logutil.c

   1 /*
   2  * Copyright (C) 2007 The Android Open Source Project
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  *      http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  */
  16
  17
  18 #include <stdio.h>
  19 #include <stdlib.h>
  20 #include <stdbool.h>
  21 #include <stdarg.h>
  22 #include <string.h>
  23 #include <unistd.h>
  24 #include <fcntl.h>
  25 #include <time.h>
  26 #include <sys/time.h>
  27 #include <ctype.h>
  28 #include <errno.h>
  29 #include <assert.h>
  30 #include <sys/stat.h>
  31 #include <arpa/inet.h>
  32
  33
  34 #include <logger.h>
  35 #include <logprint.h>
  36
  37 #define DEFAULT_LOG_ROTATE_SIZE_KBYTES 16
  38 #define DEFAULT_MAX_ROTATED_LOGS 4
  39
  40 #define LOG_FILE_DIR    "/dev/log_"
  41
  42 static log_format* g_logformat;
  43 static bool g_nonblock = false;
  44 static int g_tail_lines = 0;
  45
  46 static const char * g_output_filename = NULL;
  47 static int g_log_rotate_size_kbytes = 0;                   // 0 means "no log rotation"
  48 static int g_max_rotated_logs = DEFAULT_MAX_ROTATED_LOGS; // 0 means "unbounded"
  49 static int g_outfd = -1;
  50 static off_t g_out_byte_count = 0;
  51 static int g_dev_count = 0;
  52
  53 struct queued_entry_t {
  54         union {
  55                 unsigned char buf[LOGGER_ENTRY_MAX_LEN + 1] __attribute__((aligned(4)));
  56                 struct logger_entry entry __attribute__((aligned(4)));
  57         };
  58         struct queued_entry_t* next;
  59 };
  60
  61 static int cmp(struct queued_entry_t* a, struct queued_entry_t* b)
  62 {
  63         int n = a->entry.sec - b->entry.sec;
  64         if (n != 0)
  65         {
  66                 return n;
  67         }
  68         return a->entry.nsec - b->entry.nsec;
  69 }
  70
  71
  72 struct log_device_t {
  73         char* device;
  74         int fd;
  75         bool printed;
  76         struct queued_entry_t* queue;
  77         struct log_device_t* next;
  78 };
  79
  80 static void enqueue(struct log_device_t* device, struct queued_entry_t* entry)
  81 {
  82         if( device->queue == NULL)
  83         {
  84                 device->queue = entry;
  85         }
  86         else
  87         {
  88                 struct queued_entry_t** e = &device->queue;
  89                 while(*e && cmp(entry, *e) >= 0 )
  90                 {
  91                         e = &((*e)->next);
  92                 }
  93                 entry->next = *e;
  94                 *e = entry;
  95     }
  96 }
  97
  98 static int open_logfile (const char *pathname)
  99 {
 100     return open(pathname, O_WRONLY | O_APPEND | O_CREAT, S_IRUSR | S_IWUSR);
 101 }
 102
 103 static void rotate_logs()
 104 {
 105     int err;
 106         int i;
 107         char file0[256]={0};
 108         char file1[256]={0};
 109
 110     // Can't rotate logs if we're not outputting to a file
 111     if (g_output_filename == NULL) {
 112         return;
 113     }
 114
 115     close(g_outfd);
 116
 117     for (i = g_max_rotated_logs ; i > 0 ; i--)
 118         {
 119                 snprintf(file1, 255, "%s.%d", g_output_filename, i);
 120
 121                 if (i - 1 == 0) {
 122                         snprintf(file0, 255, "%s", g_output_filename);
 123                 } else {
 124                         snprintf(file0, 255, "%s.%d", g_output_filename, i - 1);
 125                 }
 126
 127                 err = rename (file0, file1);
 128
 129                 if (err < 0 && errno != ENOENT) {
 130                         perror("while rotating log files");
 131                 }
 132     }
 133
 134     g_outfd = open_logfile (g_output_filename);
 135
 136     if (g_outfd < 0) {
 137         perror ("couldn't open output file");
 138         exit(-1);
 139     }
 140
 141     g_out_byte_count = 0;
 142
 143 }
 144
 145
 146 static void processBuffer(struct log_device_t* dev, struct logger_entry *buf)
 147 {
 148         int bytes_written = 0;
 149         int err;
 150         log_entry entry;
 151         char mgs_buf[1024];
 152
 153         err = log_process_log_buffer(buf, &entry);
 154
 155         if (err < 0) {
 156                 goto error;
 157         }
 158
 159         if (log_should_print_line(g_logformat, entry.tag, entry.priority)) {
 160                 if (false && g_dev_count > 1) {
 161                         // FIXME
 162                         mgs_buf[0] = dev->device[0];
 163                         mgs_buf[1] = ' ';
 164                         bytes_written = write(g_outfd, mgs_buf, 2);
 165                         if (bytes_written < 0)
 166                         {
 167                                 perror("output error");
 168                                 exit(-1);
 169                         }
 170                 }
 171
 172                 bytes_written = log_print_log_line(g_logformat, g_outfd, &entry);
 173
 174                 if (bytes_written < 0)
 175                 {
 176                         perror("output error");
 177                         exit(-1);
 178                 }
 179         }
 180
 181         g_out_byte_count += bytes_written;
 182
 183     if (g_log_rotate_size_kbytes > 0 && (g_out_byte_count / 1024) >= g_log_rotate_size_kbytes)
 184         {
 185                 rotate_logs();
 186         }
 187
 188 error:
 189         //fprintf (stderr, "Error processing record\n");
 190         return;
 191 }
 192
 193 static void chooseFirst(struct log_device_t* dev, struct log_device_t** firstdev)
 194 {
 195         for (*firstdev = NULL; dev != NULL; dev = dev->next) {
 196                 if (dev->queue != NULL && (*firstdev == NULL || cmp(dev->queue, (*firstdev)->queue) < 0))
 197                 {
 198                         *firstdev = dev;
 199                 }
 200         }
 201 }
 202
 203 static void maybePrintStart(struct log_device_t* dev) {
 204         if (!dev->printed) {
 205                 dev->printed = true;
 206                 if (g_dev_count > 1 ) {
 207                         char buf[1024];
 208                         snprintf(buf, sizeof(buf), "--------- beginning of %s\n", dev->device);
 209                         if (write(g_outfd, buf, strlen(buf)) < 0) {
 210                                 perror("output error");
 211                                 exit(-1);
 212                         }
 213                 }
 214         }
 215 }
 216
 217 static void skipNextEntry(struct log_device_t* dev) {
 218         maybePrintStart(dev);
 219         struct queued_entry_t* entry = dev->queue;
 220         dev->queue = entry->next;
 221         free(entry);
 222 }
 223
 224 static void printNextEntry(struct log_device_t* dev)
 225 {
 226         maybePrintStart(dev);
 227         processBuffer(dev, &dev->queue->entry);
 228         skipNextEntry(dev);
 229 }
 230
 231
 232 static void read_log_lines(struct log_device_t* devices)
 233 {
 234         struct log_device_t* dev;
 235         int max = 0;
 236         int ret;
 237         int queued_lines = 0;
 238         bool sleep = false; // for exit immediately when log buffer is empty and g_nonblock value is true.
 239
 240         int result;
 241         fd_set readset;
 242
 243         for (dev=devices; dev; dev = dev->next) {
 244                 if (dev->fd > max) {
 245                         max = dev->fd;
 246                 }
 247         }
 248
 249         while (1) {
 250                 do {
 251                         struct timeval timeout = { 0, 5000 /* 5ms */ }; // If we oversleep it's ok, i.e. ignore EINTR.
 252                         FD_ZERO(&readset);
 253                         for (dev=devices; dev; dev = dev->next) {
 254                                 FD_SET(dev->fd, &readset);
 255                         }
 256                         result = select(max + 1, &readset, NULL, NULL, sleep ? NULL : &timeout);
 257                 } while (result == -1 && errno == EINTR);
 258
 259         if (result >= 0) {
 260             for (dev=devices; dev; dev = dev->next) {
 261                 if (FD_ISSET(dev->fd, &readset)) {
 262                     struct queued_entry_t* entry = (struct queued_entry_t *)malloc(sizeof( struct queued_entry_t));
 263                                         if (entry == NULL) {
 264                                                 fprintf(stderr,"Can't malloc queued_entry\n");
 265                                                 exit(-1);
 266                                         }
 267                                         entry->next = NULL;
 268
 269                     /* NOTE: driver guarantees we read exactly one full entry */
 270                     ret = read(dev->fd, entry->buf, LOGGER_ENTRY_MAX_LEN);
 271                     if (ret < 0) {
 272                         if (errno == EINTR) {
 273                             free(entry);
 274                             goto next;
 275                         }
 276                         if (errno == EAGAIN) {
 277                             free(entry);
 278                             break;
 279                         }
 280                         perror("dlogutil read");
 281                         exit(EXIT_FAILURE);
 282                     }
 283                     else if (!ret) {
 284                         fprintf(stderr, "read: Unexpected EOF!\n");
 285                         exit(EXIT_FAILURE);
 286                     }
 287
 288                     entry->entry.msg[entry->entry.len] = '\0';
 289
 290                     enqueue(dev, entry);
 291                     ++queued_lines;
 292                 }
 293             }
 294
 295             if (result == 0) {
 296                 // we did our short timeout trick and there's nothing new
 297                 // print everything we have and wait for more data
 298                 sleep = true;
 299                 while (true) {
 300                     chooseFirst(devices, &dev);
 301                     if (dev == NULL) {
 302                         break;
 303                     }
 304                     if (g_tail_lines == 0 || queued_lines <= g_tail_lines) {
 305                         printNextEntry(dev);
 306                     } else {
 307                         skipNextEntry(dev);
 308                     }
 309                     --queued_lines;
 310                 }
 311
 312                 // the caller requested to just dump the log and exit
 313                 if (g_nonblock) {
 314                     exit(0);
 315                 }
 316             } else {
 317                 // print all that aren't the last in their list
 318                 sleep = false;
 319                 while (g_tail_lines == 0 || queued_lines > g_tail_lines) {
 320                     chooseFirst(devices, &dev);
 321                     if (dev == NULL || dev->queue->next == NULL) {
 322                         break;
 323                     }
 324                     if (g_tail_lines == 0) {
 325                         printNextEntry(dev);
 326                     } else {
 327                         skipNextEntry(dev);
 328                     }
 329                     --queued_lines;
 330                 }
 331             }
 332         }
 333 next:
 334         ;
 335     }
 336 }
 337
 338
 339 static int clear_log(int logfd)
 340 {
 341     return ioctl(logfd, LOGGER_FLUSH_LOG);
 342 }
 343
 344 /* returns the total size of the log's ring buffer */
 345 static int get_log_size(int logfd)
 346 {
 347     return ioctl(logfd, LOGGER_GET_LOG_BUF_SIZE);
 348 }
 349
 350 /* returns the readable size of the log's ring buffer (that is, amount of the log consumed) */
 351 static int get_log_readable_size(int logfd)
 352 {
 353     return ioctl(logfd, LOGGER_GET_LOG_LEN);
 354 }
 355
 356 static void setup_output()
 357 {
 358
 359     if (g_output_filename == NULL) {
 360         g_outfd = STDOUT_FILENO;
 361
 362     } else {
 363         struct stat statbuf;
 364
 365         g_outfd = open_logfile (g_output_filename);
 366
 367         if (g_outfd < 0) {
 368             perror ("couldn't open output file");
 369             exit(-1);
 370         }
 371
 372         fstat(g_outfd, &statbuf);
 373
 374         g_out_byte_count = statbuf.st_size;
 375     }
 376 }
 377
 378 static int set_log_format(const char * formatString)
 379 {
 380         static log_print_format format;
 381
 382         format = log_format_from_string(formatString);
 383
 384         if (format == FORMAT_OFF) {
 385                 // FORMAT_OFF means invalid string
 386                 return -1;
 387         }
 388
 389         log_set_print_format(g_logformat, format);
 390
 391         return 0;
 392 }
 393
 394 static void show_help(const char *cmd)
 395 {
 396     fprintf(stderr,"Usage: %s [options] [filterspecs]\n", cmd);
 397
 398     fprintf(stderr, "options include:\n"
 399                     "  -s              Set default filter to silent.\n"
 400                     "                  Like specifying filterspec '*:s'\n"
 401                     "  -f <filename>   Log to file. Default to stdout\n"
 402                     "  -r [<kbytes>]   Rotate log every kbytes. (16 if unspecified). Requires -f\n"
 403                     "  -n <count>      Sets max number of rotated logs to <count>, default 4\n"
 404                     "  -v <format>     Sets the log print format, where <format> is one of:\n\n"
 405                     "                  brief process tag thread raw time threadtime long\n\n"
 406                     "  -c              clear (flush) the entire log and exit\n"
 407                     "  -d              dump the log and then exit (don't block)\n"
 408                     "  -t <count>      print only the most recent <count> lines (implies -d)\n"
 409                     "  -g              get the size of the log's ring buffer and exit\n"
 410                     "  -b <buffer>     request alternate ring buffer\n"
 411                     "                  ('main' (default), 'radio', 'system')");
 412
 413
 414     fprintf(stderr,"\nfilterspecs are a series of \n"
 415                    "  <tag>[:priority]\n\n"
 416                    "where <tag> is a log component tag (or * for all) and priority is:\n"
 417                    "  V    Verbose\n"
 418                    "  D    Debug\n"
 419                    "  I    Info\n"
 420                    "  W    Warn\n"
 421                    "  E    Error\n"
 422                    "  F    Fatal\n"
 423                    "  S    Silent (supress all output)\n"
 424                    "\n'*' means '*:D' and <tag> by itself means <tag>:V\n"
 425                    "If no filterspec is found, filter defaults to '*:I'\n"
 426                    "\nIf not specified with -v, format is set defaults to \"brief\"\n\n");
 427
 428
 429
 430 }
 431
 432
 433 /*
 434  * free one log_device_t and it doesn't take care of chain so it
 435  * may break the chain list
 436  */
 437 static void log_devices_free(struct log_device_t *dev)
 438 {
 439         if (!dev)
 440                 return;
 441
 442         if (dev->device)
 443                 free(dev->device);
 444
 445         if (dev->queue) {
 446                 while (dev->queue->next) {
 447                         struct queued_entry_t *tmp = dev->queue->next;
 448                         dev->queue->next = tmp->next;
 449                         free(tmp);
 450                 }
 451                 free(dev->queue);
 452         }
 453
 454         free(dev);
 455         dev = NULL;
 456 }
 457
 458
 459 /*
 460  * free all the nodes after the "dev" and includes itself
 461  */
 462 static void log_devices_chain_free(struct log_device_t *dev)
 463 {
 464         if (!dev)
 465                 return;
 466
 467         while (dev->next) {
 468                 struct log_device_t *tmp = dev->next;
 469                 dev->next = tmp->next;
 470                 log_devices_free(tmp);
 471         }
 472
 473         log_devices_free(dev);
 474         dev = NULL;
 475 }
 476
 477
 478 /*
 479  * create a new log_device_t instance but don't care about
 480  * the device node accessable or not
 481  */
 482 static struct log_device_t *log_devices_new(const char *path)
 483 {
 484         struct log_device_t *new;
 485
 486         if (!path || strlen(path) <= 0)
 487                 return NULL;
 488
 489         new = malloc(sizeof(*new));
 490         if (!new) {
 491                 fprintf(stderr, "out of memory\n");
 492                 return NULL;
 493         }
 494
 495         new->device = strdup(path);
 496         new->fd = -1;
 497         new->printed = false;
 498         new->queue = NULL;
 499         new->next = NULL;
 500
 501         return new;
 502 }
 503
 504
 505 /*
 506  * add a new device to the tail of chain
 507  */
 508 static int log_devices_add_to_tail(struct log_device_t *devices, struct log_device_t *new)
 509 {
 510         struct log_device_t *tail = devices;
 511
 512         if (!devices || !new)
 513                 return -1;
 514
 515         while (tail->next)
 516                 tail = tail->next;
 517
 518         tail->next = new;
 519         g_dev_count++;
 520
 521         return 0;
 522 }
 523
 524 int main(int argc, char **argv)
 525 {
 526     int err;
 527     int has_set_log_format = 0;
 528     int is_clear_log = 0;
 529     int getLogSize = 0;
 530     int mode = O_RDONLY;
 531         int i;
 532 //    const char *forceFilters = NULL;
 533         struct log_device_t* devices = NULL;
 534         struct log_device_t* dev;
 535
 536     g_logformat = (log_format *)log_format_new();
 537
 538     if (argc == 2 && 0 == strcmp(argv[1], "--test")) {
 539         logprint_run_tests();
 540         exit(0);
 541     }
 542
 543     if (argc == 2 && 0 == strcmp(argv[1], "--help")) {
 544         show_help(argv[0]);
 545         exit(0);
 546     }
 547
 548     for (;;) {
 549         int ret;
 550
 551         ret = getopt(argc, argv, "cdt:gsf:r:n:v:b:D");
 552
 553         if (ret < 0) {
 554             break;
 555         }
 556
 557         switch(ret) {
 558             case 's':
 559                 // default to all silent
 560                 log_add_filter_rule(g_logformat, "*:s");
 561             break;
 562
 563             case 'c':
 564                 is_clear_log = 1;
 565                 mode = O_WRONLY;
 566             break;
 567
 568             case 'd':
 569                 g_nonblock = true;
 570             break;
 571
 572             case 't':
 573                 g_nonblock = true;
 574                 g_tail_lines = atoi(optarg);
 575             break;
 576
 577
 578             case 'g':
 579                 getLogSize = 1;
 580             break;
 581
 582                         case 'b': {
 583                                                   char *buf;
 584                                                   if (asprintf(&buf, LOG_FILE_DIR "/%s", optarg) == -1) {
 585                                                           asprintf(stderr,"Can't malloc LOG_FILE_DIR\n");
 586                                                           exit(-1);
 587                                                   }
 588
 589                                                   dev = log_devices_new(buf);
 590                 if (devices) {
 591                                         if (log_devices_add_to_tail(devices, dev)) {
 592                                                 fprintf(stderr, "Open log device %s failed\n", buf);
 593                                                 exit(-1);
 594                                         }
 595                 } else {
 596                                         devices = dev;
 597                                         g_dev_count = 1;
 598                 }
 599             }
 600             break;
 601
 602             case 'f':
 603                 // redirect output to a file
 604
 605                 g_output_filename = optarg;
 606
 607             break;
 608
 609             case 'r':
 610 //                if (optarg == NULL) {
 611 //                                      fprintf(stderr,"optarg == null\n");
 612  //                  g_log_rotate_size_kbytes = DEFAULT_LOG_ROTATE_SIZE_KBYTES;
 613  //              } else {
 614                     //long logRotateSize;
 615                     //char *lastDigit;
 616
 617                     if (!isdigit(optarg[0])) {
 618                         fprintf(stderr,"Invalid parameter to -r\n");
 619                         show_help(argv[0]);
 620                         exit(-1);
 621                     }
 622                     g_log_rotate_size_kbytes = atoi(optarg);
 623    //             }
 624             break;
 625
 626             case 'n':
 627                 if (!isdigit(optarg[0])) {
 628                     fprintf(stderr,"Invalid parameter to -r\n");
 629                     show_help(argv[0]);
 630                     exit(-1);
 631                 }
 632
 633                 g_max_rotated_logs = atoi(optarg);
 634             break;
 635
 636             case 'v':
 637                 err = set_log_format (optarg);
 638                 if (err < 0) {
 639                     fprintf(stderr,"Invalid parameter to -v\n");
 640                     show_help(argv[0]);
 641                     exit(-1);
 642                 }
 643
 644                 has_set_log_format = 1;
 645             break;
 646
 647                         default:
 648                                 fprintf(stderr,"Unrecognized Option\n");
 649                                 show_help(argv[0]);
 650                                 exit(-1);
 651                         break;
 652                 }
 653         }
 654
 655         if (!devices) {
 656                 devices = log_devices_new("/dev/"LOGGER_LOG_MAIN);
 657                 if (devices == NULL) {
 658                         fprintf(stderr,"Can't add log device: %s\n", LOGGER_LOG_MAIN);
 659                         exit(-1);
 660                 }
 661         g_dev_count = 1;
 662
 663         int accessmode =
 664                   (mode == O_RDONLY) ? R_OK : 0
 665                 | (mode == O_WRONLY) ? W_OK : 0;
 666
 667         // only add this if it's available
 668         if (0 == access("/dev/"LOGGER_LOG_SYSTEM, accessmode)) {
 669                 if (log_devices_add_to_tail(devices, log_devices_new("/dev/"LOGGER_LOG_SYSTEM))) {
 670                         fprintf(stderr,"Can't add log device: %s\n", LOGGER_LOG_SYSTEM);
 671                         exit(-1);
 672                 }
 673         }
 674
 675         if (0 == access("/dev/"LOGGER_LOG_APPS, accessmode)) {
 676                 if (log_devices_add_to_tail(devices, log_devices_new("/dev/"LOGGER_LOG_APPS))) {
 677                         fprintf(stderr,"Can't add log device: %s\n", LOGGER_LOG_APPS);
 678                         exit(-1);
 679                 }
 680         }
 681 /*
 682         // only add this if it's available
 683         int fd;
 684         if ((fd = open("/dev/"LOGGER_LOG_SYSTEM, mode)) != -1) {
 685                 devices->next = (struct log_device_t *)malloc( sizeof(struct log_device_t));
 686                 devices->next->device = strdup("/dev/"LOGGER_LOG_SYSTEM);
 687                 devices->next->fd = -1;
 688                 devices->next->printed = false;
 689                 devices->next->queue = NULL;
 690                 devices->next->next = NULL;
 691                 g_dev_count ++;
 692
 693                 close(fd);
 694         }
 695 */
 696     }
 697
 698     if (g_log_rotate_size_kbytes != 0 && g_output_filename == NULL)
 699         {
 700                 fprintf(stderr,"-r requires -f as well\n");
 701                 show_help(argv[0]);
 702                 exit(-1);
 703         }
 704
 705     setup_output();
 706
 707
 708         if (has_set_log_format == 0) {
 709                 err = set_log_format("brief");
 710         }
 711 /*
 712                 const char* logFormat = getenv("DLOG_PRINTF_LOG");
 713
 714                 if (logFormat != NULL) {
 715                         err = set_log_format("brief");
 716
 717                         if (err < 0) {
 718                                 fprintf(stderr, "invalid format in DLOG_PRINTF_LOG '%s'\n", logFormat);
 719                         }
 720                 }
 721         }
 722         if (forceFilters) {
 723                 err = log_add_filter_string(g_logformat, forceFilters);
 724                 if (err < 0) {
 725                         fprintf (stderr, "Invalid filter expression in -logcat option\n");
 726                         exit(0);
 727                 }
 728         } else if (argc == optind) {
 729         // Add from environment variable
 730                 char *env_tags_orig = getenv("DLOG_LOG_TAGS");
 731
 732                 if (env_tags_orig != NULL) {
 733                         err = log_add_filter_string(g_logformat, env_tags_orig);
 734
 735                         if (err < 0) {
 736                                 fprintf(stderr, "Invalid filter expression in DLOG_LOG_TAGS\n");
 737                                 show_help(argv[0]);
 738                                 exit(-1);
 739                         }
 740                 }
 741         } else {
 742         // Add from commandline
 743 */
 744         fprintf(stderr,"arc = %d, optind = %d ,Kb %d, rotate %d\n", argc, optind,g_log_rotate_size_kbytes,g_max_rotated_logs);
 745
 746         if(argc == optind )
 747         {
 748                 // Add from environment variable
 749         //char *env_tags_orig = getenv("DLOG_TAGS");
 750                 log_add_filter_string(g_logformat, "*:d");
 751         }
 752         else
 753         {
 754
 755                 for (i = optind ; i < argc ; i++) {
 756                         err = log_add_filter_string(g_logformat, argv[i]);
 757
 758                         if (err < 0) {
 759                                 fprintf (stderr, "Invalid filter expression '%s'\n", argv[i]);
 760                                 show_help(argv[0]);
 761                                 exit(-1);
 762                         }
 763                 }
 764         }
 765 /*
 766     }
 767 */
 768     dev = devices;
 769     while (dev) {
 770         dev->fd = open(dev->device, mode);
 771         if (dev->fd < 0) {
 772             fprintf(stderr, "Unable to open log device '%s': %s\n",
 773                 dev->device, strerror(errno));
 774             exit(EXIT_FAILURE);
 775         }
 776
 777         if (is_clear_log) {
 778             int ret;
 779             ret = clear_log(dev->fd);
 780             if (ret) {
 781                 perror("ioctl");
 782                 exit(EXIT_FAILURE);
 783             }
 784         }
 785
 786         if (getLogSize) {
 787             int size, readable;
 788
 789             size = get_log_size(dev->fd);
 790             if (size < 0) {
 791                 perror("ioctl");
 792                 exit(EXIT_FAILURE);
 793             }
 794
 795             readable = get_log_readable_size(dev->fd);
 796             if (readable < 0) {
 797                 perror("ioctl");
 798                 exit(EXIT_FAILURE);
 799             }
 800
 801             printf("%s: ring buffer is %dKb (%dKb consumed), "
 802                    "max entry is %db, max payload is %db\n", dev->device,
 803                    size / 1024, readable / 1024,
 804                    (int) LOGGER_ENTRY_MAX_LEN, (int) LOGGER_ENTRY_MAX_PAYLOAD);
 805         }
 806
 807         dev = dev->next;
 808     }
 809
 810     if (getLogSize) {
 811         return 0;
 812     }
 813
 814     if (is_clear_log) {
 815         return 0;
 816     }
 817
 818     read_log_lines(devices);
 819
 820         log_devices_chain_free(devices);
 821
 822     return 0;
 823 }