top.c

在Linux/UNIX下

	fputc('\n', stderr);
    }

    /* setup the jump buffer for stops */
    if (setjmp(jmp_int) != 0)
    {
	/* control ends up here after an interrupt */
	reset_display();
    }

    /*
     *  main loop -- repeat while display count is positive or while it
     *		indicates infinity (by being -1)
     */

    while ((displays == -1) || (displays-- > 0))
    {
	/* get the current stats */
	get_system_info(&system_info);

	/* get the current set of processes */
	processes =
		get_process_info(&system_info,
				 &ps,
#ifdef ORDER
				 proc_compares[order_index]);
#else
				 proc_compare);
#endif

	/* display the load averages */
	(*d_loadave)(system_info.last_pid,
		     system_info.load_avg);

	/* display the current time */
	/* this method of getting the time SHOULD be fairly portable */
	time(&curr_time);
	i_timeofday(&curr_time);

	/* display process state breakdown */
	(*d_procstates)(system_info.p_total,
			system_info.procstates);

	/* display the cpu state percentage breakdown */
	if (dostates)	/* but not the first time */
	{
	    (*d_cpustates)(system_info.cpustates);
	}
	else
	{
	    /* we'll do it next time */
	    if (smart_terminal)
	    {
		z_cpustates();
	    }
	    else
	    {
		putchar('\n');
	    }
	    dostates = Yes;
	}

	/* display memory stats */
	(*d_memory)(system_info.memory);

	/* handle message area */
	(*d_message)();

	/* update the header area */
	(*d_header)(header_text);
    
	if (topn > 0)
	{
	    /* determine number of processes to actually display */
	    /* this number will be the smallest of:  active processes,
	       number user requested, number current screen accomodates */
	    active_procs = system_info.P_ACTIVE;
	    if (active_procs > topn)
	    {
		active_procs = topn;
	    }
	    if (active_procs > max_topn)
	    {
		active_procs = max_topn;
	    }

	    /* now show the top "n" processes. */
	    for (i = 0; i < active_procs; i++)
	    {
		(*d_process)(i, format_next_process(processes, get_userid));
	    }
	}
	else
	{
	    i = 0;
	}

	/* do end-screen processing */
	u_endscreen(i);

	/* now, flush the output buffer */
	if (fflush(stdout) != 0)
	{
	    new_message(MT_standout, " Write error on stdout");
	    putchar('\r');
	    quit(1);
	    /*NOTREACHED*/
	}

	/* only do the rest if we have more displays to show */
	if (displays)
	{
	    /* switch out for new display on smart terminals */
	    if (smart_terminal)
	    {
		if (overstrike)
		{
		    reset_display();
		}
		else
		{
		    d_loadave = u_loadave;
		    d_procstates = u_procstates;
		    d_cpustates = u_cpustates;
		    d_memory = u_memory;
		    d_message = u_message;
		    d_header = u_header;
		    d_process = u_process;
		}
	    }
    
	    no_command = Yes;
	    if (!interactive)
	    {
		/* set up alarm */
		(void) signal(SIGALRM, onalrm);
		(void) alarm((unsigned)delay);
    
		/* wait for the rest of it .... */
		pause();
	    }
	    else while (no_command)
	    {
		/* assume valid command unless told otherwise */
		no_command = No;

		/* set up arguments for select with timeout */
		FD_ZERO(&readfds);
		FD_SET(0, &readfds);		/* for standard input */
		timeout.tv_sec  = delay;
		timeout.tv_usec = 0;

		/* wait for either input or the end of the delay period */
		if (select(32, &readfds, (fd_set *)NULL, (fd_set *)NULL, &timeout) > 0)
		{
		    int newval;
		    char *errmsg;
    
		    /* something to read -- clear the message area first */
		    clear_message();

		    /* now read it and convert to command strchr */
		    /* (use "change" as a temporary to hold strchr) */
		    if (read(0, &ch, 1) != 1)
		    {
			/* read error: either 0 or -1 */
			new_message(MT_standout, " Read error on stdin");
			putchar('\r');
			quit(1);
			/*NOTREACHED*/
		    }
		    if ((iptr = strchr(command_chars, ch)) == NULL)
		    {
			/* illegal command */
			new_message(MT_standout, " Command not understood");
			putchar('\r');
			no_command = Yes;
		    }
		    else
		    {
			change = iptr - command_chars;
			if (overstrike && change > CMD_OSLIMIT)
			{
			    /* error */
			    new_message(MT_standout,
			    " Command cannot be handled by this terminal");
			    putchar('\r');
			    no_command = Yes;
			}
			else switch(change)
			{
			    case CMD_redraw:	/* redraw screen */
				reset_display();
				break;
    
			    case CMD_update:	/* merely update display */
				/* is the load average high? */
				if (system_info.load_avg[0] > LoadMax)
				{
				    /* yes, go home for visual feedback */
				    go_home();
				    fflush(stdout);
				}
				break;
	    
			    case CMD_quit:	/* quit */
				quit(0);
				/*NOTREACHED*/
				break;
	    
			    case CMD_help1:	/* help */
			    case CMD_help2:
				reset_display();
				clear();
				show_help();
				standout("Hit any key to continue: ");
				fflush(stdout);
				(void) read(0, &ch, 1);
				break;
	
			    case CMD_errors:	/* show errors */
				if (error_count() == 0)
				{
				    new_message(MT_standout,
					" Currently no errors to report.");
				    putchar('\r');
				    no_command = Yes;
				}
				else
				{
				    reset_display();
				    clear();
				    show_errors();
				    standout("Hit any key to continue: ");
				    fflush(stdout);
				    (void) read(0, &ch, 1);
				}
				break;
	
			    case CMD_number1:	/* new number */
			    case CMD_number2:
				new_message(MT_standout,
				    "Number of processes to show: ");
				newval = readline(tempbuf1, 8, Yes);
				if (newval > -1)
				{
				    if (newval > max_topn)
				    {
					new_message(MT_standout | MT_delayed,
					  " This terminal can only display %d processes.",
					  max_topn);
					putchar('\r');
				    }

				    if (newval == 0)
				    {
					/* inhibit the header */
					display_header(No);
				    }
				    else if (newval > topn && topn == 0)
				    {
					/* redraw the header */
					display_header(Yes);
					d_header = i_header;
				    }
				    topn = newval;
				}
				break;
	    
			    case CMD_delay:	/* new seconds delay */
				new_message(MT_standout, "Seconds to delay: ");
				if ((i = readline(tempbuf1, 8, Yes)) > -1)
				{
				    if ((delay = i) == 0 && getuid() != 0)
				    {
					delay = 1;
				    }
				}
				clear_message();
				break;
	
			    case CMD_displays:	/* change display count */
				new_message(MT_standout,
					"Displays to show (currently %s): ",
					displays == -1 ? "infinite" :
							 itoa(displays));
				if ((i = readline(tempbuf1, 10, Yes)) > 0)
				{
				    displays = i;
				}
				else if (i == 0)
				{
				    quit(0);
				}
				clear_message();
				break;
    
			    case CMD_kill:	/* kill program */
				new_message(0, "kill ");
				if (readline(tempbuf2, sizeof(tempbuf2), No) > 0)
				{
				    if ((errmsg = kill_procs(tempbuf2)) != NULL)
				    {
					new_message(MT_standout, errmsg);
					putchar('\r');
					no_command = Yes;
				    }
				}
				else
				{
				    clear_message();
				}
				break;
	    
			    case CMD_renice:	/* renice program */
				new_message(0, "renice ");
				if (readline(tempbuf2, sizeof(tempbuf2), No) > 0)
				{
				    if ((errmsg = renice_procs(tempbuf2)) != NULL)
				    {
					new_message(MT_standout, errmsg);
					putchar('\r');
					no_command = Yes;
				    }
				}
				else
				{
				    clear_message();
				}
				break;

			    case CMD_idletog:
			    case CMD_idletog2:
				ps.idle = !ps.idle;
				new_message(MT_standout | MT_delayed,
				    " %sisplaying idle processes.",
				    ps.idle ? "D" : "Not d");
				putchar('\r');
				break;

			    case CMD_user:
				new_message(MT_standout,
				    "Username to show: ");
				if (readline(tempbuf2, sizeof(tempbuf2), No) > 0)
				{
				    if (tempbuf2[0] == '+' &&
					tempbuf2[1] == '\0')
				    {
					ps.uid = -1;
				    }
				    else if ((i = userid(tempbuf2)) == -1)
				    {
					new_message(MT_standout,
					    " %s: unknown user", tempbuf2);
					no_command = Yes;
				    }
				    else
				    {
					ps.uid = i;
				    }
				    putchar('\r');
				}
				else
				{
				    clear_message();
				}
				break;
	    
#ifdef ORDER
			    case CMD_order:
				new_message(MT_standout,
				    "Order to sort: ");
				if (readline(tempbuf2, sizeof(tempbuf2), No) > 0)
				{
				  if ((i = string_index(tempbuf2, statics.order_names)) == -1)
					{
					  new_message(MT_standout,
					      " %s: unrecognized sorting order", tempbuf2);
					  no_command = Yes;
				    }
				    else
				    {
					order_index = i;
				    }
				    putchar('\r');
				}
				else
				{
				    clear_message();
				}
				break;
#endif
	    
			    default:
				new_message(MT_standout, " BAD CASE IN SWITCH!");
				putchar('\r');
			}
		    }

		    /* flush out stuff that may have been written */
		    fflush(stdout);
		}
	    }
	}
    }

#ifdef DEBUG
    fclose(debug);
#endif
    quit(0);
    /*NOTREACHED*/
}

/*
 *  reset_display() - reset all the display routine pointers so that entire
 *	screen will get redrawn.
 */

reset_display()

{
    d_loadave    = i_loadave;
    d_procstates = i_procstates;
    d_cpustates  = i_cpustates;
    d_memory     = i_memory;
    d_message	 = i_message;
    d_header	 = i_header;
    d_process	 = i_process;
}

/*
 *  signal handlers
 */

sigret_t leave()	/* exit under normal conditions -- INT handler */

{
    end_screen();
    exit(0);
}

sigret_t tstop(i)	/* SIGTSTP handler */

int i;

{
    /* move to the lower left */
    end_screen();
    fflush(stdout);

    /* default the signal handler action */
    (void) signal(SIGTSTP, SIG_DFL);

    /* unblock the signal and send ourselves one */
#ifdef SIGRELSE
    sigrelse(SIGTSTP);
#else
    (void) sigsetmask(sigblock(0) & ~(1 << (SIGTSTP - 1)));
#endif
    (void) kill(0, SIGTSTP);

    /* reset the signal handler */
    (void) signal(SIGTSTP, tstop);

    /* reinit screen */
    reinit_screen();

    /* jump to appropriate place */
    longjmp(jmp_int, 1);

    /*NOTREACHED*/
}

#ifdef SIGWINCH
sigret_t winch(i)		/* SIGWINCH handler */

int i;

{
    /* reascertain the screen dimensions */
    get_screensize();

    /* tell display to resize */
    max_topn = display_resize();

    /* reset the signal handler */
    (void) signal(SIGWINCH, winch);

    /* jump to appropriate place */
    longjmp(jmp_int, 1);
}
#endif

void quit(status)		/* exit under duress */

int status;

{
    end_screen();
    exit(status);
    /*NOTREACHED*/
}

sigret_t onalrm()	/* SIGALRM handler */

{
    /* this is only used in batch mode to break out of the pause() */
    /* return; */
}