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/* vi: set sw=4 ts=4: */
/*
* 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"
#include "probe.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(DEBUG_RESOLVE, printf("looking for %s on %s\n", tagname, devname));
if (!devname)
return NULL;
if (!cache) {
if (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 = blkid_strdup(found->bit_val);
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 = 0, *v = 0;
char *ret = NULL;
if (!token)
return NULL;
if (!cache) {
if (blkid_get_cache(&c, NULL) < 0)
return NULL;
}
DBG(DEBUG_RESOLVE,
printf("looking for %s%s%s %s\n", token, value ? "=" : "",
value ? value : "", cache ? "in cache" : "from disk"));
if (!value) {
if (!strchr(token, '='))
return blkid_strdup(token);
blkid_parse_tag_string(token, &t, &v);
if (!t || !v)
goto errout;
token = t;
value = v;
}
dev = blkid_find_dev_with_tag(c, token, value);
if (!dev)
goto errout;
ret = blkid_strdup(blkid_dev_devname(dev));
errout:
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_debug_mask = 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, bb_dev_null) < 0) {
fprintf(stderr, "cannot 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
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