| /* |
| * resolve.c - resolve names and tags into specific devices |
| * |
| * Copyright (C) 2001 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> |
| #if 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" |
| |
| #ifdef DEBUG_RESOLVE |
| #define DBG(x) x |
| #else |
| #define DBG(x) |
| #endif |
| |
| |
| /* |
| * Find a tagname (e.g. LABEL or UUID) on a specific device. |
| */ |
| char *blkid_get_tagname_devname(blkid_cache cache, const char *tagname, |
| const char *devname) |
| { |
| blkid_tag found; |
| blkid_dev dev; |
| char *ret = NULL; |
| |
| DBG(printf("looking for %s on %s\n", tagname, devname)); |
| |
| if (!devname) |
| return NULL; |
| |
| if (!cache) |
| DBG(printf("no cache given, direct device probe\n")); |
| |
| if ((dev = blkid_get_devname(cache, devname)) && |
| (found = blkid_find_tag_dev(dev, tagname, NULL))) |
| ret = string_copy(found->bit_val); |
| |
| if (!cache) |
| blkid_free_dev(dev); |
| |
| 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. |
| * |
| * The string returned must be freed with string_free(). |
| */ |
| char *blkid_get_token(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; |
| |
| DBG(printf("looking for %s%c%s %s\n", token, value ? '=' : ' ', |
| value ? value : "", cache ? "in cache" : "from disk")); |
| |
| if (!cache) { |
| if (blkid_read_cache(&c, NULL) < 0) |
| c = blkid_new_cache(); |
| if (!c) |
| return NULL; |
| } |
| |
| if (!value) { |
| 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 = string_copy(blkid_devname_name(dev)); |
| |
| errout: |
| if (t) |
| free(t); |
| if (v) |
| free(v); |
| if (!cache) { |
| blkid_save_cache(c, NULL); |
| blkid_free_cache(c); |
| } |
| return (ret); |
| } |
| |
| #ifdef TEST_PROGRAM |
| int main(int argc, char **argv) |
| { |
| char *value; |
| |
| 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 (argv[2]) { |
| value = blkid_get_tagname_devname(NULL, argv[1], argv[2]); |
| printf("%s has tag %s=%s\n", argv[2], argv[1], |
| value ? value : "<missing>"); |
| } else { |
| value = blkid_get_token(NULL, argv[1], NULL); |
| printf("%s has tag %s\n", value ? value : "<none>", argv[1]); |
| } |
| return value ? 0 : 1; |
| } |
| #endif |