Imported Upstream version 93u+upstream

1 files changed, 168 insertions, 0 deletions

diff --git a/src/lib/libast/path/pathfind.c b/src/lib/libast/path/pathfind.c
new file mode 100644
index 0000000..54dc140
--- /dev/null
+++ b/src/lib/libast/path/pathfind.c
@@ -0,0 +1,168 @@
+/***********************************************************************
+*                                                                      *
+*               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
+/*
+ * Glenn Fowler
+ * AT&T Research
+ *
+ * include style search support
+ */
+
+#include <ast.h>
+#include <error.h>
+#include <ls.h>
+
+#define directory(p,s)	(stat((p),(s))>=0&&S_ISDIR((s)->st_mode))
+#define regular(p,s)	(stat((p),(s))>=0&&(S_ISREG((s)->st_mode)||streq(p,"/dev/null")))
+
+typedef struct Dir_s			/* directory list element	*/
+{
+	struct Dir_s*	next;		/* next in list			*/
+	char		dir[1];		/* directory path		*/
+} Dir_t;
+
+static struct				/* directory list state		*/
+{
+	Dir_t*		head;		/* directory list head		*/
+	Dir_t*		tail;		/* directory list tail		*/
+} state;
+
+/*
+ * append dir to pathfind() include list
+ */
+
+int
+pathinclude(const char* dir)
+{
+	register Dir_t*	dp;
+	struct stat	st;
+
+	if (dir && *dir && !streq(dir, ".") && directory(dir, &st))
+	{
+		for (dp = state.head; dp; dp = dp->next)
+			if (streq(dir, dp->dir))
+				return 0;
+		if (!(dp = oldof(0, Dir_t, 1, strlen(dir))))
+			return -1;
+		strcpy(dp->dir, dir);
+		dp->next = 0;
+		if (state.tail)
+			state.tail = state.tail->next = dp;
+		else
+			state.head = state.tail = dp;
+	}
+	return 0;
+}
+
+/*
+ * return path to name using pathinclude() list
+ * path placed in <buf,size>
+ * if lib!=0 then pathpath() attempted after include search
+ * if type!=0 and name has no '.' then file.type also attempted
+ * any *: prefix in lib is ignored (discipline library dictionary support)
+ */
+
+char*
+pathfind(const char* name, const char* lib, const char* type, char* buf, size_t size)
+{
+	register Dir_t*		dp;
+	register char*		s;
+	char			tmp[PATH_MAX];
+	struct stat		st;
+
+	if (((s = strrchr(name, '/')) || (s = (char*)name)) && strchr(s, '.'))
+		type = 0;
+
+	/*
+	 * always check the unadorned path first
+	 * this handles . and absolute paths
+	 */
+
+	if (regular(name, &st))
+	{
+		strncopy(buf, name, size);
+		return buf;
+	}
+	if (type)
+	{
+		sfsprintf(buf, size, "%s.%s", name, type);
+		if (regular(buf, &st))
+			return buf;
+	}
+	if (*name == '/')
+		return 0;
+
+	/*
+	 * check the directory of the including file
+	 * on the assumption that error_info.file is properly stacked
+	 */
+
+	if (error_info.file && (s = strrchr(error_info.file, '/')))
+	{
+		sfsprintf(buf, size, "%-.*s%s", s - error_info.file + 1, error_info.file, name);
+		if (regular(buf, &st))
+			return buf;
+		if (type)
+		{
+			sfsprintf(buf, size, "%-.*s%s%.s", s - error_info.file + 1, error_info.file, name, type);
+			if (regular(buf, &st))
+				return buf;
+		}
+	}
+
+	/*
+	 * check the include dir list
+	 */
+
+	for (dp = state.head; dp; dp = dp->next)
+	{
+		sfsprintf(tmp, sizeof(tmp), "%s/%s", dp->dir, name);
+		if (pathpath(tmp, "", PATH_REGULAR, buf, size))
+			return buf;
+		if (type)
+		{
+			sfsprintf(tmp, sizeof(tmp), "%s/%s.%s", dp->dir, name, type);
+			if (pathpath(tmp, "", PATH_REGULAR, buf, size))
+				return buf;
+		}
+	}
+
+	/*
+	 * finally a lib related search on PATH
+	 */
+
+	if (lib)
+	{
+		if (s = strrchr((char*)lib, ':'))
+			lib = (const char*)s + 1;
+		sfsprintf(tmp, sizeof(tmp), "lib/%s/%s", lib, name);
+		if (pathpath(tmp, "", PATH_REGULAR, buf, size))
+			return buf;
+		if (type)
+		{
+			sfsprintf(tmp, sizeof(tmp), "lib/%s/%s.%s", lib, name, type);
+			if (pathpath(tmp, "", PATH_REGULAR, buf, size))
+				return buf;
+		}
+	}
+	return 0;
+}