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

vpd.c

 /*
  * 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 530 matching lines @@
   printf("Usage: %s [OPTION] ...\n", progname);
   printf("   OPTIONs include:\n");
   printf("      -h               This help page and version.\n");
   printf("      -f <filename>    The output file name.\n");
   printf("      -E <address>     EPS base address (default:0x240000).\n");
   printf("      -s <key=value>   To add/change a string value.\n");
   printf("      -p <pad length>  Pad if length is shorter.\n");
   printf("      -i <partition>   Specify VPD partition name in fmap.\n");
   printf("      -l               List content in the file.\n");
   printf("      -O               Overwrite and re-format VPD partition.\n");
+  printf("      -g <key>         Print value string only.\n");
   printf("\n");
 }
 
 int main(int argc, char *argv[]) {
   int opt;
   int option_index = 0;
   int retval = 0;
-  const char *optstring = "hf:E:s:p:i:lO";
+  const char *optstring = "hf:E:s:p:i:lOg:";
   static struct option long_options[] = {
     {"help", 0, 0, 'h'},
     {"file", 0, 0, 'f'},
     {"epsbase", 0, 0, 'E'},
     {"string", 0, 0, 's'},
     {"pad", 0, 0, 'p'},
     {"partition", 0, 0, 'i'},
     {"list", 0, 0, 'l'},
     {"overwrite", 0, 0, 'O'},
+    {"filter", 0, 0, 'g'},
     {0, 0, 0, 0}
   };
   char *filename = NULL;
+  char *filter_str = NULL;
   int write_back_to_flash = 0;
   int list_it = 0;
   int overwrite_it = 0;
   int modified = 0;
   int fd;
 
   initContainer(&file);
   initContainer(&argument);
 
   while ((opt = getopt_long(argc, argv, optstring,
@@ skipping 52 matching lines @@
       case 'l':
         list_it = 1;
         break;
 
       case 'O':
         overwrite_it = 1;
         modified = 1;  /* This option forces to write empty data back even
                         * no new pair is given. */
         break;
 
+      case 'g':
+        filter_str = strdup(optarg);
+        break;
+
       default:
-        fprintf(stderr, "Invalid option, use --help for usage.\n");
+        fprintf(stderr, "Invalid option (%s), use --help for usage.\n", optarg);
         retval = 1;
         goto teardown;
         break;
     }
   }
 
   if (optind < argc) {
     fprintf(stderr, "[ERROR] unexpected argument: %s\n\n", argv[optind]);
     usage(argv[0]);
     retval = 1;
     goto teardown;
   }
 
   if (generateTempFilenames() < 0) {
+    fprintf(stderr, "[ERROR] generateTempFilenames() returns failed.\n");
     retval = 1;
     goto teardown;
   }
+
+  if (list_it && filter_str) {
+    fprintf(stderr, "[ERROR] -l and -g must be mutually exclusive.\n");
+    retval = 1;
+    goto teardown;
+  }
 
   /* to avoid malicious attack, we replace suspicious chars. */
   fmapNormalizeAreaName(fmap_vpd_area_name);
 
   /* if no filename is specified, call flashrom to read from flash. */
   if (!filename) {
     if (FLASHROM_OK != flashromRead(tmp_part_file, tmp_full_file,
                                     fmap_vpd_area_name)) {
       fprintf(stderr, "flashromRead() error!\n");
       retval = 1;
       goto teardown;
     }
     write_back_to_flash = 1;
     filename = strdup(tmp_part_file);
   }
 
   if (retval = loadFile(filename, &file, overwrite_it)) {
     fprintf(stderr, "loadFile('%s') error.\n", filename);
     goto teardown;
   }
 
   mergeContainer(&file, &argument);
 
-  if (list_it) {
+  if (list_it || filter_str) {
     /* Reserve larger size because the exporting generates longer string than
      * the encoded data. */
     uint8_t list_buf[BUF_LEN * 2];
     int list_len = 0;
 
-    if (VPD_OK != exportContainer(VPD_EXPORT_KEY_VALUE, &file,
-                                  sizeof(list_buf), list_buf, &list_len)) {
+    if (filter_str) setContainerFilter(&file, filter_str);
+    if (VPD_OK != exportContainer(
+          (filter_str) ? VPD_EXPORT_VALUE : VPD_EXPORT_KEY_VALUE,
+          &file, sizeof(list_buf), list_buf, &list_len)) {
       fprintf(stderr, "exportContainer(): Cannot generate string.\n");
       retval = 1;
       goto teardown;
     }
     printf("%s", list_buf);
   }
 
   if (modified) {
     if (retval = saveFile(&file, filename)) {
       fprintf(stderr, "saveFile('%s') error.\n", filename);
       goto teardown;
     }
 
     if (write_back_to_flash) {
       if (FLASHROM_OK != flashromPartialWrite(filename, tmp_full_file,
                                               fmap_vpd_area_name)) {
         fprintf(stderr, "flashromPartialWrite() error.\n");
         retval = 1;
         goto teardown;
       }
     }
   }
 
 teardown:
   if (spd_data) free(spd_data);
   if (filename) free(filename);
+  if (filter_str) free(filter_str);
   destroyContainer(&file);
   destroyContainer(&argument);
 
   return retval;
 }