external/bsd/top/dist/top.c

   1 /*
   2  * Copyright (c) 1984 through 2008, William LeFebvre
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are met:
   7  *
   8  *     * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *
  11  *     * Redistributions in binary form must reproduce the above
  12  * copyright notice, this list of conditions and the following disclaimer
  13  * in the documentation and/or other materials provided with the
  14  * distribution.
  15  *
  16  *     * Neither the name of William LeFebvre nor the names of other
  17  * contributors may be used to endorse or promote products derived from
  18  * this software without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  21  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  22  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  23  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  24  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  25  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  26  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  27  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  28  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  29  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  30  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  31  */
  32
  33 const char *copyright =
  34     "Copyright (c) 1984 through 2008, William LeFebvre";
  35
  36 /*
  37  * Changes to other files that we can do at the same time:
  38  * screen.c:init_termcap: get rid of the "interactive" argument and have it
  39  *      pass back something meaningful (such as success/failure/error).
  40  */
  41
  42 #include "os.h"
  43 #include <signal.h>
  44 #include <setjmp.h>
  45 #include <ctype.h>
  46 #include <sys/types.h>
  47 #include <sys/uio.h>
  48 #include <unistd.h>
  49
  50 #ifdef HAVE_SYS_UTSNAME_H
  51 #include <sys/utsname.h>
  52 #endif
  53
  54 #ifdef HAVE_GETOPT_H
  55 #include <getopt.h>
  56 #endif
  57
  58 /* definitions */
  59 #ifndef STDIN_FILENO
  60 #define STDIN_FILENO 0
  61 #endif
  62
  63 /* determine which type of signal functions to use */
  64 /* cant have sigaction without sigprocmask */
  65 #if defined(HAVE_SIGACTION) && !defined(HAVE_SIGPROCMASK)
  66 #undef HAVE_SIGACTION
  67 #endif
  68 /* always use sigaction when it is available */
  69 #ifdef HAVE_SIGACTION
  70 #undef HAVE_SIGHOLD
  71 #else
  72 /* use sighold/sigrelse, otherwise use old fashioned BSD signals */
  73 #if !defined(HAVE_SIGHOLD) || !defined(HAVE_SIGRELSE)
  74 #define BSD_SIGNALS
  75 #endif
  76 #endif
  77
  78 /* if FD_SET and friends aren't present, then fake something up */
  79 #ifndef FD_SET
  80 typedef int fd_set;
  81 #define FD_ZERO(x)     (*(x) = 0)
  82 #define FD_SET(f, x)   (*(x) = 1<<f)
  83 #endif
  84
  85 /* includes specific to top */
  86
  87 #include "top.h"
  88 #include "machine.h"
  89 #include "globalstate.h"
  90 #include "commands.h"
  91 #include "display.h"
  92 #include "screen.h"
  93 #include "boolean.h"
  94 #include "username.h"
  95 #include "utils.h"
  96 #include "version.h"
  97 #ifdef ENABLE_COLOR
  98 #include "color.h"
  99 #endif
 100
 101 /* definitions */
 102 #define BUFFERSIZE 4096
 103 #define JMP_RESUME 1
 104 #define JMP_RESIZE 2
 105
 106 /* externs for getopt: */
 107 extern int  optind;
 108 extern char *optarg;
 109
 110 /* statics */
 111 static char stdoutbuf[BUFFERSIZE];
 112 static jmp_buf jmp_int;
 113
 114 /* globals */
 115 char *myname;
 116
 117 void
 118 quit(int status)
 119
 120 {
 121     screen_end();
 122     chdir("/tmp");
 123     exit(status);
 124     /* NOTREACHED */
 125 }
 126
 127 /*
 128  *  signal handlers
 129  */
 130
 131 static void
 132 set_signal(int sig, RETSIGTYPE (*handler)(int))
 133
 134 {
 135 #ifdef HAVE_SIGACTION
 136     struct sigaction action;
 137
 138     action.sa_handler = handler;
 139     action.sa_flags = 0;
 140     (void) sigaction(sig, &action, NULL);
 141 #else
 142     (void) signal(sig, handler);
 143 #endif
 144 }
 145
 146 static void
 147 release_signal(int sig)
 148
 149 {
 150 #ifdef HAVE_SIGACTION
 151     sigset_t set;
 152     sigemptyset(&set);
 153     sigaddset(&set, sig);
 154     sigprocmask(SIG_UNBLOCK, &set, NULL);
 155 #endif
 156
 157 #ifdef HAVE_SIGHOLD
 158     sigrelse(sig);
 159 #endif
 160
 161 #ifdef BSD_SIGNALS
 162     (void) sigsetmask(sigblock(0) & ~(sigmask(sig)));
 163 #endif
 164 }
 165
 166 static RETSIGTYPE
 167 sig_leave(int i)        /* exit under normal conditions -- INT handler */
 168
 169 {
 170     screen_end();
 171     exit(EX_OK);
 172 }
 173
 174 static RETSIGTYPE
 175 sig_tstop(int i)        /* SIGTSTP handler */
 176
 177 {
 178     /* move to the lower left */
 179     screen_end();
 180     fflush(stdout);
 181
 182     /* default the signal handler action */
 183     set_signal(SIGTSTP, SIG_DFL);
 184
 185     /* unblock the TSTP signal */
 186     release_signal(SIGTSTP);
 187
 188     /* send ourselves a TSTP to stop the process */
 189     (void) kill(0, SIGTSTP);
 190
 191     /* reset the signal handler */
 192     set_signal(SIGTSTP, sig_tstop);
 193
 194     /* reinit screen */
 195     screen_reinit();
 196
 197     /* jump back to a known place in the main loop */
 198     longjmp(jmp_int, JMP_RESUME);
 199
 200     /* NOTREACHED */
 201 }
 202
 203 #ifdef SIGWINCH
 204 static RETSIGTYPE
 205 sig_winch(int i)                /* SIGWINCH handler */
 206
 207 {
 208     /* reascertain the screen dimensions */
 209     screen_getsize();
 210
 211     /* jump back to a known place in the main loop */
 212     longjmp(jmp_int, JMP_RESIZE);
 213 }
 214 #endif
 215
 216 #ifdef HAVE_SIGACTION
 217 static sigset_t signalset;
 218 #endif
 219
 220 static void *
 221 hold_signals(void)
 222
 223 {
 224 #ifdef HAVE_SIGACTION
 225     sigemptyset(&signalset);
 226     sigaddset(&signalset, SIGINT);
 227     sigaddset(&signalset, SIGQUIT);
 228     sigaddset(&signalset, SIGTSTP);
 229 #ifdef SIGWINCH
 230     sigaddset(&signalset, SIGWINCH);
 231 #endif
 232     sigprocmask(SIG_BLOCK, &signalset, NULL);
 233     return (void *)(&signalset);
 234 #endif
 235
 236 #ifdef HAVE_SIGHOLD
 237     sighold(SIGINT);
 238     sighold(SIGQUIT);
 239     sighold(SIGTSTP);
 240 #ifdef SIGWINCH
 241     sighold(SIGWINCH);
 242     return NULL;
 243 #endif
 244 #endif
 245
 246 #ifdef BSD_SIGNALS
 247     int mask;
 248 #ifdef SIGWINCH
 249     mask = sigblock(sigmask(SIGINT) | sigmask(SIGQUIT) |
 250                     sigmask(SIGTSTP) | sigmask(SIGWINCH));
 251 #else
 252     mask = sigblock(sigmask(SIGINT) | sigmask(SIGQUIT) | sigmask(SIGTSTP));
 253     return (void *)mask;
 254 #endif
 255 #endif
 256
 257 }
 258
 259 static void
 260 set_signals(void)
 261
 262 {
 263     (void) set_signal(SIGINT, sig_leave);
 264     (void) set_signal(SIGQUIT, sig_leave);
 265     (void) set_signal(SIGTSTP, sig_tstop);
 266 #ifdef SIGWINCH
 267     (void) set_signal(SIGWINCH, sig_winch);
 268 #endif
 269 }
 270
 271 static void
 272 release_signals(void *parm)
 273
 274 {
 275 #ifdef HAVE_SIGACTION
 276     sigprocmask(SIG_UNBLOCK, (sigset_t *)parm, NULL);
 277 #endif
 278
 279 #ifdef HAVE_SIGHOLD
 280     sigrelse(SIGINT);
 281     sigrelse(SIGQUIT);
 282     sigrelse(SIGTSTP);
 283 #ifdef SIGWINCH
 284     sigrelse(SIGWINCH);
 285 #endif
 286 #endif
 287
 288 #ifdef BSD_SIGNALS
 289     (void) sigsetmask((int)parm);
 290 #endif
 291 }
 292
 293 /*
 294  * void do_arguments(globalstate *gstate, int ac, char **av)
 295  *
 296  * Arguments processing.  gstate points to the global state,
 297  * ac and av are the arguments to process.  This can be called
 298  * multiple times with different sets of arguments.
 299  */
 300
 301 #ifdef HAVE_GETOPT_LONG
 302 static struct option longopts[] = {
 303     { "percpustates", no_argument, NULL, '1' },
 304     { "color", no_argument, NULL, 'C' },
 305     { "debug", no_argument, NULL, 'D' },
 306     { "system-procs", no_argument, NULL, 'S' },
 307     { "idle-procs", no_argument, NULL, 'I' },
 308     { "tag-names", no_argument, NULL, 'T' },
 309     { "all", no_argument, NULL, 'a' },
 310     { "batch", no_argument, NULL, 'b' },
 311     { "full-commands", no_argument, NULL, 'c' },
 312     { "interactive", no_argument, NULL, 'i' },
 313     { "quick", no_argument, NULL, 'q' },
 314     { "threads", no_argument, NULL, 't' },
 315     { "uids", no_argument, NULL, 'u' },
 316     { "version", no_argument, NULL, 'v' },
 317     { "delay", required_argument, NULL, 's' },
 318     { "displays", required_argument, NULL, 'd' },
 319     { "user", required_argument, NULL, 'U' },
 320     { "sort-order", required_argument, NULL, 'o' },
 321     { "pid", required_argument, NULL, 'p' },
 322     { "display-mode", required_argument, NULL, 'm' },
 323     { NULL, 0, NULL, 0 },
 324 };
 325 #endif
 326
 327
 328 static void
 329 do_arguments(globalstate *gstate, int ac, char **av)
 330
 331 {
 332     int i;
 333     double f;
 334
 335     /* this appears to keep getopt happy */
 336     optind = 1;
 337
 338 #ifdef HAVE_GETOPT_LONG
 339     while ((i = getopt_long(ac, av, "1CDSITabcinp:qtuvs:d:U:o:m:", longopts, NULL)) != -1)
 340 #else
 341     while ((i = getopt(ac, av, "1CDSITabcinp:qtuvs:d:U:o:m:")) != EOF)
 342 #endif
 343     {
 344         switch(i)
 345         {
 346         case '1':
 347             gstate->percpustates = !gstate->percpustates;
 348             break;
 349 #ifdef ENABLE_COLOR
 350         case 'C':
 351             gstate->use_color = !gstate->use_color;
 352             break;
 353 #endif
 354
 355         case 'D':
 356             debug_set(1);
 357             break;
 358
 359         case 'v':
 360             fprintf(stderr, "%s: version %s\n", myname, version_string());
 361             exit(EX_OK);
 362             break;
 363
 364         case 'b':
 365         case 'n':
 366             gstate->interactive = No;
 367             break;
 368
 369         case 'a':
 370             gstate->displays = Infinity;
 371             gstate->topn = Infinity;
 372             break;
 373
 374         case 'i':
 375             gstate->interactive = Yes;
 376             break;
 377
 378         case 'o':
 379             gstate->order_name = optarg;
 380             break;
 381
 382         case 'd':
 383             i = atoiwi(optarg);
 384             if (i == Invalid || i == 0)
 385             {
 386                 message_error(" Bad display count");
 387             }
 388             else
 389             {
 390                 gstate->displays = i;
 391             }
 392             break;
 393
 394         case 's':
 395             f = atof(optarg);
 396             if (f < 0 || (f == 0 && getuid() != 0))
 397             {
 398                 message_error(" Bad seconds delay");
 399             }
 400             else
 401             {
 402                 gstate->delay = f;
 403             }
 404             break;
 405
 406         case 'u':
 407             gstate->show_usernames = !gstate->show_usernames;
 408             break;
 409
 410         case 'U':
 411             i = userid(optarg);
 412             if (i == -1)
 413             {
 414                 message_error(" Unknown user '%s'", optarg);
 415             }
 416             else
 417             {
 418                 gstate->pselect.uid = i;
 419             }
 420             break;
 421
 422         case 'm':
 423             i = atoi(optarg);
 424             gstate->pselect.mode = i;
 425             break;
 426
 427         case 'S':
 428             gstate->pselect.system = !gstate->pselect.system;
 429             break;
 430
 431         case 'I':
 432             gstate->pselect.idle = !gstate->pselect.idle;
 433             break;
 434
 435 #ifdef ENABLE_COLOR
 436         case 'T':
 437             gstate->show_tags = 1;
 438             break;
 439 #endif
 440
 441         case 'c':
 442             gstate->pselect.fullcmd = !gstate->pselect.fullcmd;
 443             break;
 444
 445         case 't':
 446             gstate->pselect.threads = !gstate->pselect.threads;
 447             break;
 448
 449         case 'p':
 450             gstate->pselect.pid = atoi(optarg);
 451             break;
 452
 453         case 'q':               /* be quick about it */
 454             /* only allow this if user is really root */
 455             if (getuid() == 0)
 456             {
 457                 /* be very un-nice! */
 458                 (void) nice(-20);
 459             }
 460             else
 461             {
 462                 message_error(" Option -q can only be used by root");
 463             }
 464             break;
 465
 466         default:
 467             fprintf(stderr, "\
 468 Top version %s\n\
 469 Usage: %s [-1CISTabcinqtuv] [-d count] [-m mode] [-o field] [-p pid]\n\
 470            [-s time] [-U username] [number]\n",
 471                     version_string(), myname);
 472             exit(EX_USAGE);
 473         }
 474     }
 475
 476     /* get count of top processes to display */
 477     if (optind < ac && *av[optind])
 478     {
 479         if ((i = atoiwi(av[optind])) == Invalid)
 480         {
 481             message_error(" Process count not a number");
 482         }
 483         else
 484         {
 485             gstate->topn = i;
 486         }
 487     }
 488 }
 489
 490 static void
 491 do_display(globalstate *gstate)
 492
 493 {
 494     int active_procs;
 495     int i;
 496     time_t curr_time;
 497     caddr_t processes;
 498     struct system_info system_info;
 499     char *hdr;
 500
 501     /* get the time */
 502     time_mark(&(gstate->now));
 503     curr_time = (time_t)(gstate->now.tv_sec);
 504
 505     /* get the current stats */
 506     get_system_info(&system_info);
 507
 508     /* get the current processes */
 509     processes = get_process_info(&system_info, &(gstate->pselect), gstate->order_index);
 510
 511     /* determine number of processes to actually display */
 512     if (gstate->topn > 0)
 513     {
 514         /* this number will be the smallest of:  active processes,
 515            number user requested, number current screen accomodates */
 516         active_procs = system_info.P_ACTIVE;
 517         if (active_procs > gstate->topn)
 518         {
 519             active_procs = gstate->topn;
 520         }
 521         if (active_procs > gstate->max_topn)
 522         {
 523             active_procs = gstate->max_topn;
 524         }
 525     }
 526     else
 527     {
 528         /* dont show any */
 529         active_procs = 0;
 530     }
 531
 532 #ifdef HAVE_FORMAT_PROCESS_HEADER
 533     /* get the process header to use */
 534     hdr = format_process_header(&(gstate->pselect), processes, active_procs);
 535 #else
 536     hdr = gstate->header_text;
 537 #endif
 538
 539     /* full screen or update? */
 540     if (gstate->fulldraw)
 541     {
 542         display_clear();
 543         i_loadave(system_info.last_pid, system_info.load_avg);
 544         i_uptime(&(gstate->statics->boottime), &curr_time);
 545         i_timeofday(&curr_time);
 546         i_procstates(system_info.p_total, system_info.procstates, gstate->pselect.threads);
 547         if (gstate->show_cpustates)
 548         {
 549             i_cpustates(system_info.cpustates);
 550         }
 551         else
 552         {
 553             if (smart_terminal)
 554             {
 555                 z_cpustates();
 556             }
 557             gstate->show_cpustates = Yes;
 558         }
 559         i_kernel(system_info.kernel);
 560         i_memory(system_info.memory);
 561         i_swap(system_info.swap);
 562         i_message(&(gstate->now));
 563         i_header(hdr);
 564         for (i = 0; i < active_procs; i++)
 565         {
 566             i_process(i, format_next_process(processes, gstate->get_userid));
 567         }
 568         i_endscreen();
 569         if (gstate->smart_terminal)
 570         {
 571             gstate->fulldraw = No;
 572         }
 573     }
 574     else
 575     {
 576         u_loadave(system_info.last_pid, system_info.load_avg);
 577         u_uptime(&(gstate->statics->boottime), &curr_time);
 578         i_timeofday(&curr_time);
 579         u_procstates(system_info.p_total, system_info.procstates, gstate->pselect.threads);
 580         u_cpustates(system_info.cpustates);
 581         u_kernel(system_info.kernel);
 582         u_memory(system_info.memory);
 583         u_swap(system_info.swap);
 584         u_message(&(gstate->now));
 585         u_header(hdr);
 586         for (i = 0; i < active_procs; i++)
 587         {
 588             u_process(i, format_next_process(processes, gstate->get_userid));
 589         }
 590         u_endscreen();
 591     }
 592 }
 593
 594 #ifdef DEBUG
 595 void
 596 timeval_xdprint(char *s, struct timeval tv)
 597
 598 {
 599     xdprintf("%s %d.%06d\n", s, tv.tv_sec, tv.tv_usec);
 600 }
 601 #endif
 602
 603 static void
 604 do_wait(globalstate *gstate)
 605
 606 {
 607     struct timeval wait;
 608
 609     double2tv(&wait, gstate->delay);
 610     select(0, NULL, NULL, NULL, &wait);
 611 }
 612
 613 static void
 614 do_command(globalstate *gstate)
 615
 616 {
 617     int status;
 618     struct timeval wait = {0, 0};
 619     struct timeval now;
 620     fd_set readfds;
 621     unsigned char ch;
 622
 623     /* calculate new refresh time */
 624     gstate->refresh = gstate->now;
 625     double2tv(&now, gstate->delay);
 626     timeradd(&now, &gstate->refresh, &gstate->refresh);
 627     time_get(&now);
 628
 629     /* loop waiting for time to expire */
 630     do {
 631         /* calculate time to wait */
 632         if (gstate->delay > 0)
 633         {
 634             wait = gstate->refresh;
 635             wait.tv_usec -= now.tv_usec;
 636             if (wait.tv_usec < 0)
 637             {
 638                 wait.tv_usec += 1000000;
 639                 wait.tv_sec--;
 640             }
 641             wait.tv_sec -= now.tv_sec;
 642         }
 643
 644         /* set up arguments for select on stdin (0) */
 645         FD_ZERO(&readfds);
 646         FD_SET(STDIN_FILENO, &readfds);
 647
 648         /* wait for something to read or time out */
 649         if (select(32, &readfds, NULL, NULL, &wait) > 0)
 650         {
 651             /* read it */
 652             if (read(STDIN_FILENO, &ch, 1) != 1)
 653             {
 654                 /* read error */
 655                 message_error(" Read error on stdin");
 656                 quit(EX_DATAERR);
 657                 /*NOTREACHED*/
 658             }
 659
 660             /* mark pending messages as old */
 661             message_mark();
 662
 663             /* dispatch */
 664             status = command_process(gstate, (int)ch);
 665             switch(status)
 666             {
 667             case CMD_ERROR:
 668                 quit(EX_SOFTWARE);
 669                 /*NOTREACHED*/
 670
 671             case CMD_REFRESH:
 672                 return;
 673
 674             case CMD_UNKNOWN:
 675                 message_error(" Unknown command");
 676                 break;
 677
 678             case CMD_NA:
 679                 message_error(" Command not available");
 680             }
 681         }
 682
 683         /* get new time */
 684         time_get(&now);
 685     } while (timercmp(&now, &(gstate->refresh), < ));
 686 }
 687
 688 static void
 689 do_minidisplay(globalstate *gstate)
 690
 691 {
 692     double real_delay;
 693     struct system_info si;
 694
 695     /* save the real delay and substitute 1 second */
 696     real_delay = gstate->delay;
 697     gstate->delay = 1;
 698
 699     /* wait 1 second for a command */
 700     time_mark(&(gstate->now));
 701     do_command(gstate);
 702
 703     /* do a mini update that only updates the cpustates */
 704     get_system_info(&si);
 705     u_cpustates(si.cpustates);
 706
 707     /* restore the delay time */
 708     gstate->delay = real_delay;
 709
 710     /* done */
 711     i_endscreen();
 712 }
 713
 714 int
 715 main(int argc, char *argv[])
 716
 717 {
 718     char *env_top;
 719     char **preset_argv;
 720     int preset_argc = 0;
 721     void *mask;
 722     volatile int need_mini = 1;
 723     static char top[] = "top";
 724
 725     struct statics statics;
 726     globalstate *gstate;
 727
 728     /* get our name */
 729     if (argc > 0)
 730     {
 731         if ((myname = strrchr(argv[0], '/')) == 0)
 732         {
 733             myname = argv[0];
 734         }
 735         else
 736         {
 737             myname++;
 738         }
 739     } else
 740         myname = top;
 741
 742
 743     /* binary compatibility check */
 744 #ifdef HAVE_UNAME
 745     {
 746         struct utsname uts;
 747
 748         if (uname(&uts) == 0)
 749         {
 750             if (strcmp(uts.machine, UNAME_HARDWARE) != 0)
 751             {
 752                 fprintf(stderr, "%s: incompatible hardware platform\n",
 753                         myname);
 754                 exit(EX_UNAVAILABLE);
 755             }
 756         }
 757     }
 758 #endif
 759
 760     /* initialization */
 761     gstate = ecalloc(1, sizeof(globalstate));
 762     gstate->statics = &statics;
 763     time_mark(NULL);
 764
 765     /* preset defaults for various options */
 766     gstate->show_usernames = Yes;
 767     gstate->topn = DEFAULT_TOPN;
 768     gstate->delay = DEFAULT_DELAY;
 769     gstate->fulldraw = Yes;
 770     gstate->use_color = Yes;
 771     gstate->interactive = Maybe;
 772     gstate->percpustates = No;
 773
 774     /* preset defaults for process selection */
 775     gstate->pselect.idle = Yes;
 776     gstate->pselect.system = Yes;
 777     gstate->pselect.fullcmd = No;
 778     gstate->pselect.command = NULL;
 779     gstate->pselect.uid = -1;
 780     gstate->pselect.pid = -1;
 781     gstate->pselect.mode = 0;
 782
 783     /* use a large buffer for stdout */
 784 #ifdef HAVE_SETVBUF
 785     setvbuf(stdout, stdoutbuf, _IOFBF, BUFFERSIZE);
 786 #else
 787 #ifdef HAVE_SETBUFFER
 788     setbuffer(stdout, stdoutbuf, BUFFERSIZE);
 789 #endif
 790 #endif
 791
 792     /* get preset options from the environment */
 793     if ((env_top = getenv("TOP")) != NULL)
 794     {
 795         preset_argv = argparse(env_top, &preset_argc);
 796         preset_argv[0] = myname;
 797         do_arguments(gstate, preset_argc, preset_argv);
 798     }
 799
 800     /* process arguments */
 801     do_arguments(gstate, argc, argv);
 802
 803 #ifdef ENABLE_COLOR
 804     /* If colour has been turned on read in the settings. */
 805     env_top = getenv("TOPCOLOURS");
 806     if (!env_top)
 807     {
 808         env_top = getenv("TOPCOLORS");
 809     }
 810     /* must do something about error messages */
 811     color_env_parse(env_top);
 812     color_activate(gstate->use_color);
 813 #endif
 814
 815     /* in order to support forward compatability, we have to ensure that
 816        the entire statics structure is set to a known value before we call
 817        machine_init.  This way fields that a module does not know about
 818        will retain their default values */
 819     memzero((void *)&statics, sizeof(statics));
 820     statics.boottime = -1;
 821
 822     /* call the platform-specific init */
 823     if (machine_init(&statics) == -1)
 824     {
 825         exit(EX_SOFTWARE);
 826     }
 827
 828     /* create a helper list of sort order names */
 829     gstate->order_namelist = string_list(statics.order_names);
 830
 831     /* look up chosen sorting order */
 832     if (gstate->order_name != NULL)
 833     {
 834         int i;
 835
 836         if (statics.order_names == NULL)
 837         {
 838             message_error(" This platform does not support arbitrary ordering");
 839         }
 840         else if ((i = string_index(gstate->order_name,
 841                                    statics.order_names)) == -1)
 842         {
 843             message_error(" Sort order `%s' not recognized", gstate->order_name);
 844             message_error(" Recognized sort orders: %s", gstate->order_namelist);
 845         }
 846         else
 847         {
 848             gstate->order_index = i;
 849         }
 850     }
 851
 852     /* initialize extensions */
 853     init_username();
 854
 855     /* initialize termcap */
 856     gstate->smart_terminal = screen_readtermcap(gstate->interactive);
 857
 858     /* determine interactive state */
 859     if (gstate->interactive == Maybe)
 860     {
 861         gstate->interactive = smart_terminal;
 862     }
 863
 864     /* if displays were not specified, choose an appropriate default */
 865     if (gstate->displays == 0)
 866     {
 867         gstate->displays = gstate->smart_terminal ? Infinity: 1;
 868     }
 869
 870     /* we don't need a mini display when delay is less than 2
 871        seconds or when we are not on a smart terminal */
 872     if (gstate->delay <= 1 || !smart_terminal)
 873     {
 874         need_mini = 0;
 875     }
 876
 877 #ifndef HAVE_FORMAT_PROCESS_HEADER
 878     /* set constants for username/uid display */
 879     if (gstate->show_usernames)
 880     {
 881         gstate->header_text = format_header("USERNAME");
 882         gstate->get_userid = username;
 883     }
 884     else
 885     {
 886         gstate->header_text = format_header("   UID  ");
 887         gstate->get_userid = itoa7;
 888     }
 889 #endif
 890     gstate->pselect.usernames = gstate->show_usernames;
 891
 892     /* initialize display */
 893     if ((gstate->max_topn = display_init(&statics, gstate->percpustates)) == -1)
 894     {
 895         fprintf(stderr, "%s: display too small\n", myname);
 896         exit(EX_OSERR);
 897     }
 898
 899     /* check for infinity and for overflowed screen */
 900     if (gstate->topn == Infinity)
 901     {
 902         gstate->topn = INT_MAX;
 903     }
 904     else if (gstate->topn > gstate->max_topn)
 905     {
 906         message_error(" This terminal can only display %d processes",
 907                       gstate->max_topn);
 908     }
 909
 910 #ifdef ENABLE_COLOR
 911     /* producing a list of color tags is easy */
 912     if (gstate->show_tags)
 913     {
 914         color_dump(stdout);
 915         exit(EX_OK);
 916     }
 917 #endif
 918
 919     /* hold all signals while we initialize the screen */
 920     mask = hold_signals();
 921     screen_init();
 922
 923     /* set the signal handlers */
 924     set_signals();
 925
 926     /* longjmp re-entry point */
 927     /* set the jump buffer for long jumps out of signal handlers */
 928     if (setjmp(jmp_int) != 0)
 929     {
 930         /* this is where we end up after processing sigwinch or sigtstp */
 931
 932         /* tell display to resize its buffers, and get the new length */
 933         if ((gstate->max_topn = display_resize()) == -1)
 934         {
 935             /* thats bad */
 936             quit(EX_OSERR);
 937             /*NOTREACHED*/
 938         }
 939
 940         /* set up for a full redraw, and get the current line count */
 941         gstate->fulldraw = Yes;
 942
 943         /* safe to release the signals now */
 944         release_signals(mask);
 945     }
 946     else
 947     {
 948         /* release the signals */
 949         release_signals(mask);
 950
 951         /* some systems require a warmup */
 952         /* always do a warmup for batch mode */
 953         if (gstate->interactive == 0 || statics.flags.warmup)
 954         {
 955             struct system_info system_info;
 956             struct timeval timeout;
 957
 958             time_mark(&(gstate->now));
 959             get_system_info(&system_info);
 960             (void)get_process_info(&system_info, &gstate->pselect, 0);
 961             timeout.tv_sec = 1;
 962             timeout.tv_usec = 0;
 963             select(0, NULL, NULL, NULL, &timeout);
 964
 965             /* if we've warmed up, then we can show good states too */
 966             gstate->show_cpustates = Yes;
 967             need_mini = 0;
 968         }
 969     }
 970
 971     /* main loop */
 972     while ((gstate->displays == -1) || (--gstate->displays > 0))
 973     {
 974         do_display(gstate);
 975         if (gstate->interactive)
 976         {
 977             if (need_mini)
 978             {
 979                 do_minidisplay(gstate);
 980                 need_mini = 0;
 981             }
 982             do_command(gstate);
 983         }
 984         else
 985         {
 986             do_wait(gstate);
 987         }
 988     }
 989
 990     /* do one last display */
 991     do_display(gstate);
 992
 993     quit(EX_OK);
 994     /* NOTREACHED */
 995     return 1; /* Keep compiler quiet. */
 996 }