+			p = s;
+		}
+
+		/*
+		 * try to recover back to home
+		 */
+
+		if (!(p = (char*)home))
+			return -1;
+		home = 0;
+		r = -1;
+	}
+}