/*

 * resolve.c - resolve names and tags into specific devices

 *

 * Copyright (C) 2001, 2003 Theodore Ts'o.

 * Copyright (C) 2001 Andreas Dilger

 *

 * %Begin-Header%

 * This file may be redistributed under the terms of the

 * GNU Lesser General Public License.

 * %End-Header%

 */

#include <stdio.h>

#ifdef HAVE_UNISTD_H

#include <unistd.h>

#endif

#include <stdlib.h>

#include <fcntl.h>

#include <string.h>

#include <sys/types.h>

#include <sys/stat.h>

#include "blkidP.h"

/*

 * Find a tagname (e.g. LABEL or UUID) on a specific device.

 */

char *blkid_get_tag_value(blkid_cache cache, const char *tagname,

        const char *devname)

{

  blkid_tag found;

  blkid_dev dev;

  blkid_cache c = cache;

  char *ret = NULL;

  DBG(TAG, ul_debug("looking for tag %s on %s device", tagname, devname));

  if (!devname)

    return NULL;

  if (!cache && blkid_get_cache(&c, NULL) < 0)

    return NULL;

  if ((dev = blkid_get_dev(c, devname, BLKID_DEV_NORMAL)) &&

      (found = blkid_find_tag_dev(dev, tagname)))

    ret = found->bit_val ? strdup(found->bit_val) : NULL;

  if (!cache)

    blkid_put_cache(c);

  return ret;

}

/*

 * Locate a device name from a token (NAME=value string), or (name, value)

 * pair.  In the case of a token, value is ignored.  If the "token" is not

 * of the form "NAME=value" and there is no value given, then it is assumed

 * to be the actual devname and a copy is returned.

 */

char *blkid_get_devname(blkid_cache cache, const char *token,

      const char *value)

{

  blkid_dev dev;

  blkid_cache c = cache;

  char *t = NULL, *v = NULL;

  char *ret = NULL;

  if (!token)

    return NULL;

  if (!cache && blkid_get_cache(&c, NULL) < 0)

    return NULL;

  DBG(TAG, ul_debug("looking for %s%s%s %s", token, value ? "=" : "",

       value ? value : "", cache ? "in cache" : "from disk"));

  if (!value) {

    if (!strchr(token, '=')) {

      ret = strdup(token);

      goto out;

    }

    if (blkid_parse_tag_string(token, &t, &v) != 0 || !t || !v)

      goto out;

    token = t;

    value = v;

  }

  dev = blkid_find_dev_with_tag(c, token, value);

  if (!dev)

    goto out;

  ret = dev->bid_name ? strdup(dev->bid_name) : NULL;

out:

  free(t);

  free(v);

  if (!cache)

    blkid_put_cache(c);

  return ret;

}

#ifdef TEST_PROGRAM

int main(int argc, char **argv)

{

  char *value;

  blkid_cache cache;

  blkid_init_debug(BLKID_DEBUG_ALL);

  if (argc != 2 && argc != 3) {

    fprintf(stderr, "Usage:\t%s tagname=value\n"

      "\t%s tagname devname\n"

      "Find which device holds a given token or\n"

      "Find what the value of a tag is in a device\n",

      argv[0], argv[0]);

    exit(1);

  }

  if (blkid_get_cache(&cache, "/dev/null") < 0) {

    fprintf(stderr, "Couldn't get blkid cache\n");

    exit(1);

  }

  if (argv[2]) {

    value = blkid_get_tag_value(cache, argv[1], argv[2]);

    printf("%s has tag %s=%s\n", argv[2], argv[1],

           value ? value : "<missing>");

  } else {

    value = blkid_get_devname(cache, argv[1], NULL);

    printf("%s has tag %s\n", value ? value : "<none>", argv[1]);

  }

  blkid_put_cache(cache);

  return value ? 0 : 1;

}

#endif