1 files changed, 78 insertions, 0 deletions

diff --git a/libbb/simplify_path.c b/libbb/simplify_path.c
new file mode 100644
index 000000000..4641bae88
--- /dev/null
+++ b/libbb/simplify_path.c
@@ -0,0 +1,78 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * simplify_path implementation for busybox
+ *
+ *
+ * Copyright (C) 2001  Vladimir N. Oleynik <dzo@simtreas.ru>
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <stdlib.h>
+
+#include "libbb.h"
+
+static inline char *strcpy_overlap(char *dst, const char *src)
+{
+        char *ptr = dst;
+
+        do *dst++ = *src; while (*src++);
+        return ptr;
+}
+
+char *simplify_path(const char *path)
+{
+        char *s, *start, *next;
+
+        if (path[0] == '/')
+               start = xstrdup(path);
+        else {
+               s = xgetcwd(NULL);
+               start = concat_path_file(s, path);
+               free(s);
+        }
+        s = start;
+        /* remove . and .. */
+        while(*s) {
+                if(*s++ == '/' && (*s == '/' || *s == 0)) {
+                        /* remove duplicate and trailing slashes */
+                        s = strcpy_overlap(s-1, s);
+                }
+                else if(*(s-1) == '.' && *(s-2)=='/') {
+                        if(*s == '/' || *s == 0) {
+                                /* remove . */
+                                s = strcpy_overlap(s-1, s); /* maybe set // */
+                                s--;
+                        } else if(*s == '.') {
+                                next = s+1;     /* set after ".." */
+                                if(*next == '/' || *next == 0) {  /* "../" */
+                                        if((s-=2) > start)
+                                                /* skip previous dir */
+                                                do s--; while(*s != '/');
+                                        /* remove previous dir */
+                                        strcpy_overlap(s, next);
+                                }
+
+                        }
+                }
+        }
+        if(start[0]==0) {
+                start[0]='/';
+                start[1]=0;
+        }
+        return start;
+}