Support -g option to dump value string only (no key string, no quotes).

include/lib/lib_vpd.h

 /*
  * Copyright (C) 2010 Google Inc.
  *
  * 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
@@ skipping 19 matching lines @@
 enum {
   VPD_TYPE_TERMINATOR = 0,
   VPD_TYPE_STRING,
   VPD_TYPE_IMPLICIT_TERMINATOR = 0xff,
 };
 
 enum {
   VPD_AS_LONG_AS = -1,
 };
 
-enum {
+enum {  /* export_type */
   VPD_EXPORT_KEY_VALUE = 1,
+  VPD_EXPORT_VALUE,
   VPD_EXPORT_AS_PARAMETER,
 };
 
 
 struct StringPair {
   unsigned char *key;
   unsigned char *value;
   int pad_len;
+  int filter_out;  /* TRUE means not exported. */
   struct StringPair *next;
 };
 
 struct PairContainer {
   struct StringPair *first;
 };
 
 
 /* Encodes the len into multiple bytes with the following format.
  *
@@ skipping 105 matching lines @@
 void mergeContainer(struct PairContainer *dst,
                     const struct PairContainer *src);
 
 /* Given a container, encode its all entries into the buffer.
  */
 int encodeContainer(const struct PairContainer *container,
                     const int max_buf_len,
                     unsigned char *buf,
                     int *generated);
 
+/* Set filter for exporting functions.
+ * If filter is NULL, resets the filter so that everything can be exported.
+ */
+int setContainerFilter(struct PairContainer *container,
+                       const uint8_t *filter);
+
 /*
  * Export the container content with human-readable text.
  *
  * The buf points to the first byte of buffer and *generated contains the number
  * of bytes already existed in buffer.
  *
  * Afterward, the *generated will be plused on exact bytes this function has
  * generated.
  */
 int exportContainer(const int export_type,
                     const struct PairContainer *container,
                     const int max_buf_len,
                     uint8_t *buf,
                     int *generated);
 
 void destroyContainer(struct PairContainer *container);
 
 
 #endif  /* __LIB_VPD__ */