Made new xreadlink function for libbb and changed applets to use it instead of

readlink(2).

1 files changed, 34 insertions, 0 deletions

diff --git a/libbb/xreadlink.c b/libbb/xreadlink.c
new file mode 100644
index 000000000..66f63b883
--- /dev/null
+++ b/libbb/xreadlink.c
@@ -0,0 +1,34 @@
+/*
+ *  xreadlink.c - safe implementation of readlink
+ */
+
+#include <stdio.h>
+
+/*
+ * NOTE: This function returns a malloced char* that you will have to free
+ * yourself. You have been warned.
+ */
+
+#include <unistd.h>
+#include "libbb.h"
+
+extern char *xreadlink(const char *path)
+{                       
+        static const int GROWBY = 80; /* how large we will grow strings by */
+
+        char *buf = NULL;   
+        int bufsize = 0, readsize = 0;
+
+        do {
+                buf = xrealloc(buf, bufsize += GROWBY);
+                readsize = readlink(path, buf, bufsize); /* 1st try */
+                if (readsize == -1)
+                        perror_msg("%s:%s", applet_name, path);
+        }           
+        while (bufsize < readsize + 1);
+
+        buf[readsize] = '\0';
+
+        return buf;
+}       
+