source: branches/2.2.5/mindi-busybox/e2fsprogs/old_e2fsprogs/blkid/resolve.c @ 1765

Last change on this file since 1765 was 1765, checked in by Bruno Cornec, 13 years ago

Update to busybox 1.7.2

  • Property svn:eol-style set to native
File size: 3.0 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * resolve.c - resolve names and tags into specific devices
4 *
5 * Copyright (C) 2001, 2003 Theodore Ts'o.
6 * Copyright (C) 2001 Andreas Dilger
7 *
8 * %Begin-Header%
9 * This file may be redistributed under the terms of the
10 * GNU Lesser General Public License.
11 * %End-Header%
12 */
13
14#include <stdio.h>
15#ifdef HAVE_UNISTD_H
16#include <unistd.h>
17#endif
18#include <stdlib.h>
19#include <fcntl.h>
20#include <string.h>
21#include <sys/types.h>
22#include <sys/stat.h>
23#include "blkidP.h"
24#include "probe.h"
25
26/*
27 * Find a tagname (e.g. LABEL or UUID) on a specific device.
28 */
29char *blkid_get_tag_value(blkid_cache cache, const char *tagname,
30              const char *devname)
31{
32    blkid_tag found;
33    blkid_dev dev;
34    blkid_cache c = cache;
35    char *ret = NULL;
36
37    DBG(DEBUG_RESOLVE, printf("looking for %s on %s\n", tagname, devname));
38
39    if (!devname)
40        return NULL;
41
42    if (!cache) {
43        if (blkid_get_cache(&c, NULL) < 0)
44            return NULL;
45    }
46
47    if ((dev = blkid_get_dev(c, devname, BLKID_DEV_NORMAL)) &&
48        (found = blkid_find_tag_dev(dev, tagname)))
49        ret = blkid_strdup(found->bit_val);
50
51    if (!cache)
52        blkid_put_cache(c);
53
54    return ret;
55}
56
57/*
58 * Locate a device name from a token (NAME=value string), or (name, value)
59 * pair.  In the case of a token, value is ignored.  If the "token" is not
60 * of the form "NAME=value" and there is no value given, then it is assumed
61 * to be the actual devname and a copy is returned.
62 */
63char *blkid_get_devname(blkid_cache cache, const char *token,
64            const char *value)
65{
66    blkid_dev dev;
67    blkid_cache c = cache;
68    char *t = 0, *v = 0;
69    char *ret = NULL;
70
71    if (!token)
72        return NULL;
73
74    if (!cache) {
75        if (blkid_get_cache(&c, NULL) < 0)
76            return NULL;
77    }
78
79    DBG(DEBUG_RESOLVE,
80        printf("looking for %s%s%s %s\n", token, value ? "=" : "",
81           value ? value : "", cache ? "in cache" : "from disk"));
82
83    if (!value) {
84        if (!strchr(token, '='))
85            return blkid_strdup(token);
86        blkid_parse_tag_string(token, &t, &v);
87        if (!t || !v)
88            goto errout;
89        token = t;
90        value = v;
91    }
92
93    dev = blkid_find_dev_with_tag(c, token, value);
94    if (!dev)
95        goto errout;
96
97    ret = blkid_strdup(blkid_dev_devname(dev));
98
99errout:
100    free(t);
101    free(v);
102    if (!cache) {
103        blkid_put_cache(c);
104    }
105    return ret;
106}
107
108#ifdef TEST_PROGRAM
109int main(int argc, char **argv)
110{
111    char *value;
112    blkid_cache cache;
113
114    blkid_debug_mask = DEBUG_ALL;
115    if (argc != 2 && argc != 3) {
116        fprintf(stderr, "Usage:\t%s tagname=value\n"
117            "\t%s tagname devname\n"
118            "Find which device holds a given token or\n"
119            "Find what the value of a tag is in a device\n",
120            argv[0], argv[0]);
121        exit(1);
122    }
123    if (blkid_get_cache(&cache, bb_dev_null) < 0) {
124        fprintf(stderr, "cannot get blkid cache\n");
125        exit(1);
126    }
127
128    if (argv[2]) {
129        value = blkid_get_tag_value(cache, argv[1], argv[2]);
130        printf("%s has tag %s=%s\n", argv[2], argv[1],
131               value ? value : "<missing>");
132    } else {
133        value = blkid_get_devname(cache, argv[1], NULL);
134        printf("%s has tag %s\n", value ? value : "<none>", argv[1]);
135    }
136    blkid_put_cache(cache);
137    return value ? 0 : 1;
138}
139#endif
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