/* * 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> #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" /* * 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: if (t) free(t); if (v) 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, "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