misc-utils/blkid.c

   1 /*
   2  * blkid.c - User command-line interface for libblkid
   3  *
   4  * Copyright (C) 2001 Andreas Dilger
   5  *
   6  * %Begin-Header%
   7  * This file may be redistributed under the terms of the
   8  * GNU Lesser General Public License.
   9  * %End-Header%
  10  */
  11
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <unistd.h>
  15 #include <string.h>
  16 #include <sys/types.h>
  17 #include <sys/stat.h>
  18 #include <fcntl.h>
  19 #include <termios.h>
  20 #include <errno.h>
  21 #ifdef HAVE_SYS_IOCTL_H
  22 #include <sys/ioctl.h>
  23 #endif
  24 #ifdef HAVE_GETOPT_H
  25 #include <getopt.h>
  26 #else
  27 extern int getopt(int argc, char * const argv[], const char *optstring);
  28 extern char *optarg;
  29 extern int optind;
  30 #endif
  31
  32 #define OUTPUT_VALUE_ONLY       0x0001
  33 #define OUTPUT_DEVICE_ONLY      0x0002
  34 #define OUTPUT_PRETTY_LIST      0x0004
  35 #define OUTPUT_UDEV_LIST        0x0008
  36
  37 #include <blkid.h>
  38
  39 #include "ismounted.h"
  40
  41 const char *progname = "blkid";
  42
  43 static void print_version(FILE *out)
  44 {
  45         fprintf(out, "%s from %s (libblkid %s, %s)\n",
  46                 progname, PACKAGE_STRING, LIBBLKID_VERSION, LIBBLKID_DATE);
  47 }
  48
  49 static void usage(int error)
  50 {
  51         FILE *out = error ? stderr : stdout;
  52
  53         print_version(out);
  54         fprintf(out,
  55                 "Usage:\n"
  56                 "  %1$s -L <label> | -U <uuid>\n\n"
  57                 "  %1$s [-c <file>] [-ghlLv] [-o format] [-s <tag>] \n"
  58                 "        [-t <token>] [-w <file>] [dev ...]\n\n"
  59                 "  %1$s -p [-O <offset>] [-S <size>] [-o format] <dev> [dev ...]\n\n"
  60                 "Options:\n"
  61                 "  -c <file>   cache file (default: /etc/blkid.tab, /dev/null = none)\n"
  62                 "  -h          print this usage message and exit\n"
  63                 "  -g          garbage collect the blkid cache\n"
  64                 "  -o <format> output format; can be one of:\n"
  65                 "              value, device, list, udev or full; (default: full)\n"
  66                 "  -s <tag>    show specified tag(s) (default show all tags)\n"
  67                 "  -t <token>  find device with a specific token (NAME=value pair)\n"
  68                 "  -l          lookup the the first device with arguments specified by -t\n"
  69                 "  -L <label>  convert LABEL to device name\n"
  70                 "  -U <uuid>   convert UUID to device name\n"
  71                 "  -v          print version and exit\n"
  72                 "  -w <file>   write cache to different file (/dev/null = no write)\n"
  73                 "  <dev>       specify device(s) to probe (default: all devices)\n\n"
  74                 "Low-level probing options:\n"
  75                 "  -p          switch to low-level mode (bypass cache)\n"
  76                 "  -S <bytes>  overwrite device size\n"
  77                 "  -O <bytes>  probe at the given offset\n"
  78                 "  -u <list>   filter by \"usage\" (e.g. -u filesystem,raid)\n"
  79                 "  -n <list>   filter by filesystem type (e.g. -n vfat,ext3)\n"
  80                 "\n",
  81                                 progname);
  82
  83         exit(error);
  84 }
  85
  86 /*
  87  * This function does "safe" printing.  It will convert non-printable
  88  * ASCII characters using '^' and M- notation.
  89  */
  90 static void safe_print(const char *cp, int len)
  91 {
  92         unsigned char   ch;
  93
  94         if (len < 0)
  95                 len = strlen(cp);
  96
  97         while (len--) {
  98                 ch = *cp++;
  99                 if (ch > 128) {
 100                         fputs("M-", stdout);
 101                         ch -= 128;
 102                 }
 103                 if ((ch < 32) || (ch == 0x7f)) {
 104                         fputc('^', stdout);
 105                         ch ^= 0x40; /* ^@, ^A, ^B; ^? for DEL */
 106                 }
 107                 fputc(ch, stdout);
 108         }
 109 }
 110
 111 static int get_terminal_width(void)
 112 {
 113 #ifdef TIOCGSIZE
 114         struct ttysize  t_win;
 115 #endif
 116 #ifdef TIOCGWINSZ
 117         struct winsize  w_win;
 118 #endif
 119         const char      *cp;
 120
 121 #ifdef TIOCGSIZE
 122         if (ioctl (0, TIOCGSIZE, &t_win) == 0)
 123                 return (t_win.ts_cols);
 124 #endif
 125 #ifdef TIOCGWINSZ
 126         if (ioctl (0, TIOCGWINSZ, &w_win) == 0)
 127                 return (w_win.ws_col);
 128 #endif
 129         cp = getenv("COLUMNS");
 130         if (cp)
 131                 return strtol(cp, NULL, 10);
 132         return 80;
 133 }
 134
 135 static int pretty_print_word(const char *str, int max_len,
 136                              int left_len, int overflow_nl)
 137 {
 138         int len = strlen(str) + left_len;
 139         int ret = 0;
 140
 141         fputs(str, stdout);
 142         if (overflow_nl && len > max_len) {
 143                 fputc('\n', stdout);
 144                 len = 0;
 145         } else if (len > max_len)
 146                 ret = len - max_len;
 147         do
 148                 fputc(' ', stdout);
 149         while (len++ < max_len);
 150         return ret;
 151 }
 152
 153 static void pretty_print_line(const char *device, const char *fs_type,
 154                               const char *label, const char *mtpt,
 155                               const char *uuid)
 156 {
 157         static int device_len = 10, fs_type_len = 7;
 158         static int label_len = 8, mtpt_len = 14;
 159         static int term_width = -1;
 160         int len, w;
 161
 162         if (term_width < 0)
 163                 term_width = get_terminal_width();
 164
 165         if (term_width > 80) {
 166                 term_width -= 80;
 167                 w = term_width / 10;
 168                 if (w > 8)
 169                         w = 8;
 170                 term_width -= 2*w;
 171                 label_len += w;
 172                 fs_type_len += w;
 173                 w = term_width/2;
 174                 device_len += w;
 175                 mtpt_len +=w;
 176         }
 177
 178         len = pretty_print_word(device, device_len, 0, 1);
 179         len = pretty_print_word(fs_type, fs_type_len, len, 0);
 180         len = pretty_print_word(label, label_len, len, 0);
 181         len = pretty_print_word(mtpt, mtpt_len, len, 0);
 182         fputs(uuid, stdout);
 183         fputc('\n', stdout);
 184 }
 185
 186 static void pretty_print_dev(blkid_dev dev)
 187 {
 188         blkid_tag_iterate       iter;
 189         const char              *type, *value, *devname;
 190         const char              *uuid = "", *fs_type = "", *label = "";
 191         int                     len, mount_flags;
 192         char                    mtpt[80];
 193         int                     retval;
 194
 195         if (dev == NULL) {
 196                 pretty_print_line("device", "fs_type", "label",
 197                                   "mount point", "UUID");
 198                 for (len=get_terminal_width()-1; len > 0; len--)
 199                         fputc('-', stdout);
 200                 fputc('\n', stdout);
 201                 return;
 202         }
 203
 204         devname = blkid_dev_devname(dev);
 205         if (access(devname, F_OK))
 206                 return;
 207
 208         /* Get the uuid, label, type */
 209         iter = blkid_tag_iterate_begin(dev);
 210         while (blkid_tag_next(iter, &type, &value) == 0) {
 211                 if (!strcmp(type, "UUID"))
 212                         uuid = value;
 213                 if (!strcmp(type, "TYPE"))
 214                         fs_type = value;
 215                 if (!strcmp(type, "LABEL"))
 216                         label = value;
 217         }
 218         blkid_tag_iterate_end(iter);
 219
 220         /* Get the mount point */
 221         mtpt[0] = 0;
 222         retval = check_mount_point(devname, &mount_flags, mtpt, sizeof(mtpt));
 223         if (retval == 0) {
 224                 if (mount_flags & MF_MOUNTED) {
 225                         if (!mtpt[0])
 226                                 strcpy(mtpt, "(mounted, mtpt unknown)");
 227                 } else if (mount_flags & MF_BUSY)
 228                         strcpy(mtpt, "(in use)");
 229                 else
 230                         strcpy(mtpt, "(not mounted)");
 231         }
 232
 233         pretty_print_line(devname, fs_type, label, mtpt, uuid);
 234 }
 235
 236 static void print_udev_format(const char *name, const char *value, size_t sz)
 237 {
 238         char enc[265], safe[256];
 239
 240         *safe = *enc = '\0';
 241
 242         if (!strcmp(name, "TYPE") || !strcmp(name, "VERSION")) {
 243                 blkid_encode_string(value, enc, sizeof(enc));
 244                 printf("ID_FS_%s=%s\n", name, enc);
 245
 246         } else if (!strcmp(name, "UUID") ||
 247                  !strcmp(name, "LABEL") ||
 248                  !strcmp(name, "UUID_SUB")) {
 249
 250                 blkid_safe_string(value, safe, sizeof(safe));
 251                 printf("ID_FS_%s=%s\n", name, safe);
 252
 253                 blkid_encode_string(value, enc, sizeof(enc));
 254                 printf("ID_FS_%s_ENC=%s\n", name, enc);
 255
 256         } else if (!strcmp(name, "PTTYPE")) {
 257                 printf("ID_PART_TABLE_TYPE=%s\n", value);
 258
 259         } else if (!strcmp(name, "PART_ENTRY_NAME") ||
 260                   !strcmp(name, "PART_ENTRY_TYPE")) {
 261
 262                 blkid_safe_string(value, safe, sizeof(safe));
 263                 printf("ID_%s=%s\n", name, safe);
 264
 265                 blkid_encode_string(value, enc, sizeof(enc));
 266                 printf("ID_%s_ENC=%s\n", name, enc);
 267
 268         } else if (!strncmp(name, "PART_ENTRY_", 11))
 269                 printf("ID_%s=%s\n", name, value);
 270
 271         else
 272                 printf("ID_FS_%s=%s\n", name, value);
 273 }
 274
 275 static int has_item(char *ary[], const char *item)
 276 {
 277         char **p;
 278
 279         for (p = ary; *p != NULL; p++)
 280                 if (!strcmp(item, *p))
 281                         return 1;
 282         return 0;
 283 }
 284
 285 static void print_value(int output, int num, const char *devname,
 286                         const char *value, const char *name, size_t valsz)
 287 {
 288         if (output & OUTPUT_VALUE_ONLY) {
 289                 fputs(value, stdout);
 290                 fputc('\n', stdout);
 291
 292         } else if (output & OUTPUT_UDEV_LIST) {
 293                 print_udev_format(name, value, valsz);
 294
 295         } else {
 296                 if (num == 1 && devname)
 297                         printf("%s: ", devname);
 298                 fputs(name, stdout);
 299                 fputs("=\"", stdout);
 300                 safe_print(value, valsz);
 301                 fputs("\" ", stdout);
 302         }
 303 }
 304
 305 static void print_tags(blkid_dev dev, char *show[], int output)
 306 {
 307         blkid_tag_iterate       iter;
 308         const char              *type, *value, *devname;
 309         int                     num = 1;
 310
 311         if (!dev)
 312                 return;
 313
 314         if (output & OUTPUT_PRETTY_LIST) {
 315                 pretty_print_dev(dev);
 316                 return;
 317         }
 318
 319         devname = blkid_dev_devname(dev);
 320
 321         if (output & OUTPUT_DEVICE_ONLY) {
 322                 printf("%s\n", devname);
 323                 return;
 324         }
 325
 326         iter = blkid_tag_iterate_begin(dev);
 327         while (blkid_tag_next(iter, &type, &value) == 0) {
 328                 if (show[0] && !has_item(show, type))
 329                         continue;
 330                 print_value(output, num++, devname, value, type, strlen(value));
 331         }
 332         blkid_tag_iterate_end(iter);
 333
 334         if (num > 1 && !(output & (OUTPUT_VALUE_ONLY | OUTPUT_UDEV_LIST)))
 335                 printf("\n");
 336 }
 337
 338
 339 static int append_str(char **res, size_t *sz, const char *a, const char *b)
 340 {
 341         char *str = *res;
 342         size_t asz = a ? strlen(a) : 0;
 343         size_t bsz = b ? strlen(b) : 0;
 344         size_t len = *sz + asz + bsz;
 345
 346         if (!len)
 347                 return -1;
 348
 349         str = realloc(str, len + 1);
 350         if (!str) {
 351                 free(*res);
 352                 return -1;
 353         }
 354         *res = str;
 355         str += *sz;
 356
 357         if (a) {
 358                 memcpy(str, a, asz);
 359                 str += asz;
 360         }
 361         if (b) {
 362                 memcpy(str, b, bsz);
 363                 str += bsz;
 364         }
 365         *str = '\0';
 366         *sz = len;
 367         return 0;
 368 }
 369
 370 /*
 371  * Compose and print ID_FS_AMBIVALENT for udev
 372  */
 373 static int print_udev_ambivalent(blkid_probe pr)
 374 {
 375         char *val = NULL;
 376         size_t valsz = 0;
 377         int count = 0, rc = -1;
 378
 379         while (!blkid_do_probe(pr)) {
 380                 const char *usage = NULL, *type = NULL, *version = NULL;
 381                 char enc[256];
 382
 383                 blkid_probe_lookup_value(pr, "USAGE", &usage, NULL);
 384                 blkid_probe_lookup_value(pr, "TYPE", &type, NULL);
 385                 blkid_probe_lookup_value(pr, "VERSION", &version, NULL);
 386
 387                 if (!usage || !type)
 388                         continue;
 389
 390                 blkid_encode_string(usage, enc, sizeof(enc));
 391                 if (append_str(&val, &valsz, enc, ":"))
 392                         goto done;
 393
 394                 blkid_encode_string(type, enc, sizeof(enc));
 395                 if (append_str(&val, &valsz, enc, version ? ":" : " "))
 396                         goto done;
 397
 398                 if (version) {
 399                         blkid_encode_string(version, enc, sizeof(enc));
 400                         if (append_str(&val, &valsz, enc, " "))
 401                                 goto done;
 402                 }
 403                 count++;
 404         }
 405
 406         if (count > 1) {
 407                 *(val + valsz - 1) = '\0';              /* rem tailing whitespace */
 408                 printf("ID_FS_AMBIVALEN=%s\n", val);
 409                 rc = 0;
 410         }
 411 done:
 412         free(val);
 413         return rc;
 414 }
 415
 416 static int lowprobe_device(blkid_probe pr, const char *devname, char *show[],
 417                         int output, blkid_loff_t offset, blkid_loff_t size)
 418 {
 419         const char *data;
 420         const char *name;
 421         int nvals = 0, n, num = 1, has_pt = 0;
 422         size_t len;
 423         int fd;
 424         int rc = 0;
 425         struct stat st;
 426
 427         fd = open(devname, O_RDONLY);
 428         if (fd < 0) {
 429                 fprintf(stderr, "error: %s: %s\n", devname, strerror(errno));
 430                 return 2;
 431         }
 432         if (blkid_probe_set_device(pr, fd, offset, size))
 433                 goto done;
 434
 435         if (fstat(fd, &st))
 436                 goto done;
 437         /*
 438          * partitions probing
 439          */
 440         blkid_probe_enable_superblocks(pr, 0);  /* enabled by default ;-( */
 441
 442         blkid_probe_enable_partitions(pr, 1);
 443
 444         /* This is for PART_ENTRY_{UUID,NAME,TYPE,...} values and it will
 445          * open() whole-disk device.
 446          */
 447         blkid_probe_set_partitions_flags(pr, BLKID_PARTS_ENTRY_DETAILS);
 448
 449         rc = blkid_do_fullprobe(pr);
 450         blkid_probe_enable_partitions(pr, 0);
 451
 452         if (rc < 0)
 453                 goto done;      /* -1 = error, 1 = nothing, 0 = succes */
 454
 455         if (blkid_probe_lookup_value(pr, "PTTYPE", NULL, NULL) == 0)
 456                 /* partition table detected */
 457                 has_pt = 1;
 458
 459         /*
 460          * filesystems/raids probing
 461          *
 462          * Q: Why do we try to probe for FS/RAID on device with partiton table?
 463          *
 464          * A: For some devices the kernel creates partitions because it is too
 465          *    dumb to find out, that the device contains a RAID signature or
 466          *    other metadata that signifies, that this device should not be
 467          *    handled.
 468          *
 469          *    Many RAID signatures are at the end of the device, or at least
 470          *    still allow that the volume contains a partition table at the
 471          *    beginning of the device, which the kernel will find. Udev needs
 472          *    to look at the disk, if there are such RAID signatures, and then
 473          *    it needs to handle it, and in many cases just kill all the
 474          *    wrongly kernel-created partitions.
 475          *
 476          * -- Kay Sievers
 477          *    http://thread.gmane.org/gmane.linux.utilities.util-linux-ng/2888/focus=2890
 478          *
 479          * This all is unncecessary for very small devices (<= 1.44MiB).
 480          */
 481         if (has_pt == 0 || S_ISCHR(st.st_mode) ||
 482             blkid_probe_get_size(pr) > 1024 * 1440) {
 483                 /*
 484                  * filesystems/RAIDs probing
 485                  */
 486                 blkid_probe_enable_superblocks(pr, 1);
 487
 488                 rc = blkid_do_safeprobe(pr);
 489                 if (rc < 0)
 490                         goto done;
 491         }
 492
 493         nvals = blkid_probe_numof_values(pr);
 494
 495         if (output & OUTPUT_DEVICE_ONLY) {
 496                 printf("%s\n", devname);
 497                 goto done;
 498         }
 499
 500         for (n = 0; n < nvals; n++) {
 501                 if (blkid_probe_get_value(pr, n, &name, &data, &len))
 502                         continue;
 503                 if (show[0] && !has_item(show, name))
 504                         continue;
 505                 len = strnlen((char *) data, len);
 506                 print_value(output, num++, devname, (char *) data, name, len);
 507         }
 508
 509         if (nvals >= 1 && !(output & (OUTPUT_VALUE_ONLY | OUTPUT_UDEV_LIST)))
 510                 printf("\n");
 511 done:
 512         if (rc == -2) {
 513                 if (output & OUTPUT_UDEV_LIST)
 514                         print_udev_ambivalent(pr);
 515                 else
 516                         fprintf(stderr,
 517                                 "%s: ambivalent result (probably more "
 518                                 "filesystems on the device, use wipefs(8) "
 519                                 "to see more details)\n",
 520                                 devname);
 521         }
 522         close(fd);
 523         return !nvals ? 2 : 0;
 524 }
 525
 526 /* converts comma separated list to BLKID_USAGE_* mask */
 527 static int list_to_usage(const char *list, int *flag)
 528 {
 529         int mask = 0;
 530         const char *word = NULL, *p = list;
 531
 532         if (p && strncmp(p, "no", 2) == 0) {
 533                 *flag = BLKID_FLTR_NOTIN;
 534                 p += 2;
 535         }
 536         if (!p || !*p)
 537                 goto err;
 538         while(p) {
 539                 word = p;
 540                 p = strchr(p, ',');
 541                 if (p)
 542                         p++;
 543                 if (!strncmp(word, "filesystem", 10))
 544                         mask |= BLKID_USAGE_FILESYSTEM;
 545                 else if (!strncmp(word, "raid", 4))
 546                         mask |= BLKID_USAGE_RAID;
 547                 else if (!strncmp(word, "crypto", 6))
 548                         mask |= BLKID_USAGE_CRYPTO;
 549                 else if (!strncmp(word, "other", 5))
 550                         mask |= BLKID_USAGE_OTHER;
 551                 else
 552                         goto err;
 553         }
 554         return mask;
 555 err:
 556         *flag = 0;
 557         fprintf(stderr, "unknown kerword in -u <list> argument: '%s'\n",
 558                         word ? word : list);
 559         exit(4);
 560 }
 561
 562 /* converts comma separated list to types[] */
 563 static char **list_to_types(const char *list, int *flag)
 564 {
 565         int i;
 566         const char *p = list;
 567         char **res;
 568
 569         if (p && strncmp(p, "no", 2) == 0) {
 570                 *flag = BLKID_FLTR_NOTIN;
 571                 p += 2;
 572         }
 573         if (!p || !*p) {
 574                 fprintf(stderr, "error: -u <list> argument is empty\n");
 575                 goto err;
 576         }
 577         for (i = 1; p && (p = strchr(p, ',')); i++, p++);
 578
 579         res = calloc(i + 1, sizeof(char *));
 580         if (!res)
 581                 goto err_mem;
 582         p = *flag & BLKID_FLTR_NOTIN ? list + 2 : list;
 583         i = 0;
 584
 585         while(p) {
 586                 const char *word = p;
 587                 p = strchr(p, ',');
 588                 res[i] = p ? strndup(word, p - word) : strdup(word);
 589                 if (!res[i++])
 590                         goto err_mem;
 591                 if (p)
 592                         p++;
 593         }
 594         res[i] = NULL;
 595         return res;
 596 err_mem:
 597         fprintf(stderr, "out of memory\n");
 598 err:
 599         *flag = 0;
 600         free(res);
 601         exit(4);
 602 }
 603
 604 static void free_types_list(char *list[])
 605 {
 606         char **n;
 607
 608         if (!list)
 609                 return;
 610         for (n = list; *n; n++)
 611                 free(*n);
 612         free(list);
 613 }
 614
 615 int main(int argc, char **argv)
 616 {
 617         blkid_cache cache = NULL;
 618         char *devices[128] = { NULL, };
 619         char *show[128] = { NULL, };
 620         char *search_type = NULL, *search_value = NULL;
 621         char *read = NULL;
 622         char *write = NULL;
 623         int fltr_usage = 0;
 624         char **fltr_type = NULL;
 625         int fltr_flag = BLKID_FLTR_ONLYIN;
 626         unsigned int numdev = 0, numtag = 0;
 627         int version = 0;
 628         int err = 4;
 629         unsigned int i;
 630         int output_format = 0;
 631         int lookup = 0, gc = 0, lowprobe = 0, eval = 0;
 632         int c;
 633         blkid_loff_t offset = 0, size = 0;
 634
 635         show[0] = NULL;
 636
 637         while ((c = getopt (argc, argv, "c:f:ghlL:n:o:O:ps:S:t:u:U:w:v")) != EOF)
 638                 switch (c) {
 639                 case 'c':
 640                         if (optarg && !*optarg)
 641                                 read = NULL;
 642                         else
 643                                 read = optarg;
 644                         if (!write)
 645                                 write = read;
 646                         break;
 647                 case 'L':
 648                         eval++;
 649                         search_value = strdup(optarg);
 650                         search_type = strdup("LABEL");
 651                         break;
 652                 case 'n':
 653                         if (fltr_usage) {
 654                                 fprintf(stderr, "error: -u and -n options are mutually exclusive\n");
 655                                 exit(4);
 656                         }
 657                         fltr_type = list_to_types(optarg, &fltr_flag);
 658                         break;
 659                 case 'u':
 660                         if (fltr_type) {
 661                                 fprintf(stderr, "error: -u and -n options are mutually exclusive\n");
 662                                 exit(4);
 663                         }
 664                         fltr_usage = list_to_usage(optarg, &fltr_flag);
 665                         break;
 666                 case 'U':
 667                         eval++;
 668                         search_value = strdup(optarg);
 669                         search_type = strdup("UUID");
 670                         break;
 671                 case 'l':
 672                         lookup++;
 673                         break;
 674                 case 'g':
 675                         gc = 1;
 676                         break;
 677                 case 'o':
 678                         if (!strcmp(optarg, "value"))
 679                                 output_format = OUTPUT_VALUE_ONLY;
 680                         else if (!strcmp(optarg, "device"))
 681                                 output_format = OUTPUT_DEVICE_ONLY;
 682                         else if (!strcmp(optarg, "list"))
 683                                 output_format = OUTPUT_PRETTY_LIST;
 684                         else if (!strcmp(optarg, "udev"))
 685                                 output_format = OUTPUT_UDEV_LIST;
 686                         else if (!strcmp(optarg, "full"))
 687                                 output_format = 0;
 688                         else {
 689                                 fprintf(stderr, "Invalid output format %s. "
 690                                         "Choose from value,\n\t"
 691                                         "device, list, udev or full\n", optarg);
 692                                 exit(4);
 693                         }
 694                         break;
 695                 case 'O':
 696                         offset = strtoll(optarg, NULL, 10);
 697                         break;
 698                 case 'p':
 699                         lowprobe++;
 700                         break;
 701                 case 's':
 702                         if (numtag + 1 >= sizeof(show) / sizeof(*show)) {
 703                                 fprintf(stderr, "Too many tags specified\n");
 704                                 usage(err);
 705                         }
 706                         show[numtag++] = optarg;
 707                         show[numtag] = NULL;
 708                         break;
 709                 case 'S':
 710                         size = strtoll(optarg, NULL, 10);
 711                         break;
 712                 case 't':
 713                         if (search_type) {
 714                                 fprintf(stderr, "Can only search for "
 715                                                 "one NAME=value pair\n");
 716                                 usage(err);
 717                         }
 718                         if (blkid_parse_tag_string(optarg,
 719                                                    &search_type,
 720                                                    &search_value)) {
 721                                 fprintf(stderr, "-t needs NAME=value pair\n");
 722                                 usage(err);
 723                         }
 724                         break;
 725                 case 'v':
 726                         version = 1;
 727                         break;
 728                 case 'w':
 729                         if (optarg && !*optarg)
 730                                 write = NULL;
 731                         else
 732                                 write = optarg;
 733                         break;
 734                 case 'h':
 735                         err = 0;
 736                 default:
 737                         usage(err);
 738                 }
 739
 740         while (optind < argc)
 741                 devices[numdev++] = argv[optind++];
 742
 743         if (version) {
 744                 print_version(stdout);
 745                 goto exit;
 746         }
 747
 748         /* convert LABEL/UUID lookup to evaluate request */
 749         if (lookup && output_format == OUTPUT_DEVICE_ONLY && search_type &&
 750             (!strcmp(search_type, "LABEL") || !strcmp(search_type, "UUID"))) {
 751                 eval++;
 752                 lookup = 0;
 753         }
 754
 755         if (!lowprobe && !eval && blkid_get_cache(&cache, read) < 0)
 756                 goto exit;
 757
 758         if (gc) {
 759                 blkid_gc_cache(cache);
 760                 err = 0;
 761                 goto exit;
 762         }
 763         err = 2;
 764
 765         if (eval == 0 && output_format & OUTPUT_PRETTY_LIST) {
 766                 if (lowprobe) {
 767                         fprintf(stderr, "The low-level probing mode does not "
 768                                         "support 'list' output format\n");
 769                         exit(4);
 770                 }
 771                 pretty_print_dev(NULL);
 772         }
 773
 774         if (lowprobe) {
 775                 /*
 776                  * Low-level API
 777                  */
 778                 blkid_probe pr;
 779
 780                 if (!numdev) {
 781                         fprintf(stderr, "The low-level probing mode "
 782                                         "requires a device\n");
 783                         exit(4);
 784                 }
 785                 pr = blkid_new_probe();
 786                 if (!pr)
 787                         goto exit;
 788
 789                 blkid_probe_set_superblocks_flags(pr,
 790                                 BLKID_SUBLKS_LABEL | BLKID_SUBLKS_UUID |
 791                                 BLKID_SUBLKS_TYPE | BLKID_SUBLKS_SECTYPE |
 792                                 BLKID_SUBLKS_USAGE | BLKID_SUBLKS_VERSION);
 793
 794                 if (fltr_usage &&
 795                     blkid_probe_filter_superblocks_usage(pr, fltr_flag, fltr_usage))
 796                         goto exit;
 797                 else if (fltr_type &&
 798                     blkid_probe_filter_superblocks_type(pr, fltr_flag, fltr_type))
 799                         goto exit;
 800
 801                 for (i = 0; i < numdev; i++)
 802                         err = lowprobe_device(pr, devices[i], show,
 803                                         output_format, offset, size);
 804                 blkid_free_probe(pr);
 805         } else if (eval) {
 806                 /*
 807                  * Evaluate API
 808                  */
 809                 char *res = blkid_evaluate_tag(search_type, search_value, NULL);
 810                 if (res) {
 811                         err = 0;
 812                         printf("%s\n", res);
 813                 }
 814         } else if (lookup) {
 815                 /*
 816                  * Classic (cache based) API
 817                  */
 818                 blkid_dev dev;
 819
 820                 if (!search_type) {
 821                         fprintf(stderr, "The lookup option requires a "
 822                                 "search type specified using -t\n");
 823                         exit(4);
 824                 }
 825                 /* Load any additional devices not in the cache */
 826                 for (i = 0; i < numdev; i++)
 827                         blkid_get_dev(cache, devices[i], BLKID_DEV_NORMAL);
 828
 829                 if ((dev = blkid_find_dev_with_tag(cache, search_type,
 830                                                    search_value))) {
 831                         print_tags(dev, show, output_format);
 832                         err = 0;
 833                 }
 834         /* If we didn't specify a single device, show all available devices */
 835         } else if (!numdev) {
 836                 blkid_dev_iterate       iter;
 837                 blkid_dev               dev;
 838
 839                 blkid_probe_all(cache);
 840
 841                 iter = blkid_dev_iterate_begin(cache);
 842                 blkid_dev_set_search(iter, search_type, search_value);
 843                 while (blkid_dev_next(iter, &dev) == 0) {
 844                         dev = blkid_verify(cache, dev);
 845                         if (!dev)
 846                                 continue;
 847                         print_tags(dev, show, output_format);
 848                         err = 0;
 849                 }
 850                 blkid_dev_iterate_end(iter);
 851         /* Add all specified devices to cache (optionally display tags) */
 852         } else for (i = 0; i < numdev; i++) {
 853                 blkid_dev dev = blkid_get_dev(cache, devices[i],
 854                                                   BLKID_DEV_NORMAL);
 855
 856                 if (dev) {
 857                         if (search_type &&
 858                             !blkid_dev_has_tag(dev, search_type,
 859                                                search_value))
 860                                 continue;
 861                         print_tags(dev, show, output_format);
 862                         err = 0;
 863                 }
 864         }
 865
 866 exit:
 867         free(search_type);
 868         free(search_value);
 869         free_types_list(fltr_type);
 870         if (!lowprobe && !eval)
 871                 blkid_put_cache(cache);
 872         return err;
 873 }