| /* |
| * 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) { |
| 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, '=')) { |
| ret = blkid_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 = blkid_strdup(blkid_dev_devname(dev)); |
| |
| 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 |