top.c

在Linux/UNIX下

char *copyright =
    "Copyright (c) 1984 through 2004, William LeFebvre";

/*
 *  Top users/processes display for Unix
 *  Version 3
 *
 *  This program may be freely redistributed,
 *  but this entire comment MUST remain intact.
 *
 *  Copyright (c) 1984, 1989, William LeFebvre, Rice University
 *  Copyright (c) 1989 - 1994, William LeFebvre, Northwestern University
 *  Copyright (c) 1994, 1995, William LeFebvre, Argonne National Laboratory
 *  Copyright (c) 1996, William LeFebvre, Group sys Consulting
 */

/*
 *  See the file "Changes" for information on version-to-version changes.
 */

/*
 *  This file contains "main" and other high-level routines.
 */

/*
 * The following preprocessor variables, when defined, are used to
 * distinguish between different Unix implementations:
 *
 *	SIGHOLD  - use SVR4 sighold function when defined
 *	SIGRELSE - use SVR4 sigrelse function when defined
 *	FD_SET   - macros FD_SET and FD_ZERO are used when defined
 */

#include "os.h"
#include <signal.h>
#include <setjmp.h>
#include <ctype.h>
#include <sys/time.h>

/* includes specific to top */
#include "display.h"		/* interface to display package */
#include "screen.h"		/* interface to screen package */
#include "top.h"
#include "top.local.h"
#include "boolean.h"
#include "machine.h"
#include "utils.h"

/* Size of the stdio buffer given to stdout */
#define Buffersize	2048

/* The buffer that stdio will use */
char stdoutbuf[Buffersize];

/* build Signal masks */
#define Smask(s)	(1 << ((s) - 1))

/* for getopt: */
extern int  optind;
extern char *optarg;

/* imported from screen.c */
extern int overstrike;

/* signal handling routines */
sigret_t leave();
sigret_t onalrm();
sigret_t tstop();
#ifdef SIGWINCH
sigret_t winch();
#endif

/* internal routines */
void quit();

/* values which need to be accessed by signal handlers */
static int max_topn;		/* maximum displayable processes */

/* miscellaneous things */
char *myname = "top";
jmp_buf jmp_int;

/* routines that don't return int */

char *username();
char *ctime();
char *kill_procs();
char *renice_procs();

#ifdef ORDER
extern int (*proc_compares[])();
#else
extern int proc_compare();
#endif
time_t time();

caddr_t get_process_info();

/* different routines for displaying the user's identification */
/* (values assigned to get_userid) */
char *username();
char *itoa7();

/* display routines that need to be predeclared */
int i_loadave();
int u_loadave();
int i_procstates();
int u_procstates();
int i_cpustates();
int u_cpustates();
int i_memory();
int u_memory();
int i_message();
int u_message();
int i_header();
int u_header();
int i_process();
int u_process();

/* pointers to display routines */
int (*d_loadave)() = i_loadave;
int (*d_procstates)() = i_procstates;
int (*d_cpustates)() = i_cpustates;
int (*d_memory)() = i_memory;
int (*d_message)() = i_message;
int (*d_header)() = i_header;
int (*d_process)() = i_process;


main(argc, argv)

int  argc;
char *argv[];

{
    register int i;
    register int active_procs;
    register int change;

    struct system_info system_info;
    struct statics statics;
    caddr_t processes;

    static char tempbuf1[50];
    static char tempbuf2[50];
    int old_sigmask;		/* only used for BSD-style signals */
    int topn = Default_TOPN;
    int delay = Default_DELAY;
    int displays = 0;		/* indicates unspecified */
    time_t curr_time;
    char *(*get_userid)() = username;
    char *uname_field = "USERNAME";
    char *header_text;
    char *env_top;
    char **preset_argv;
    int  preset_argc = 0;
    char **av;
    int  ac;
    char dostates = No;
    char do_unames = Yes;
    char interactive = Maybe;
    char warnings = 0;
#if Default_TOPN == Infinity
    char topn_specified = No;
#endif
    char ch;
    char *iptr;
    char no_command = 1;
    struct timeval timeout;
    struct process_select ps;
#ifdef ORDER
    char *order_name = NULL;
    int order_index = 0;
#endif
#ifndef FD_SET
    /* FD_SET and friends are not present:  fake it */
    typedef int fd_set;
#define FD_ZERO(x)     (*(x) = 0)
#define FD_SET(f, x)   (*(x) = 1<<f)
#endif
    fd_set readfds;

#ifdef ORDER
    static char command_chars[] = "\f qh?en#sdkriIuo";
#else
    static char command_chars[] = "\f qh?en#sdkriIu";
#endif
/* these defines enumerate the "strchr"s of the commands in command_chars */
#define CMD_redraw	0
#define CMD_update	1
#define CMD_quit	2
#define CMD_help1	3
#define CMD_help2	4
#define CMD_OSLIMIT	4    /* terminals with OS can only handle commands */
#define CMD_errors	5    /* less than or equal to CMD_OSLIMIT	   */
#define CMD_number1	6
#define CMD_number2	7
#define CMD_delay	8
#define CMD_displays	9
#define CMD_kill	10
#define CMD_renice	11
#define CMD_idletog     12
#define CMD_idletog2    13
#define CMD_user	14
#ifdef ORDER
#define CMD_order       15
#endif

    /* set the buffer for stdout */
#ifdef DEBUG
    extern FILE *debug;
    debug = fopen("debug.run", "w");
    setbuffer(stdout, NULL, 0);
#else
    setbuffer(stdout, stdoutbuf, Buffersize);
#endif

    /* get our name */
    if (argc > 0)
    {
	if ((myname = strrchr(argv[0], '/')) == 0)
	{
	    myname = argv[0];
	}
	else
	{
	    myname++;
	}
    }

    /* initialize some selection options */
    ps.idle    = Yes;
    ps.system  = No;
    ps.uid     = -1;
    ps.command = NULL;

    /* get preset options from the environment */
    if ((env_top = getenv("TOP")) != NULL)
    {
	av = preset_argv = argparse(env_top, &preset_argc);
	ac = preset_argc;

	/* set the dummy argument to an explanatory message, in case
	   getopt encounters a bad argument */
	preset_argv[0] = "while processing environment";
    }

    /* process options */
    do {
	/* if we're done doing the presets, then process the real arguments */
	if (preset_argc == 0)
	{
	    ac = argc;
	    av = argv;

	    /* this should keep getopt happy... */
	    optind = 1;
	}

	while ((i = getopt(ac, av, "SIbinquvs:d:U:o:")) != EOF)
	{
	    switch(i)
	    {
	      case 'v':			/* show version number */
		fprintf(stderr, "%s: version %s\n",
			myname, version_string());
		exit(1);
		break;

	      case 'u':			/* toggle uid/username display */
		do_unames = !do_unames;
		break;

	      case 'U':			/* display only username's processes */
		if ((ps.uid = userid(optarg)) == -1)
		{
		    fprintf(stderr, "%s: unknown user\n", optarg);
		    exit(1);
		}
		break;

	      case 'S':			/* show system processes */
		ps.system = !ps.system;
		break;

	      case 'I':                   /* show idle processes */
		ps.idle = !ps.idle;
		break;

	      case 'i':			/* go interactive regardless */
		interactive = Yes;
		break;

	      case 'n':			/* batch, or non-interactive */
	      case 'b':
		interactive = No;
		break;

	      case 'd':			/* number of displays to show */
		if ((i = atoiwi(optarg)) == Invalid || i == 0)
		{
		    fprintf(stderr,
			"%s: warning: display count should be positive -- option ignored\n",
			myname);
		    warnings++;
		}
		else
		{
		    displays = i;
		}
		break;

	      case 's':
		if ((delay = atoi(optarg)) < 0 || (delay == 0 && getuid() != 0))
		{
		    fprintf(stderr,
			"%s: warning: seconds delay should be positive -- using default\n",
			myname);
		    delay = Default_DELAY;
		    warnings++;
		}
		break;

	      case 'q':		/* be quick about it */
		/* only allow this if user is really root */
		if (getuid() == 0)
		{
		    /* be very un-nice! */
		    (void) nice(-20);
		}
		else
		{
		    fprintf(stderr,
			"%s: warning: `-q' option can only be used by root\n",
			myname);
		    warnings++;
		}
		break;

	      case 'o':		/* select sort order */
#ifdef ORDER
		order_name = optarg;
#else
		fprintf(stderr,
			"%s: this platform does not support arbitrary ordering.  Sorry.\n",
			myname);
		warnings++;
#endif
		break;

	      default:
		fprintf(stderr, "\
Top version %s\n\
Usage: %s [-ISbinqu] [-d x] [-s x] [-o field] [-U username] [number]\n",
			version_string(), myname);
		exit(1);
	    }
	}

	/* get count of top processes to display (if any) */
	if (optind < ac)
	{
	    if ((topn = atoiwi(av[optind])) == Invalid)
	    {
		fprintf(stderr,
			"%s: warning: process display count should be non-negative -- using default\n",
			myname);
		warnings++;
	    }
#if Default_TOPN == Infinity
            else
	    {
		topn_specified = Yes;
	    }
#endif
	}

	/* tricky:  remember old value of preset_argc & set preset_argc = 0 */
	i = preset_argc;
	preset_argc = 0;

    /* repeat only if we really did the preset arguments */
    } while (i != 0);

    /* set constants for username/uid display correctly */
    if (!do_unames)
    {
	uname_field = "   UID  ";
	get_userid = itoa7;
    }

    /* initialize the kernel memory interface */
    if (machine_init(&statics) == -1)
    {
	exit(1);
    }

#ifdef ORDER
    /* determine sorting order index, if necessary */
    if (order_name != NULL)
    {
	if ((order_index = string_index(order_name, statics.order_names)) == -1)
	{
	    char **pp;

	    fprintf(stderr, "%s: '%s' is not a recognized sorting order.\n",
		    myname, order_name);
	    fprintf(stderr, "\tTry one of these:");
	    pp = statics.order_names;
	    while (*pp != NULL)
	    {
		fprintf(stderr, " %s", *pp++);
	    }
	    fputc('\n', stderr);
	    exit(1);
	}
    }
#endif

#ifdef no_initialization_needed
    /* initialize the hashing stuff */
    if (do_unames)
    {
	init_hash();
    }
#endif

    /* initialize termcap */
    init_termcap(interactive);

    /* get the string to use for the process area header */
    header_text = format_header(uname_field);

    /* initialize display interface */
    if ((max_topn = display_init(&statics)) == -1)
    {
	fprintf(stderr, "%s: can't allocate sufficient memory\n", myname);
	exit(4);
    }
    
    /* print warning if user requested more processes than we can display */
    if (topn > max_topn)
    {
	fprintf(stderr,
		"%s: warning: this terminal can only display %d processes.\n",
		myname, max_topn);
	warnings++;
    }

    /* adjust for topn == Infinity */
    if (topn == Infinity)
    {
	/*
	 *  For smart terminals, infinity really means everything that can
	 *  be displayed, or Largest.
	 *  On dumb terminals, infinity means every process in the system!
	 *  We only really want to do that if it was explicitly specified.
	 *  This is always the case when "Default_TOPN != Infinity".  But if
	 *  topn wasn't explicitly specified and we are on a dumb terminal
	 *  and the default is Infinity, then (and only then) we use
	 *  "Nominal_TOPN" instead.
	 */
#if Default_TOPN == Infinity
	topn = smart_terminal ? Largest :
		    (topn_specified ? Largest : Nominal_TOPN);
#else
	topn = Largest;
#endif
    }

    /* set header display accordingly */
    display_header(topn > 0);

    /* determine interactive state */
    if (interactive == Maybe)
    {
	interactive = smart_terminal;
    }

    /* if # of displays not specified, fill it in */
    if (displays == 0)
    {
	displays = smart_terminal ? Infinity : 1;
    }

    /* hold interrupt signals while setting up the screen and the handlers */
#ifdef SIGHOLD
    sighold(SIGINT);
    sighold(SIGQUIT);
    sighold(SIGTSTP);
#else
    old_sigmask = sigblock(Smask(SIGINT) | Smask(SIGQUIT) | Smask(SIGTSTP));
#endif
    init_screen();
    (void) signal(SIGINT, leave);
    (void) signal(SIGQUIT, leave);
    (void) signal(SIGTSTP, tstop);
#ifdef SIGWINCH
    (void) signal(SIGWINCH, winch);
#endif
#ifdef SIGRELSE
    sigrelse(SIGINT);
    sigrelse(SIGQUIT);
    sigrelse(SIGTSTP);
#else
    (void) sigsetmask(old_sigmask);
#endif
    if (warnings)
    {
	fputs("....", stderr);
	fflush(stderr);			/* why must I do this? */
	sleep((unsigned)(3 * warnings));