usr.sbin/gstat/gstat.c

   1 /*-
   2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
   3  *
   4  * Copyright (c) 2003 Poul-Henning Kamp
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. The names of the authors may not be used to endorse or promote
  16  *    products derived from this software without specific prior written
  17  *    permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  * $FreeBSD$
  32  */
  33
  34
  35 #include <sys/devicestat.h>
  36 #include <sys/mman.h>
  37 #include <sys/resource.h>
  38 #include <sys/time.h>
  39
  40 #include <curses.h>
  41 #include <devstat.h>
  42 #include <err.h>
  43 #include <errno.h>
  44 #include <fcntl.h>
  45 #include <histedit.h>
  46 #include <libgeom.h>
  47 #include <paths.h>
  48 #include <regex.h>
  49 #include <stdint.h>
  50 #include <stdio.h>
  51 #include <stdlib.h>
  52 #include <string.h>
  53 #include <sysexits.h>
  54 #include <unistd.h>
  55
  56 static int flag_a, flag_b, flag_B, flag_c, flag_C, flag_d, flag_o, flag_p,
  57            flag_s;
  58 static int flag_I = 1000000;
  59
  60 #define HIGH_PCT_BUSY_THRESH 80
  61 #define MEDIUM_PCT_BUSY_THRESH 50
  62 #define PRINTMSG(...) do {                                              \
  63                 if ((flag_b && !loop) || (flag_B))                      \
  64                         printf(__VA_ARGS__);                            \
  65                 else if (!flag_b)                                       \
  66                         printw(__VA_ARGS__);                            \
  67         } while(0)
  68
  69 static void usage(void);
  70
  71 static const char*
  72 el_prompt(void)
  73 {
  74
  75         return ("Filter: ");
  76 }
  77
  78 int
  79 main(int argc, char **argv)
  80 {
  81         int error, i, quit;
  82         int curx, cury, maxx, maxy, line_len, loop, max_flen, head_printed;
  83         struct devstat *gsp, *gsq;
  84         void *sp, *sq;
  85         double dt;
  86         struct timespec tp, tq;
  87         struct gmesh gmp;
  88         struct gprovider *pp;
  89         struct gconsumer *cp;
  90         struct gident *gid;
  91         regex_t f_re, tmp_f_re;
  92         short cf, cb;
  93         char *p;
  94         char f_s[100], pf_s[100], tmp_f_s[100];
  95         char ts[100], g_name[4096];
  96         const char *line;
  97         long double ld[16];
  98         uint64_t u64;
  99         EditLine *el;
 100         History *hist;
 101         HistEvent hist_ev;
 102
 103         hist = NULL;
 104         el = NULL;
 105         maxx = -1;
 106         curx = -1;
 107         loop = 1;
 108         /* Turn on batch mode if output is not tty. */
 109         if (!isatty(fileno(stdout)))
 110                 flag_b = 1;
 111
 112         f_s[0] = '\0';
 113         while ((i = getopt(argc, argv, "abBdcCf:I:ops")) != -1) {
 114                 switch (i) {
 115                 case 'a':
 116                         flag_a = 1;
 117                         break;
 118                 case 'b':
 119                         flag_b = 1;
 120                         break;
 121                 case 'B':
 122                         flag_B = 1;
 123                         flag_b = 1;
 124                         break;
 125                 case 'c':
 126                         flag_c = 1;
 127                         break;
 128                 case 'C':
 129                         flag_C = 1;
 130                         /* csv out implies repeating batch mode */
 131                         flag_b = 1;
 132                         flag_B = 1;
 133                         head_printed = 0;
 134                         break;
 135                 case 'd':
 136                         flag_d = 1;
 137                         break;
 138                 case 'f':
 139                         if (strlen(optarg) > sizeof(f_s) - 1)
 140                                 errx(EX_USAGE, "Filter string too long");
 141                         if (regcomp(&f_re, optarg, REG_EXTENDED) != 0)
 142                                 errx(EX_USAGE,
 143                                     "Invalid filter - see re_format(7)");
 144                         strlcpy(f_s, optarg, sizeof(f_s));
 145                         break;
 146                 case 'o':
 147                         flag_o = 1;
 148                         break;
 149                 case 'I':
 150                         p = NULL;
 151                         i = strtoul(optarg, &p, 0);
 152                         if (p == optarg || errno == EINVAL ||
 153                             errno == ERANGE) {
 154                                 errx(1, "Invalid argument to -I");
 155                         } else if (!strcmp(p, "s"))
 156                                 i *= 1000000;
 157                         else if (!strcmp(p, "ms"))
 158                                 i *= 1000;
 159                         else if (!strcmp(p, "us"))
 160                                 i *= 1;
 161                         flag_I = i;
 162                         break;
 163                 case 'p':
 164                         flag_p = 1;
 165                         break;
 166                 case 's':
 167                         flag_s = 1;
 168                         break;
 169                 case '?':
 170                 default:
 171                         usage();
 172                 }
 173         }
 174         argc -= optind;
 175         argv += optind;
 176         if (argc != 0)
 177                 usage();
 178
 179         i = geom_gettree(&gmp);
 180         if (i != 0)
 181                 err(1, "geom_gettree = %d", i);
 182         error = geom_stats_open();
 183         if (error)
 184                 err(1, "geom_stats_open()");
 185         sq = NULL;
 186         sq = geom_stats_snapshot_get();
 187         if (sq == NULL)
 188                 err(1, "geom_stats_snapshot()");
 189         if (!flag_b) {
 190                 /* Setup libedit */
 191                 hist = history_init();
 192                 if (hist == NULL)
 193                         err(EX_SOFTWARE, "history_init()");
 194                 history(hist, &hist_ev, H_SETSIZE, 100);
 195                 el = el_init("gstat", stdin, stdout, stderr);
 196                 if (el == NULL)
 197                         err(EX_SOFTWARE, "el_init");
 198                 el_set(el, EL_EDITOR, "emacs");
 199                 el_set(el, EL_SIGNAL, 1);
 200                 el_set(el, EL_HIST, history, hist);
 201                 el_set(el, EL_PROMPT, el_prompt);
 202                 if (f_s[0] != '\0')
 203                         history(hist, &hist_ev, H_ENTER, f_s);
 204                 /* Setup curses */
 205                 initscr();
 206                 start_color();
 207                 use_default_colors();
 208                 pair_content(0, &cf, &cb);
 209                 init_pair(1, COLOR_GREEN, cb);
 210                 init_pair(2, COLOR_MAGENTA, cb);
 211                 init_pair(3, COLOR_RED, cb);
 212                 cbreak();
 213                 noecho();
 214                 nonl();
 215                 nodelay(stdscr, 1);
 216                 intrflush(stdscr, FALSE);
 217                 keypad(stdscr, TRUE);
 218         }
 219         geom_stats_snapshot_timestamp(sq, &tq);
 220         for (quit = 0; !quit;) {
 221                 sp = geom_stats_snapshot_get();
 222                 if (sp == NULL)
 223                         err(1, "geom_stats_snapshot()");
 224                 geom_stats_snapshot_timestamp(sp, &tp);
 225                 dt = tp.tv_sec - tq.tv_sec;
 226                 dt += (tp.tv_nsec - tq.tv_nsec) * 1e-9;
 227                 tq = tp;
 228                 if (flag_C) { /* set timestamp string */
 229                         (void)strftime(ts,sizeof(ts),
 230                                         "%F %T",localtime(&tq.tv_sec));
 231                         (void)snprintf(ts,sizeof(ts),
 232                                         "%s.%.9ld",ts,tq.tv_nsec);
 233                 }
 234
 235                 geom_stats_snapshot_reset(sp);
 236                 geom_stats_snapshot_reset(sq);
 237                 if (!flag_b)
 238                         move(0,0);
 239                 if (!flag_C)
 240                         PRINTMSG("dT: %5.3fs  w: %.3fs", dt,
 241                                         (float)flag_I / 1000000);
 242                 if (!flag_C && f_s[0] != '\0') {
 243                         PRINTMSG("  filter: ");
 244                         if (!flag_b) {
 245                                 getyx(stdscr, cury, curx);
 246                                 getmaxyx(stdscr, maxy, maxx);
 247                         }
 248                         strlcpy(pf_s, f_s, sizeof(pf_s));
 249                         max_flen = maxx - curx - 1;
 250                         if ((int)strlen(f_s) > max_flen && max_flen >= 0) {
 251                                 if (max_flen > 3)
 252                                         pf_s[max_flen - 3] = '.';
 253                                 if (max_flen > 2)
 254                                         pf_s[max_flen - 2] = '.';
 255                                 if (max_flen > 1)
 256                                         pf_s[max_flen - 1] = '.';
 257                                 pf_s[max_flen] = '\0';
 258                         }
 259                         PRINTMSG("%s", pf_s);
 260                 }
 261                 if (!flag_C) {
 262                         PRINTMSG("\n");
 263                         PRINTMSG(" L(q)  ops/s   ");
 264                         if (flag_s) {
 265                                 PRINTMSG(" r/s     kB   kBps   ms/r   ");
 266                                 PRINTMSG(" w/s     kB   kBps   ms/w   ");
 267                         }
 268                         else {
 269                                 PRINTMSG(" r/s   kBps   ms/r   ");
 270                                 PRINTMSG(" w/s   kBps   ms/w   ");
 271                         }
 272                         if (flag_d) {
 273                                 if (flag_s) {
 274                                         PRINTMSG(" d/s     kB   kBps");
 275                                         PRINTMSG("   ms/d   ");
 276                                 } else
 277                                         PRINTMSG(" d/s   kBps   ms/d   ");
 278                         }
 279                         if (flag_o)
 280                                 PRINTMSG(" o/s   ms/o   ");
 281                         PRINTMSG("%%busy Name\n");
 282                 } else if (flag_C && !head_printed) {
 283                         PRINTMSG("timestamp,name,q-depth,total_ops/s");
 284                         if (flag_s) {
 285                                 PRINTMSG(",read/s,read_sz-KiB");
 286                                 PRINTMSG(",read-KiB/s,ms/read");
 287                                 PRINTMSG(",write/s,write_sz-KiB");
 288                                 PRINTMSG(",write-KiB/s,ms/write");
 289                         } else {
 290                                 PRINTMSG(",read/s,read-KiB/s,ms/read");
 291                                 PRINTMSG(",write/s,write-KiB/s,ms/write");
 292                         }
 293                         if (flag_d) {
 294                                 if (flag_s) {
 295                                         PRINTMSG(",delete/s,delete-sz-KiB");
 296                                         PRINTMSG(",delete-KiB/s,ms/delete");
 297                                 } else {
 298                                         PRINTMSG(",delete/s,delete-KiB/s");
 299                                         PRINTMSG(",ms/delete");
 300                                 }
 301                         }
 302                         if (flag_o)
 303                                 PRINTMSG(",other/s,ms/other");
 304                         PRINTMSG(",%%busy\n");
 305                         head_printed = 1;
 306                 }
 307                 for (;;) {
 308                         gsp = geom_stats_snapshot_next(sp);
 309                         gsq = geom_stats_snapshot_next(sq);
 310                         if (gsp == NULL || gsq == NULL)
 311                                 break;
 312                         if (gsp->id == NULL)
 313                                 continue;
 314                         gid = geom_lookupid(&gmp, gsp->id);
 315                         if (gid == NULL) {
 316                                 geom_deletetree(&gmp);
 317                                 i = geom_gettree(&gmp);
 318                                 if (i != 0)
 319                                         err(1, "geom_gettree = %d", i);
 320                                 gid = geom_lookupid(&gmp, gsp->id);
 321                         }
 322                         if (gid == NULL)
 323                                 continue;
 324                         if (gid->lg_what == ISCONSUMER && !flag_c)
 325                                 continue;
 326                         if (flag_p && gid->lg_what == ISPROVIDER &&
 327                            ((struct gprovider *)
 328                             (gid->lg_ptr))->lg_geom->lg_rank != 1)
 329                                 continue;
 330                         /* Do not print past end of window */
 331                         if (!flag_b) {
 332                                 getyx(stdscr, cury, curx);
 333                                 if (curx > 0)
 334                                         continue;
 335                         }
 336                         if ((gid->lg_what == ISPROVIDER
 337                             || gid->lg_what == ISCONSUMER) && f_s[0] != '\0') {
 338                                 pp = gid->lg_ptr;
 339                                 if ((regexec(&f_re, pp->lg_name, 0, NULL, 0)
 340                                      != 0))
 341                                   continue;
 342                         }
 343                         if (gsp->sequence0 != gsp->sequence1) {
 344                                 /*
 345                                  * it is ok to skip entire line silently
 346                                  * for CSV output
 347                                  */
 348                                 if (!flag_C)
 349                                         PRINTMSG("*\n");
 350                                 continue;
 351                         }
 352                         devstat_compute_statistics(gsp, gsq, dt,
 353                             DSM_QUEUE_LENGTH, &u64,
 354                             DSM_TRANSFERS_PER_SECOND, &ld[0],
 355
 356                             DSM_TRANSFERS_PER_SECOND_READ, &ld[1],
 357                             DSM_MB_PER_SECOND_READ, &ld[2],
 358                             DSM_MS_PER_TRANSACTION_READ, &ld[3],
 359
 360                             DSM_TRANSFERS_PER_SECOND_WRITE, &ld[4],
 361                             DSM_MB_PER_SECOND_WRITE, &ld[5],
 362                             DSM_MS_PER_TRANSACTION_WRITE, &ld[6],
 363
 364                             DSM_BUSY_PCT, &ld[7],
 365
 366                             DSM_TRANSFERS_PER_SECOND_FREE, &ld[8],
 367                             DSM_MB_PER_SECOND_FREE, &ld[9],
 368                             DSM_MS_PER_TRANSACTION_FREE, &ld[10],
 369
 370                             DSM_TRANSFERS_PER_SECOND_OTHER, &ld[11],
 371                             DSM_MS_PER_TRANSACTION_OTHER, &ld[12],
 372
 373                             DSM_KB_PER_TRANSFER_READ, &ld[13],
 374                             DSM_KB_PER_TRANSFER_WRITE, &ld[14],
 375                             DSM_KB_PER_TRANSFER_FREE, &ld[15],
 376
 377                             DSM_NONE);
 378
 379                         if (flag_a && ld[7] < 0.1) {
 380                                 *gsq = *gsp;
 381                                 continue;
 382                         }
 383
 384                         /* store name for geom device */
 385                         if (gid == NULL) {
 386                                 (void)snprintf(g_name, sizeof(g_name), "??");
 387                         } else if (gid->lg_what == ISPROVIDER) {
 388                                 pp = gid->lg_ptr;
 389                                 (void)snprintf(g_name, sizeof(g_name), "%s",
 390                                                 pp->lg_name);
 391                         } else if (gid->lg_what == ISCONSUMER) {
 392                                 cp = gid->lg_ptr;
 393                                 (void)snprintf(g_name, sizeof(g_name),
 394                                         "%s/%s/%s",
 395                                         cp->lg_geom->lg_class->lg_name,
 396                                         cp->lg_geom->lg_name,
 397                                         cp->lg_provider->lg_name);
 398                         }
 399
 400                         if (flag_C) {
 401                                 PRINTMSG("%s", ts); /* timestamp */
 402                                 PRINTMSG(",%s", g_name); /* print name */
 403                                 PRINTMSG(",%ju", (uintmax_t)u64);
 404                                 PRINTMSG(",%.0f", (double)ld[0]);
 405                                 PRINTMSG(",%.0f", (double)ld[1]);
 406                                 if (flag_s)
 407                                         PRINTMSG(",%.0f", (double)ld[13]);
 408                                 PRINTMSG(",%.0f", (double)ld[2] * 1024);
 409                                 if (ld[3] > 1e3)
 410                                         PRINTMSG(",%.0f", (double)ld[3]);
 411                                 else
 412                                         PRINTMSG(",%.1f", (double)ld[3]);
 413                                 PRINTMSG(",%.0f", (double)ld[4]);
 414                                 if (flag_s)
 415                                         PRINTMSG(",%.0f", (double)ld[14]);
 416                                 PRINTMSG(",%.0f", (double)ld[5] * 1024);
 417                                 if (ld[6] > 1e3)
 418                                         PRINTMSG(",%.0f", (double)ld[6]);
 419                                 else
 420                                         PRINTMSG(",%.1f", (double)ld[6]);
 421
 422                                 if (flag_d) {
 423                                         PRINTMSG(",%.0f", (double)ld[8]);
 424                                         if (flag_s)
 425                                                 PRINTMSG(",%.0f",
 426                                                                 (double)ld[15]);
 427                                         PRINTMSG(",%.0f", (double)ld[9] * 1024);
 428                                         if (ld[10] > 1e3)
 429                                                 PRINTMSG(",%.0f",
 430                                                                 (double)ld[10]);
 431                                         else
 432                                                 PRINTMSG(",%.1f",
 433                                                                 (double)ld[10]);
 434                                 }
 435
 436                                 if (flag_o) {
 437                                         PRINTMSG(",%.0f", (double)ld[11]);
 438                                         if (ld[12] > 1e3)
 439                                                 PRINTMSG(",%.0f",
 440                                                                 (double)ld[12]);
 441                                         else
 442                                                 PRINTMSG(",%.1f",
 443                                                                 (double)ld[12]);
 444                                 }
 445                                 PRINTMSG(",%.1lf", (double)ld[7]);
 446                         } else {
 447                                 PRINTMSG(" %4ju", (uintmax_t)u64);
 448                                 PRINTMSG(" %6.0f", (double)ld[0]);
 449                                 PRINTMSG(" %6.0f", (double)ld[1]);
 450                                 if (flag_s)
 451                                         PRINTMSG(" %6.0f", (double)ld[13]);
 452                                 PRINTMSG(" %6.0f", (double)ld[2] * 1024);
 453                                 if (ld[3] > 1e3)
 454                                         PRINTMSG(" %6.0f", (double)ld[3]);
 455                                 else
 456                                         PRINTMSG(" %6.1f", (double)ld[3]);
 457                                 PRINTMSG(" %6.0f", (double)ld[4]);
 458                                 if (flag_s)
 459                                         PRINTMSG(" %6.0f", (double)ld[14]);
 460                                 PRINTMSG(" %6.0f", (double)ld[5] * 1024);
 461                                 if (ld[6] > 1e3)
 462                                         PRINTMSG(" %6.0f", (double)ld[6]);
 463                                 else
 464                                         PRINTMSG(" %6.1f", (double)ld[6]);
 465
 466                                 if (flag_d) {
 467                                         PRINTMSG(" %6.0f", (double)ld[8]);
 468                                         if (flag_s)
 469                                                 PRINTMSG(" %6.0f",
 470                                                                 (double)ld[15]);
 471                                         PRINTMSG(" %6.0f",
 472                                                         (double)ld[9] * 1024);
 473                                         if (ld[10] > 1e3)
 474                                                 PRINTMSG(" %6.0f",
 475                                                                 (double)ld[10]);
 476                                         else
 477                                                 PRINTMSG(" %6.1f",
 478                                                                 (double)ld[10]);
 479                                 }
 480
 481                                 if (flag_o) {
 482                                         PRINTMSG(" %6.0f", (double)ld[11]);
 483                                         if (ld[12] > 1e3)
 484                                                 PRINTMSG(" %6.0f",
 485                                                                 (double)ld[12]);
 486                                         else
 487                                                 PRINTMSG(" %6.1f",
 488                                                                 (double)ld[12]);
 489                                 }
 490
 491                                 if (ld[7] > HIGH_PCT_BUSY_THRESH)
 492                                         i = 3;
 493                                 else if (ld[7] > MEDIUM_PCT_BUSY_THRESH)
 494                                         i = 2;
 495                                 else
 496                                         i = 1;
 497                                 if (!flag_b)
 498                                         attron(COLOR_PAIR(i));
 499                                 PRINTMSG(" %6.1lf", (double)ld[7]);
 500                                 if (!flag_b) {
 501                                         attroff(COLOR_PAIR(i));
 502                                         PRINTMSG("|");
 503                                 } else
 504                                         PRINTMSG(" ");
 505                                 PRINTMSG(" %s", g_name);
 506                                 if (!flag_b)
 507                                         clrtoeol();
 508                         }
 509                         PRINTMSG("\n");
 510                         *gsq = *gsp;
 511                 }
 512                 geom_stats_snapshot_free(sp);
 513                 if (flag_b) {
 514                         /* We loop extra to make sure we get the information. */
 515                         if (!loop)
 516                                 break;
 517                         if (!flag_B)
 518                                 loop = 0;
 519                         else
 520                                 if (fflush(stdout) == EOF)
 521                                         goto out;
 522                         usleep(flag_I);
 523                         continue;
 524                 }
 525                 getyx(stdscr, cury, curx);
 526                 getmaxyx(stdscr, maxy, maxx);
 527                 clrtobot();
 528                 if (maxy - 1 <= cury)
 529                         move(maxy - 1, 0);
 530                 refresh();
 531                 usleep(flag_I);
 532                 while((i = getch()) != ERR) {
 533                         switch (i) {
 534                         case '>':
 535                                 flag_I *= 2;
 536                                 break;
 537                         case '<':
 538                                 flag_I /= 2;
 539                                 if (flag_I < 1000)
 540                                         flag_I = 1000;
 541                                 break;
 542                         case 'c':
 543                                 flag_c = !flag_c;
 544                                 break;
 545                         case 'f':
 546                                 move(0,0);
 547                                 clrtoeol();
 548                                 refresh();
 549                                 line = el_gets(el, &line_len);
 550                                 if (line == NULL)
 551                                         err(1, "el_gets");
 552                                 if (line_len > 1)
 553                                         history(hist, &hist_ev, H_ENTER, line);
 554                                 strlcpy(tmp_f_s, line, sizeof(f_s));
 555                                 if ((p = strchr(tmp_f_s, '\n')) != NULL)
 556                                         *p = '\0';
 557                                 /*
 558                                  * Fix the terminal.  We messed up
 559                                  * curses idea of the screen by using
 560                                  * libedit.
 561                                  */
 562                                 clear();
 563                                 refresh();
 564                                 cbreak();
 565                                 noecho();
 566                                 nonl();
 567                                 if (regcomp(&tmp_f_re, tmp_f_s, REG_EXTENDED)
 568                                     != 0) {
 569                                         move(0, 0);
 570                                         printw("Invalid filter");
 571                                         refresh();
 572                                         sleep(1);
 573                                 } else {
 574                                         strlcpy(f_s, tmp_f_s, sizeof(f_s));
 575                                         f_re = tmp_f_re;
 576                                 }
 577                                 break;
 578                         case 'F':
 579                                 f_s[0] = '\0';
 580                                 break;
 581                         case 'q':
 582                                 quit = 1;
 583                                 break;
 584                         default:
 585                                 break;
 586                         }
 587                 }
 588         }
 589 out:
 590         if (!flag_b) {
 591                 el_end(el);
 592                 endwin();
 593         }
 594         exit(EX_OK);
 595 }
 596
 597 static void
 598 usage(void)
 599 {
 600         fprintf(stderr, "usage: gstat [-abBcCdps] [-f filter] [-I interval]\n");
 601         exit(EX_USAGE);
 602         /* NOTREACHED */
 603 }