2 files changed, 46 insertions, 0 deletions

diff --git a/include/libbb.h b/include/libbb.h
index f79d80d7f..0170085cb 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -260,6 +260,7 @@ DIR *warn_opendir(const char *path);
 
 /* UNUSED: char *xmalloc_realpath(const char *path); */
 char *xmalloc_readlink(const char *path);
+char *xmalloc_readlink_follow(const char *path);
 char *xmalloc_readlink_or_warn(const char *path);
 char *xrealloc_getcwd_or_warn(char *cwd);
 
diff --git a/libbb/xreadlink.c b/libbb/xreadlink.c
index 98b795f56..2f6b1e237 100644
--- a/libbb/xreadlink.c
+++ b/libbb/xreadlink.c
@@ -32,6 +32,51 @@ char *xmalloc_readlink(const char *path)
         return buf;
 }
 
+/*
+ * this routine is not the same as realpath(), which canonicalizes
+ * the given path completely.  this routine only follows trailing
+ * symlinks until a real file is reached, and returns its name. 
+ * intermediate symlinks are not expanded.  as above, a malloced
+ * char* is returned, which must be freed.
+ */
+char *xmalloc_readlink_follow(const char *path)
+{
+        char *buf = NULL, *lpc, *linkpath;
+        int bufsize;
+        smallint looping = 0;
+
+        buf = strdup(path);
+        bufsize = strlen(path) + 1;
+
+        while(1) {
+                linkpath = xmalloc_readlink(buf);
+                if (!linkpath) {
+                        if (errno == EINVAL) /* not a symlink */
+                                return buf;
+                        free(buf);
+                        return NULL;
+                } 
+
+                if (*linkpath == '/') {
+                        free(buf);
+                        buf = linkpath;
+                        bufsize = strlen(linkpath) + 1;
+                } else {
+                        bufsize += strlen(linkpath);
+                        if (looping++ > MAXSYMLINKS) {
+                                free(linkpath);
+                                free(buf);
+                                return NULL;
+                        }
+                        buf = xrealloc(buf, bufsize);
+                        lpc = bb_get_last_path_component_strip(buf);
+                        strcpy(lpc, linkpath);
+                        free(linkpath);
+                }
+        }
+
+}
+
 char *xmalloc_readlink_or_warn(const char *path)
 {
         char *buf = xmalloc_readlink(path);