release/src/router/busybox/procps/nmeter.c

   1 /*
   2  * Licensed under GPLv2, see file LICENSE in this source tree.
   3  *
   4  * Based on nanotop.c from floppyfw project
   5  *
   6  * Contact me: vda.linux@googlemail.com
   7  */
   8
   9 //config:config NMETER
  10 //config:       bool "nmeter"
  11 //config:       default y
  12 //config:       help
  13 //config:         Prints selected system stats continuously, one line per update.
  14
  15 //applet:IF_NMETER(APPLET(nmeter, BB_DIR_USR_BIN, BB_SUID_DROP))
  16
  17 //kbuild:lib-$(CONFIG_NMETER) += nmeter.o
  18
  19 //usage:#define nmeter_trivial_usage
  20 //usage:       "[-d MSEC] FORMAT_STRING"
  21 //usage:#define nmeter_full_usage "\n\n"
  22 //usage:       "Monitor system in real time"
  23 //usage:     "\n"
  24 //usage:     "\n -d MSEC        Milliseconds between updates (default:1000)"
  25 //usage:     "\n"
  26 //usage:     "\nFormat specifiers:"
  27 //usage:     "\n %Nc or %[cN]   CPU. N - bar size (default:10)"
  28 //usage:     "\n                (displays: S:system U:user N:niced D:iowait I:irq i:softirq)"
  29 //usage:     "\n %[nINTERFACE]  Network INTERFACE"
  30 //usage:     "\n %m             Allocated memory"
  31 //usage:     "\n %[mf]          Free memory"
  32 //usage:     "\n %[mt]          Total memory"
  33 //usage:     "\n %s             Allocated swap"
  34 //usage:     "\n %f             Number of used file descriptors"
  35 //usage:     "\n %Ni            Total/specific IRQ rate"
  36 //usage:     "\n %x             Context switch rate"
  37 //usage:     "\n %p             Forks"
  38 //usage:     "\n %[pn]          # of processes"
  39 //usage:     "\n %b             Block io"
  40 //usage:     "\n %Nt            Time (with N decimal points)"
  41 //usage:     "\n %r             Print <cr> instead of <lf> at EOL"
  42
  43 //TODO:
  44 // simplify code
  45 // /proc/locks
  46 // /proc/stat:
  47 // disk_io: (3,0):(22272,17897,410702,4375,54750)
  48 // btime 1059401962
  49 //TODO: use sysinfo libc call/syscall, if appropriate
  50 // (faster than open/read/close):
  51 // sysinfo({uptime=15017, loads=[5728, 15040, 16480]
  52 //  totalram=2107416576, freeram=211525632, sharedram=0, bufferram=157204480}
  53 //  totalswap=134209536, freeswap=134209536, procs=157})
  54
  55 #include "libbb.h"
  56
  57 typedef unsigned long long ullong;
  58
  59 enum {  /* Preferably use powers of 2 */
  60         PROC_MIN_FILE_SIZE = 256,
  61         PROC_MAX_FILE_SIZE = 16 * 1024,
  62 };
  63
  64 typedef struct proc_file {
  65         char *file;
  66         int file_sz;
  67         smallint last_gen;
  68 } proc_file;
  69
  70 static const char *const proc_name[] = {
  71         "stat",         // Must match the order of proc_file's!
  72         "loadavg",
  73         "net/dev",
  74         "meminfo",
  75         "diskstats",
  76         "sys/fs/file-nr"
  77 };
  78
  79 struct globals {
  80         // Sample generation flip-flop
  81         smallint gen;
  82         // Linux 2.6? (otherwise assumes 2.4)
  83         smallint is26;
  84         // 1 if sample delay is not an integer fraction of a second
  85         smallint need_seconds;
  86         char *cur_outbuf;
  87         const char *final_str;
  88         int delta;
  89         int deltanz;
  90         struct timeval tv;
  91 #define first_proc_file proc_stat
  92         proc_file proc_stat;    // Must match the order of proc_name's!
  93         proc_file proc_loadavg;
  94         proc_file proc_net_dev;
  95         proc_file proc_meminfo;
  96         proc_file proc_diskstats;
  97         proc_file proc_sys_fs_filenr;
  98 };
  99 #define G (*ptr_to_globals)
 100 #define gen                (G.gen               )
 101 #define is26               (G.is26              )
 102 #define need_seconds       (G.need_seconds      )
 103 #define cur_outbuf         (G.cur_outbuf        )
 104 #define final_str          (G.final_str         )
 105 #define delta              (G.delta             )
 106 #define deltanz            (G.deltanz           )
 107 #define tv                 (G.tv                )
 108 #define proc_stat          (G.proc_stat         )
 109 #define proc_loadavg       (G.proc_loadavg      )
 110 #define proc_net_dev       (G.proc_net_dev      )
 111 #define proc_meminfo       (G.proc_meminfo      )
 112 #define proc_diskstats     (G.proc_diskstats    )
 113 #define proc_sys_fs_filenr (G.proc_sys_fs_filenr)
 114 #define INIT_G() do { \
 115         SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
 116         cur_outbuf = outbuf; \
 117         final_str = "\n"; \
 118         deltanz = delta = 1000000; \
 119 } while (0)
 120
 121 // We depend on this being a char[], not char* - we take sizeof() of it
 122 #define outbuf bb_common_bufsiz1
 123
 124 static inline void reset_outbuf(void)
 125 {
 126         cur_outbuf = outbuf;
 127 }
 128
 129 static inline int outbuf_count(void)
 130 {
 131         return cur_outbuf - outbuf;
 132 }
 133
 134 static void print_outbuf(void)
 135 {
 136         int sz = cur_outbuf - outbuf;
 137         if (sz > 0) {
 138                 xwrite(STDOUT_FILENO, outbuf, sz);
 139                 cur_outbuf = outbuf;
 140         }
 141 }
 142
 143 static void put(const char *s)
 144 {
 145         int sz = strlen(s);
 146         if (sz > outbuf + sizeof(outbuf) - cur_outbuf)
 147                 sz = outbuf + sizeof(outbuf) - cur_outbuf;
 148         memcpy(cur_outbuf, s, sz);
 149         cur_outbuf += sz;
 150 }
 151
 152 static void put_c(char c)
 153 {
 154         if (cur_outbuf < outbuf + sizeof(outbuf))
 155                 *cur_outbuf++ = c;
 156 }
 157
 158 static void put_question_marks(int count)
 159 {
 160         while (count--)
 161                 put_c('?');
 162 }
 163
 164 static void readfile_z(proc_file *pf, const char* fname)
 165 {
 166 // open_read_close() will do two reads in order to be sure we are at EOF,
 167 // and we don't need/want that.
 168         int fd;
 169         int sz, rdsz;
 170         char *buf;
 171
 172         sz = pf->file_sz;
 173         buf = pf->file;
 174         if (!buf) {
 175                 buf = xmalloc(PROC_MIN_FILE_SIZE);
 176                 sz = PROC_MIN_FILE_SIZE;
 177         }
 178  again:
 179         fd = xopen(fname, O_RDONLY);
 180         buf[0] = '\0';
 181         rdsz = read(fd, buf, sz-1);
 182         close(fd);
 183         if (rdsz > 0) {
 184                 if (rdsz == sz-1 && sz < PROC_MAX_FILE_SIZE) {
 185                         sz *= 2;
 186                         buf = xrealloc(buf, sz);
 187                         goto again;
 188                 }
 189                 buf[rdsz] = '\0';
 190         }
 191         pf->file_sz = sz;
 192         pf->file = buf;
 193 }
 194
 195 static const char* get_file(proc_file *pf)
 196 {
 197         if (pf->last_gen != gen) {
 198                 pf->last_gen = gen;
 199                 readfile_z(pf, proc_name[pf - &first_proc_file]);
 200         }
 201         return pf->file;
 202 }
 203
 204 static ullong read_after_slash(const char *p)
 205 {
 206         p = strchr(p, '/');
 207         if (!p) return 0;
 208         return strtoull(p+1, NULL, 10);
 209 }
 210
 211 enum conv_type { conv_decimal, conv_slash };
 212
 213 // Reads decimal values from line. Values start after key, for example:
 214 // "cpu  649369 0 341297 4336769..." - key is "cpu" here.
 215 // Values are stored in vec[]. arg_ptr has list of positions
 216 // we are interested in: for example: 1,2,5 - we want 1st, 2nd and 5th value.
 217 static int vrdval(const char* p, const char* key,
 218         enum conv_type conv, ullong *vec, va_list arg_ptr)
 219 {
 220         int indexline;
 221         int indexnext;
 222
 223         p = strstr(p, key);
 224         if (!p) return 1;
 225
 226         p += strlen(key);
 227         indexline = 1;
 228         indexnext = va_arg(arg_ptr, int);
 229         while (1) {
 230                 while (*p == ' ' || *p == '\t') p++;
 231                 if (*p == '\n' || *p == '\0') break;
 232
 233                 if (indexline == indexnext) { // read this value
 234                         *vec++ = conv==conv_decimal ?
 235                                 strtoull(p, NULL, 10) :
 236                                 read_after_slash(p);
 237                         indexnext = va_arg(arg_ptr, int);
 238                 }
 239                 while (*p > ' ') p++; // skip over value
 240                 indexline++;
 241         }
 242         return 0;
 243 }
 244
 245 // Parses files with lines like "cpu0 21727 0 15718 1813856 9461 10485 0 0":
 246 // rdval(file_contents, "string_to_find", result_vector, value#, value#...)
 247 // value# start with 1
 248 static int rdval(const char* p, const char* key, ullong *vec, ...)
 249 {
 250         va_list arg_ptr;
 251         int result;
 252
 253         va_start(arg_ptr, vec);
 254         result = vrdval(p, key, conv_decimal, vec, arg_ptr);
 255         va_end(arg_ptr);
 256
 257         return result;
 258 }
 259
 260 // Parses files with lines like "... ... ... 3/148 ...."
 261 static int rdval_loadavg(const char* p, ullong *vec, ...)
 262 {
 263         va_list arg_ptr;
 264         int result;
 265
 266         va_start(arg_ptr, vec);
 267         result = vrdval(p, "", conv_slash, vec, arg_ptr);
 268         va_end(arg_ptr);
 269
 270         return result;
 271 }
 272
 273 // Parses /proc/diskstats
 274 //   1  2 3   4     5     6(rd)  7      8     9     10(wr) 11     12 13     14
 275 //   3  0 hda 51292 14441 841783 926052 25717 79650 843256 3029804 0 148459 3956933
 276 //   3  1 hda1 0 0 0 0 <- ignore if only 4 fields
 277 // Linux 3.0 (maybe earlier) started printing full stats for hda1 too.
 278 // Had to add code which skips such devices.
 279 static int rdval_diskstats(const char* p, ullong *vec)
 280 {
 281         char devname[32];
 282         unsigned devname_len = 0;
 283         int value_idx = 0;
 284
 285         vec[0] = 0;
 286         vec[1] = 0;
 287         while (1) {
 288                 value_idx++;
 289                 while (*p == ' ' || *p == '\t')
 290                         p++;
 291                 if (*p == '\0')
 292                         break;
 293                 if (*p == '\n') {
 294                         value_idx = 0;
 295                         p++;
 296                         continue;
 297                 }
 298                 if (value_idx == 3) {
 299                         char *end = strchrnul(p, ' ');
 300                         /* If this a hda1-like device (same prefix as last one + digit)? */
 301                         if (devname_len && strncmp(devname, p, devname_len) == 0 && isdigit(p[devname_len])) {
 302                                 p = end;
 303                                 goto skip_line; /* skip entire line */
 304                         }
 305                         /* It is not. Remember the name for future checks */
 306                         devname_len = end - p;
 307                         if (devname_len > sizeof(devname)-1)
 308                                 devname_len = sizeof(devname)-1;
 309                         strncpy(devname, p, devname_len);
 310                         /* devname[devname_len] = '\0'; - not really needed */
 311                         p = end;
 312                 } else
 313                 if (value_idx == 6) {
 314                         // TODO: *sectorsize (don't know how to find out sectorsize)
 315                         vec[0] += strtoull(p, NULL, 10);
 316                 } else
 317                 if (value_idx == 10) {
 318                         // TODO: *sectorsize (don't know how to find out sectorsize)
 319                         vec[1] += strtoull(p, NULL, 10);
 320  skip_line:
 321                         while (*p != '\n' && *p != '\0')
 322                                 p++;
 323                         continue;
 324                 }
 325                 while ((unsigned char)(*p) > ' ') // skip over value
 326                         p++;
 327         }
 328         return 0;
 329 }
 330
 331 static void scale(ullong ul)
 332 {
 333         char buf[5];
 334
 335         /* see http://en.wikipedia.org/wiki/Tera */
 336         smart_ulltoa4(ul, buf, " kmgtpezy")[0] = '\0';
 337         put(buf);
 338 }
 339
 340
 341 #define S_STAT(a) \
 342 typedef struct a { \
 343         struct s_stat *next; \
 344         void (*collect)(struct a *s) FAST_FUNC; \
 345         const char *label;
 346 #define S_STAT_END(a) } a;
 347
 348 S_STAT(s_stat)
 349 S_STAT_END(s_stat)
 350
 351 static void FAST_FUNC collect_literal(s_stat *s UNUSED_PARAM)
 352 {
 353 }
 354
 355 static s_stat* init_literal(void)
 356 {
 357         s_stat *s = xzalloc(sizeof(*s));
 358         s->collect = collect_literal;
 359         return (s_stat*)s;
 360 }
 361
 362 static s_stat* init_delay(const char *param)
 363 {
 364         delta = strtoul(param, NULL, 0) * 1000; /* param can be "" */
 365         deltanz = delta > 0 ? delta : 1;
 366         need_seconds = (1000000%deltanz) != 0;
 367         return NULL;
 368 }
 369
 370 static s_stat* init_cr(const char *param UNUSED_PARAM)
 371 {
 372         final_str = "\r";
 373         return (s_stat*)0;
 374 }
 375
 376
 377 //     user nice system idle  iowait irq  softirq (last 3 only in 2.6)
 378 //cpu  649369 0 341297 4336769 11640 7122 1183
 379 //cpuN 649369 0 341297 4336769 11640 7122 1183
 380 enum { CPU_FIELDCNT = 7 };
 381 S_STAT(cpu_stat)
 382         ullong old[CPU_FIELDCNT];
 383         int bar_sz;
 384         char *bar;
 385 S_STAT_END(cpu_stat)
 386
 387
 388 static void FAST_FUNC collect_cpu(cpu_stat *s)
 389 {
 390         ullong data[CPU_FIELDCNT] = { 0, 0, 0, 0, 0, 0, 0 };
 391         unsigned frac[CPU_FIELDCNT] = { 0, 0, 0, 0, 0, 0, 0 };
 392         ullong all = 0;
 393         int norm_all = 0;
 394         int bar_sz = s->bar_sz;
 395         char *bar = s->bar;
 396         int i;
 397
 398         if (rdval(get_file(&proc_stat), "cpu ", data, 1, 2, 3, 4, 5, 6, 7)) {
 399                 put_question_marks(bar_sz);
 400                 return;
 401         }
 402
 403         for (i = 0; i < CPU_FIELDCNT; i++) {
 404                 ullong old = s->old[i];
 405                 if (data[i] < old) old = data[i];               //sanitize
 406                 s->old[i] = data[i];
 407                 all += (data[i] -= old);
 408         }
 409
 410         if (all) {
 411                 for (i = 0; i < CPU_FIELDCNT; i++) {
 412                         ullong t = bar_sz * data[i];
 413                         norm_all += data[i] = t / all;
 414                         frac[i] = t % all;
 415                 }
 416
 417                 while (norm_all < bar_sz) {
 418                         unsigned max = frac[0];
 419                         int pos = 0;
 420                         for (i = 1; i < CPU_FIELDCNT; i++) {
 421                                 if (frac[i] > max) max = frac[i], pos = i;
 422                         }
 423                         frac[pos] = 0;  //avoid bumping up same value twice
 424                         data[pos]++;
 425                         norm_all++;
 426                 }
 427
 428                 memset(bar, '.', bar_sz);
 429                 memset(bar, 'S', data[2]); bar += data[2]; //sys
 430                 memset(bar, 'U', data[0]); bar += data[0]; //usr
 431                 memset(bar, 'N', data[1]); bar += data[1]; //nice
 432                 memset(bar, 'D', data[4]); bar += data[4]; //iowait
 433                 memset(bar, 'I', data[5]); bar += data[5]; //irq
 434                 memset(bar, 'i', data[6]); bar += data[6]; //softirq
 435         } else {
 436                 memset(bar, '?', bar_sz);
 437         }
 438         put(s->bar);
 439 }
 440
 441
 442 static s_stat* init_cpu(const char *param)
 443 {
 444         int sz;
 445         cpu_stat *s = xzalloc(sizeof(*s));
 446         s->collect = collect_cpu;
 447         sz = strtoul(param, NULL, 0); /* param can be "" */
 448         if (sz < 10) sz = 10;
 449         if (sz > 1000) sz = 1000;
 450         s->bar = xzalloc(sz+1);
 451         /*s->bar[sz] = '\0'; - xzalloc did it */
 452         s->bar_sz = sz;
 453         return (s_stat*)s;
 454 }
 455
 456
 457 S_STAT(int_stat)
 458         ullong old;
 459         int no;
 460 S_STAT_END(int_stat)
 461
 462 static void FAST_FUNC collect_int(int_stat *s)
 463 {
 464         ullong data[1];
 465         ullong old;
 466
 467         if (rdval(get_file(&proc_stat), "intr", data, s->no)) {
 468                 put_question_marks(4);
 469                 return;
 470         }
 471
 472         old = s->old;
 473         if (data[0] < old) old = data[0];               //sanitize
 474         s->old = data[0];
 475         scale(data[0] - old);
 476 }
 477
 478 static s_stat* init_int(const char *param)
 479 {
 480         int_stat *s = xzalloc(sizeof(*s));
 481         s->collect = collect_int;
 482         if (param[0] == '\0') {
 483                 s->no = 1;
 484         } else {
 485                 int n = xatoi_positive(param);
 486                 s->no = n + 2;
 487         }
 488         return (s_stat*)s;
 489 }
 490
 491
 492 S_STAT(ctx_stat)
 493         ullong old;
 494 S_STAT_END(ctx_stat)
 495
 496 static void FAST_FUNC collect_ctx(ctx_stat *s)
 497 {
 498         ullong data[1];
 499         ullong old;
 500
 501         if (rdval(get_file(&proc_stat), "ctxt", data, 1)) {
 502                 put_question_marks(4);
 503                 return;
 504         }
 505
 506         old = s->old;
 507         if (data[0] < old) old = data[0];               //sanitize
 508         s->old = data[0];
 509         scale(data[0] - old);
 510 }
 511
 512 static s_stat* init_ctx(const char *param UNUSED_PARAM)
 513 {
 514         ctx_stat *s = xzalloc(sizeof(*s));
 515         s->collect = collect_ctx;
 516         return (s_stat*)s;
 517 }
 518
 519
 520 S_STAT(blk_stat)
 521         const char* lookfor;
 522         ullong old[2];
 523 S_STAT_END(blk_stat)
 524
 525 static void FAST_FUNC collect_blk(blk_stat *s)
 526 {
 527         ullong data[2];
 528         int i;
 529
 530         if (is26) {
 531                 i = rdval_diskstats(get_file(&proc_diskstats), data);
 532         } else {
 533                 i = rdval(get_file(&proc_stat), s->lookfor, data, 1, 2);
 534                 // Linux 2.4 reports bio in Kbytes, convert to sectors:
 535                 data[0] *= 2;
 536                 data[1] *= 2;
 537         }
 538         if (i) {
 539                 put_question_marks(9);
 540                 return;
 541         }
 542
 543         for (i=0; i<2; i++) {
 544                 ullong old = s->old[i];
 545                 if (data[i] < old) old = data[i];               //sanitize
 546                 s->old[i] = data[i];
 547                 data[i] -= old;
 548         }
 549         scale(data[0]*512); // TODO: *sectorsize
 550         put_c(' ');
 551         scale(data[1]*512);
 552 }
 553
 554 static s_stat* init_blk(const char *param UNUSED_PARAM)
 555 {
 556         blk_stat *s = xzalloc(sizeof(*s));
 557         s->collect = collect_blk;
 558         s->lookfor = "page";
 559         return (s_stat*)s;
 560 }
 561
 562
 563 S_STAT(fork_stat)
 564         ullong old;
 565 S_STAT_END(fork_stat)
 566
 567 static void FAST_FUNC collect_thread_nr(fork_stat *s UNUSED_PARAM)
 568 {
 569         ullong data[1];
 570
 571         if (rdval_loadavg(get_file(&proc_loadavg), data, 4)) {
 572                 put_question_marks(4);
 573                 return;
 574         }
 575         scale(data[0]);
 576 }
 577
 578 static void FAST_FUNC collect_fork(fork_stat *s)
 579 {
 580         ullong data[1];
 581         ullong old;
 582
 583         if (rdval(get_file(&proc_stat), "processes", data, 1)) {
 584                 put_question_marks(4);
 585                 return;
 586         }
 587
 588         old = s->old;
 589         if (data[0] < old) old = data[0];       //sanitize
 590         s->old = data[0];
 591         scale(data[0] - old);
 592 }
 593
 594 static s_stat* init_fork(const char *param)
 595 {
 596         fork_stat *s = xzalloc(sizeof(*s));
 597         if (*param == 'n') {
 598                 s->collect = collect_thread_nr;
 599         } else {
 600                 s->collect = collect_fork;
 601         }
 602         return (s_stat*)s;
 603 }
 604
 605
 606 S_STAT(if_stat)
 607         ullong old[4];
 608         const char *device;
 609         char *device_colon;
 610 S_STAT_END(if_stat)
 611
 612 static void FAST_FUNC collect_if(if_stat *s)
 613 {
 614         ullong data[4];
 615         int i;
 616
 617         if (rdval(get_file(&proc_net_dev), s->device_colon, data, 1, 3, 9, 11)) {
 618                 put_question_marks(10);
 619                 return;
 620         }
 621
 622         for (i=0; i<4; i++) {
 623                 ullong old = s->old[i];
 624                 if (data[i] < old) old = data[i];               //sanitize
 625                 s->old[i] = data[i];
 626                 data[i] -= old;
 627         }
 628         put_c(data[1] ? '*' : ' ');
 629         scale(data[0]);
 630         put_c(data[3] ? '*' : ' ');
 631         scale(data[2]);
 632 }
 633
 634 static s_stat* init_if(const char *device)
 635 {
 636         if_stat *s = xzalloc(sizeof(*s));
 637
 638         if (!device || !device[0])
 639                 bb_show_usage();
 640         s->collect = collect_if;
 641
 642         s->device = device;
 643         s->device_colon = xasprintf("%s:", device);
 644         return (s_stat*)s;
 645 }
 646
 647
 648 S_STAT(mem_stat)
 649         char opt;
 650 S_STAT_END(mem_stat)
 651
 652 // "Memory" value should not include any caches.
 653 // IOW: neither "ls -laR /" nor heavy read/write activity
 654 //      should affect it. We'd like to also include any
 655 //      long-term allocated kernel-side mem, but it is hard
 656 //      to figure out. For now, bufs, cached & slab are
 657 //      counted as "free" memory
 658 //2.6.16:
 659 //MemTotal:       773280 kB
 660 //MemFree:         25912 kB - genuinely free
 661 //Buffers:        320672 kB - cache
 662 //Cached:         146396 kB - cache
 663 //SwapCached:          0 kB
 664 //Active:         183064 kB
 665 //Inactive:       356892 kB
 666 //HighTotal:           0 kB
 667 //HighFree:            0 kB
 668 //LowTotal:       773280 kB
 669 //LowFree:         25912 kB
 670 //SwapTotal:      131064 kB
 671 //SwapFree:       131064 kB
 672 //Dirty:              48 kB
 673 //Writeback:           0 kB
 674 //Mapped:          96620 kB
 675 //Slab:           200668 kB - takes 7 Mb on my box fresh after boot,
 676 //                            but includes dentries and inodes
 677 //                            (== can take arbitrary amount of mem)
 678 //CommitLimit:    517704 kB
 679 //Committed_AS:   236776 kB
 680 //PageTables:       1248 kB
 681 //VmallocTotal:   516052 kB
 682 //VmallocUsed:      3852 kB
 683 //VmallocChunk:   512096 kB
 684 //HugePages_Total:     0
 685 //HugePages_Free:      0
 686 //Hugepagesize:     4096 kB
 687 static void FAST_FUNC collect_mem(mem_stat *s)
 688 {
 689         ullong m_total = 0;
 690         ullong m_free = 0;
 691         ullong m_bufs = 0;
 692         ullong m_cached = 0;
 693         ullong m_slab = 0;
 694
 695         if (rdval(get_file(&proc_meminfo), "MemTotal:", &m_total, 1)) {
 696                 put_question_marks(4);
 697                 return;
 698         }
 699         if (s->opt == 't') {
 700                 scale(m_total << 10);
 701                 return;
 702         }
 703
 704         if (rdval(proc_meminfo.file, "MemFree:", &m_free  , 1)
 705          || rdval(proc_meminfo.file, "Buffers:", &m_bufs  , 1)
 706          || rdval(proc_meminfo.file, "Cached:",  &m_cached, 1)
 707          || rdval(proc_meminfo.file, "Slab:",    &m_slab  , 1)
 708         ) {
 709                 put_question_marks(4);
 710                 return;
 711         }
 712
 713         m_free += m_bufs + m_cached + m_slab;
 714         switch (s->opt) {
 715         case 'f':
 716                 scale(m_free << 10); break;
 717         default:
 718                 scale((m_total - m_free) << 10); break;
 719         }
 720 }
 721
 722 static s_stat* init_mem(const char *param)
 723 {
 724         mem_stat *s = xzalloc(sizeof(*s));
 725         s->collect = collect_mem;
 726         s->opt = param[0];
 727         return (s_stat*)s;
 728 }
 729
 730
 731 S_STAT(swp_stat)
 732 S_STAT_END(swp_stat)
 733
 734 static void FAST_FUNC collect_swp(swp_stat *s UNUSED_PARAM)
 735 {
 736         ullong s_total[1];
 737         ullong s_free[1];
 738         if (rdval(get_file(&proc_meminfo), "SwapTotal:", s_total, 1)
 739          || rdval(proc_meminfo.file,       "SwapFree:" , s_free,  1)
 740         ) {
 741                 put_question_marks(4);
 742                 return;
 743         }
 744         scale((s_total[0]-s_free[0]) << 10);
 745 }
 746
 747 static s_stat* init_swp(const char *param UNUSED_PARAM)
 748 {
 749         swp_stat *s = xzalloc(sizeof(*s));
 750         s->collect = collect_swp;
 751         return (s_stat*)s;
 752 }
 753
 754
 755 S_STAT(fd_stat)
 756 S_STAT_END(fd_stat)
 757
 758 static void FAST_FUNC collect_fd(fd_stat *s UNUSED_PARAM)
 759 {
 760         ullong data[2];
 761
 762         if (rdval(get_file(&proc_sys_fs_filenr), "", data, 1, 2)) {
 763                 put_question_marks(4);
 764                 return;
 765         }
 766
 767         scale(data[0] - data[1]);
 768 }
 769
 770 static s_stat* init_fd(const char *param UNUSED_PARAM)
 771 {
 772         fd_stat *s = xzalloc(sizeof(*s));
 773         s->collect = collect_fd;
 774         return (s_stat*)s;
 775 }
 776
 777
 778 S_STAT(time_stat)
 779         int prec;
 780         int scale;
 781 S_STAT_END(time_stat)
 782
 783 static void FAST_FUNC collect_time(time_stat *s)
 784 {
 785         char buf[sizeof("12:34:56.123456")];
 786         struct tm* tm;
 787         int us = tv.tv_usec + s->scale/2;
 788         time_t t = tv.tv_sec;
 789
 790         if (us >= 1000000) {
 791                 t++;
 792                 us -= 1000000;
 793         }
 794         tm = localtime(&t);
 795
 796         sprintf(buf, "%02d:%02d:%02d", tm->tm_hour, tm->tm_min, tm->tm_sec);
 797         if (s->prec)
 798                 sprintf(buf+8, ".%0*d", s->prec, us / s->scale);
 799         put(buf);
 800 }
 801
 802 static s_stat* init_time(const char *param)
 803 {
 804         int prec;
 805         time_stat *s = xzalloc(sizeof(*s));
 806
 807         s->collect = collect_time;
 808         prec = param[0] - '0';
 809         if (prec < 0) prec = 0;
 810         else if (prec > 6) prec = 6;
 811         s->prec = prec;
 812         s->scale = 1;
 813         while (prec++ < 6)
 814                 s->scale *= 10;
 815         return (s_stat*)s;
 816 }
 817
 818 static void FAST_FUNC collect_info(s_stat *s)
 819 {
 820         gen ^= 1;
 821         while (s) {
 822                 put(s->label);
 823                 s->collect(s);
 824                 s = s->next;
 825         }
 826 }
 827
 828
 829 typedef s_stat* init_func(const char *param);
 830
 831 // Deprecated %NNNd is to be removed, -d MSEC supersedes it
 832 static const char options[] ALIGN1 = "ncmsfixptbdr";
 833 static init_func *const init_functions[] = {
 834         init_if,
 835         init_cpu,
 836         init_mem,
 837         init_swp,
 838         init_fd,
 839         init_int,
 840         init_ctx,
 841         init_fork,
 842         init_time,
 843         init_blk,
 844         init_delay,
 845         init_cr
 846 };
 847
 848 int nmeter_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 849 int nmeter_main(int argc UNUSED_PARAM, char **argv)
 850 {
 851         char buf[32];
 852         s_stat *first = NULL;
 853         s_stat *last = NULL;
 854         s_stat *s;
 855         char *opt_d;
 856         char *cur, *prev;
 857
 858         INIT_G();
 859
 860         xchdir("/proc");
 861
 862         if (open_read_close("version", buf, sizeof(buf)-1) > 0) {
 863                 buf[sizeof(buf)-1] = '\0';
 864                 is26 = (strstr(buf, " 2.4.") == NULL);
 865         }
 866
 867         if (getopt32(argv, "d:", &opt_d))
 868                 init_delay(opt_d);
 869         argv += optind;
 870
 871         if (!argv[0])
 872                 bb_show_usage();
 873
 874         // Can use argv[0] directly, but this will mess up
 875         // parameters as seen by e.g. ps. Making a copy...
 876         cur = xstrdup(argv[0]);
 877         while (1) {
 878                 char *param, *p;
 879                 prev = cur;
 880  again:
 881                 cur = strchr(cur, '%');
 882                 if (!cur)
 883                         break;
 884                 if (cur[1] == '%') {    // %%
 885                         overlapping_strcpy(cur, cur + 1);
 886                         cur++;
 887                         goto again;
 888                 }
 889                 *cur++ = '\0';          // overwrite %
 890                 if (cur[0] == '[') {
 891                         // format: %[foptstring]
 892                         cur++;
 893                         p = strchr(options, cur[0]);
 894                         param = cur+1;
 895                         while (cur[0] != ']') {
 896                                 if (!cur[0])
 897                                         bb_show_usage();
 898                                 cur++;
 899                         }
 900                         *cur++ = '\0';  // overwrite [
 901                 } else {
 902                         // format: %NNNNNNf
 903                         param = cur;
 904                         while (cur[0] >= '0' && cur[0] <= '9')
 905                                 cur++;
 906                         if (!cur[0])
 907                                 bb_show_usage();
 908                         p = strchr(options, cur[0]);
 909                         *cur++ = '\0';  // overwrite format char
 910                 }
 911                 if (!p)
 912                         bb_show_usage();
 913                 s = init_functions[p-options](param);
 914                 if (s) {
 915                         s->label = prev;
 916                         /*s->next = NULL; - all initXXX funcs use xzalloc */
 917                         if (!first)
 918                                 first = s;
 919                         else
 920                                 last->next = s;
 921                         last = s;
 922                 } else {
 923                         // %NNNNd or %r option. remove it from string
 924                         strcpy(prev + strlen(prev), cur);
 925                         cur = prev;
 926                 }
 927         }
 928         if (prev[0]) {
 929                 s = init_literal();
 930                 s->label = prev;
 931                 /*s->next = NULL; - all initXXX funcs use xzalloc */
 932                 if (!first)
 933                         first = s;
 934                 else
 935                         last->next = s;
 936                 last = s;
 937         }
 938
 939         // Generate first samples but do not print them, they're bogus
 940         collect_info(first);
 941         reset_outbuf();
 942         if (delta >= 0) {
 943                 gettimeofday(&tv, NULL);
 944                 usleep(delta > 1000000 ? 1000000 : delta - tv.tv_usec%deltanz);
 945         }
 946
 947         while (1) {
 948                 gettimeofday(&tv, NULL);
 949                 collect_info(first);
 950                 put(final_str);
 951                 print_outbuf();
 952
 953                 // Negative delta -> no usleep at all
 954                 // This will hog the CPU but you can have REALLY GOOD
 955                 // time resolution ;)
 956                 // TODO: detect and avoid useless updates
 957                 // (like: nothing happens except time)
 958                 if (delta >= 0) {
 959                         int rem;
 960                         // can be commented out, will sacrifice sleep time precision a bit
 961                         gettimeofday(&tv, NULL);
 962                         if (need_seconds)
 963                                 rem = delta - ((ullong)tv.tv_sec*1000000 + tv.tv_usec) % deltanz;
 964                         else
 965                                 rem = delta - tv.tv_usec%deltanz;
 966                         // Sometimes kernel wakes us up just a tiny bit earlier than asked
 967                         // Do not go to very short sleep in this case
 968                         if (rem < delta/128) {
 969                                 rem += delta;
 970                         }
 971                         usleep(rem);
 972                 }
 973         }
 974
 975         /*return 0;*/
 976 }