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author | bigbiff bigbiff <bigbiff@teamw.in> | 2013-02-23 02:55:50 +0100 |
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committer | bigbiff bigbiff <bigbiff@teamw.in> | 2013-02-25 15:06:46 +0100 |
commit | e60683a0d553b6488c564863f4e48954944fb0f8 (patch) | |
tree | 9364f97cb88b7c1359f5f06dfb32150a78168c31 /libblkid/resolve.c | |
parent | Fix building of updater for 4.2 environment (diff) | |
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Diffstat (limited to '')
-rw-r--r-- | libblkid/resolve.c | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/libblkid/resolve.c b/libblkid/resolve.c new file mode 100644 index 000000000..96749b3ec --- /dev/null +++ b/libblkid/resolve.c @@ -0,0 +1,131 @@ +/* + * 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(DEBUG_RESOLVE, printf("looking for %s on %s\n", 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 = 0, *v = 0; + char *ret = NULL; + + if (!token) + return NULL; + if (!cache && 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, '=')) { + ret = strdup(token); + goto out; + } + blkid_parse_tag_string(token, &t, &v); + if (!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(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 |