xref: /openbsd/usr.bin/top/display.c (revision 09467b48)
1 /* $OpenBSD: display.c,v 1.63 2020/07/26 21:59:16 kn Exp $	 */
2 
3 /*
4  *  Top users/processes display for Unix
5  *  Version 3
6  *
7  * Copyright (c) 1984, 1989, William LeFebvre, Rice University
8  * Copyright (c) 1989, 1990, 1992, William LeFebvre, Northwestern University
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR OR HIS EMPLOYER BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 /*
32  *  This file contains the routines that display information on the screen.
33  *  Each section of the screen has two routines:  one for initially writing
34  *  all constant and dynamic text, and one for only updating the text that
35  *  changes.  The prefix "i_" is used on all the "initial" routines and the
36  *  prefix "u_" is used for all the "updating" routines.
37  *
38  *  ASSUMPTIONS:
39  *        None of the "i_" routines use any of the termcap capabilities.
40  *        In this way, those routines can be safely used on terminals that
41  *        have minimal (or nonexistent) terminal capabilities.
42  *
43  *        The routines are called in this order:  *_loadave, i_timeofday,
44  *        *_procstates, *_cpustates, *_memory, *_message, *_header,
45  *        *_process, u_endscreen.
46  */
47 
48 #include <sys/types.h>
49 #include <sys/time.h>
50 #include <sys/sched.h>
51 #include <curses.h>
52 #include <errno.h>
53 #include <stdio.h>
54 #include <ctype.h>
55 #include <err.h>
56 #include <signal.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include <unistd.h>
60 #include <stdbool.h>
61 
62 #include "screen.h"		/* interface to screen package */
63 #include "layout.h"		/* defines for screen position layout */
64 #include "display.h"
65 #include "top.h"
66 #include "machine.h"		/* we should eliminate this!!! */
67 #include "utils.h"
68 
69 #ifdef DEBUG
70 FILE           *debug;
71 #endif
72 
73 static int      display_width = MAX_COLS;
74 
75 static char    *cpustates_tag(int);
76 static int      string_count(char **);
77 static void     summary_format(char *, size_t, int *, char **);
78 static int	readlinedumb(char *, int);
79 
80 #define lineindex(l) ((l)*display_width)
81 
82 /* things initialized by display_init and used throughout */
83 
84 /* buffer of proc information lines for display updating */
85 char           *screenbuf = NULL;
86 
87 static char   **procstate_names;
88 static char   **cpustate_names;
89 static char   **memory_names;
90 
91 static int      num_cpustates;
92 
93 static int     *cpustate_columns;
94 static int      cpustate_total_length;
95 
96 /* display ips */
97 int y_mem;
98 int y_message;
99 int y_header;
100 int y_idlecursor;
101 int y_procs;
102 extern int ncpu;
103 extern int ncpuonline;
104 extern int combine_cpus;
105 extern struct process_select ps;
106 
107 int header_status = true;
108 
109 static int
110 empty(void)
111 {
112 	return OK;
113 }
114 
115 static int
116 myfputs(const char *s)
117 {
118 	return fputs(s, stdout);
119 }
120 
121 static int (*addstrp)(const char *);
122 static int (*printwp)(const char *, ...);
123 static int (*standoutp)(void);
124 static int (*standendp)(void);
125 
126 int
127 display_resize(void)
128 {
129 	int cpu_lines, display_lines;
130 
131 	ncpuonline = getncpuonline();
132 	cpu_lines = (combine_cpus ? 1 : ncpuonline);
133 	y_mem = 2 + cpu_lines;
134 	y_header = 4 + cpu_lines;
135 	y_procs = 5 + cpu_lines;
136 
137 	/* calculate the current dimensions */
138 	/* if operating in "dumb" mode, we only need one line */
139 	display_lines = smart_terminal ? screen_length - y_procs : 1;
140 
141 	y_idlecursor = y_message = 3 + (combine_cpus ? 1 : ncpuonline);
142 	if (screen_length <= y_message)
143 		y_idlecursor = y_message = screen_length - 1;
144 
145 	/*
146 	 * we don't want more than MAX_COLS columns, since the
147 	 * machine-dependent modules make static allocations based on
148 	 * MAX_COLS and we don't want to run off the end of their buffers
149 	 */
150 	display_width = screen_width;
151 	if (display_width >= MAX_COLS)
152 		display_width = MAX_COLS - 1;
153 
154 	if (display_lines < 0)
155 		display_lines = 0;
156 
157 	/* return number of lines available */
158 	/* for dumb terminals, pretend like we can show any amount */
159 	return (smart_terminal ? display_lines : Largest);
160 }
161 
162 int
163 display_init(struct statics * statics)
164 {
165 	int display_lines, *ip, i;
166 	char **pp;
167 
168 	if (smart_terminal) {
169 		addstrp = addstr;
170 		printwp = printw;
171 		standoutp = standout;
172 		standendp = standend;
173 	} else {
174 		addstrp = myfputs;
175 		printwp = printf;
176 		standoutp = empty;
177 		standendp = empty;
178 	}
179 
180 	/* call resize to do the dirty work */
181 	display_lines = display_resize();
182 
183 	/* only do the rest if we need to */
184 	/* save pointers and allocate space for names */
185 	procstate_names = statics->procstate_names;
186 
187 	cpustate_names = statics->cpustate_names;
188 	num_cpustates = string_count(cpustate_names);
189 
190 	cpustate_columns = calloc(num_cpustates, sizeof(int));
191 	if (cpustate_columns == NULL)
192 		err(1, NULL);
193 
194 	memory_names = statics->memory_names;
195 
196 	/* calculate starting columns where needed */
197 	cpustate_total_length = 0;
198 	pp = cpustate_names;
199 	ip = cpustate_columns;
200 	while (*pp != NULL) {
201 		if ((i = strlen(*pp++)) > 0) {
202 			*ip++ = cpustate_total_length;
203 			cpustate_total_length += i + 8;
204 		}
205 	}
206 
207 	/* return number of lines available */
208 	return (display_lines);
209 }
210 
211 static void
212 format_uptime(char *buf, size_t buflen)
213 {
214 	time_t uptime;
215 	int days, hrs, mins;
216 	struct timespec boottime;
217 
218 	/*
219 	 * Print how long system has been up.
220 	 */
221 	if (clock_gettime(CLOCK_BOOTTIME, &boottime) != -1) {
222 		uptime = boottime.tv_sec;
223 		uptime += 30;
224 		days = uptime / (3600 * 24);
225 		uptime %= (3600 * 24);
226 		hrs = uptime / 3600;
227 		uptime %= 3600;
228 		mins = uptime / 60;
229 		if (days > 0)
230 			snprintf(buf, buflen, "up %d day%s, %2d:%02d",
231 			    days, days > 1 ? "s" : "", hrs, mins);
232 		else
233 			snprintf(buf, buflen, "up %2d:%02d",
234 			    hrs, mins);
235 	}
236 }
237 
238 
239 void
240 i_loadave(pid_t mpid, double *avenrun)
241 {
242 	if (screen_length > 1 || !smart_terminal) {
243 		int i;
244 
245 		move(0, 0);
246 		clrtoeol();
247 
248 		addstrp("load averages");
249 		/* mpid == -1 implies this system doesn't have an _mpid */
250 		if (mpid != -1)
251 			printwp("last pid: %5ld;  ", (long) mpid);
252 
253 		for (i = 0; i < 3; i++)
254 			printwp("%c %5.2f", i == 0 ? ':' : ',', avenrun[i]);
255 	}
256 
257 }
258 
259 /*
260  *  Display the current time.
261  *  "ctime" always returns a string that looks like this:
262  *
263  *	Sun Sep 16 01:03:52 1973
264  *      012345678901234567890123
265  *	          1         2
266  *
267  *  We want indices 11 thru 18 (length 8).
268  */
269 
270 void
271 i_timeofday(time_t * tod)
272 {
273 	static char buf[30];
274 
275 	if (buf[0] == '\0')
276 		gethostname(buf, sizeof(buf));
277 
278 	if (screen_length > 1 || !smart_terminal) {
279 		if (smart_terminal) {
280 			move(0, screen_width - 8 - strlen(buf) - 1);
281 		} else {
282 			if (fputs("    ", stdout) == EOF)
283 				exit(1);
284 		}
285 #ifdef DEBUG
286 		{
287 			char *foo;
288 			foo = ctime(tod);
289 			addstrp(foo);
290 		}
291 #endif
292 		printwp("%s %-8.8s", buf, &(ctime(tod)[11]));
293 		putn();
294 	}
295 }
296 
297 /*
298  *  *_procstates(total, states, threads) - print the process/thread summary line
299  *
300  *  Assumptions:  cursor is at the beginning of the line on entry
301  */
302 void
303 i_procstates(int total, int *states, int threads)
304 {
305 	if (screen_length > 2 || !smart_terminal) {
306 		char procstates_buffer[MAX_COLS];
307 		char uptime[40];
308 
309 		move(1, 0);
310 		clrtoeol();
311 		/* write current number of procs and remember the value */
312 		printwp("%d %s: ", total, threads ? "threads" : "processes");
313 
314 		/* format and print the process state summary */
315 		summary_format(procstates_buffer, sizeof(procstates_buffer),
316 		    states, procstate_names);
317 
318 		addstrp(procstates_buffer);
319 
320 		format_uptime(uptime, sizeof(uptime));
321 		if (smart_terminal)
322 			move(1, screen_width - strlen(uptime));
323 		else
324 			printwp("  ");
325 		printwp("%s", uptime);
326 		putn();
327 	}
328 }
329 
330 /*
331  *  *_cpustates(states) - print the cpu state percentages
332  *
333  *  Assumptions:  cursor is on the PREVIOUS line
334  */
335 
336 /* cpustates_tag() calculates the correct tag to use to label the line */
337 
338 static char *
339 cpustates_tag(int cpu)
340 {
341 	if (screen_length > 3 || !smart_terminal) {
342 		static char *tag;
343 		static int cpulen, old_width;
344 		int i;
345 
346 		if (cpulen == 0 && ncpu > 1) {
347 			/* compute length of the cpu string */
348 			for (i = ncpu; i > 0; cpulen++, i /= 10)
349 				continue;
350 		}
351 
352 		if (old_width == screen_width) {
353 			if (ncpu > 1) {
354 				/* just store the cpu number in the tag */
355 				i = tag[3 + cpulen];
356 				snprintf(tag + 3, cpulen + 1, "%.*d", cpulen, cpu);
357 				tag[3 + cpulen] = i;
358 			}
359 		} else {
360 			/*
361 			 * use a long tag if it will fit, otherwise use short one.
362 			 */
363 			free(tag);
364 			if (cpustate_total_length + 10 + cpulen >= screen_width)
365 				i = asprintf(&tag, "CPU%.*d: ", cpulen, cpu);
366 			else
367 				i = asprintf(&tag, "CPU%.*d states: ", cpulen, cpu);
368 			if (i == -1)
369 				tag = NULL;
370 			else
371 				old_width = screen_width;
372 		}
373 		return (tag);
374 	} else
375 		return ("\0");
376 }
377 
378 void
379 i_cpustates(int64_t *ostates, int *online)
380 {
381 	int i, first, cpu, cpu_line;
382 	double value;
383 	int64_t *states;
384 	char **names, *thisname;
385 
386 	if (combine_cpus) {
387 		static double *values;
388 		if (!values) {
389 			values = calloc(num_cpustates, sizeof(*values));
390 			if (!values)
391 				err(1, NULL);
392 		}
393 		memset(values, 0, num_cpustates * sizeof(*values));
394 		for (cpu = 0; cpu < ncpu; cpu++) {
395 			if (!online[cpu])
396 				continue;
397 			names = cpustate_names;
398 			states = ostates + (CPUSTATES * cpu);
399 			i = 0;
400 			while ((thisname = *names++) != NULL) {
401 				if (*thisname != '\0') {
402 					/* retrieve the value and remember it */
403 					values[i++] += *states++;
404 				}
405 			}
406 		}
407 		if (screen_length > 2 || !smart_terminal) {
408 			names = cpustate_names;
409 			i = 0;
410 			first = 0;
411 			move(2, 0);
412 			clrtoeol();
413 			printwp("%-3d CPUs: ", ncpuonline);
414 
415 			while ((thisname = *names++) != NULL) {
416 				if (*thisname != '\0') {
417 					value = values[i++] / ncpuonline;
418 					/* if percentage is >= 1000, print it as 100% */
419 					printwp((value >= 1000 ? "%s%4.0f%% %s" :
420 					    "%s%4.1f%% %s"), first++ == 0 ? "" : ", ",
421 					    value / 10., thisname);
422 				}
423 			}
424 			putn();
425 		}
426 		return;
427 	}
428 	for (cpu = cpu_line = 0; cpu < ncpu; cpu++) {
429 		/* skip if offline */
430 		if (!online[cpu])
431 			continue;
432 
433 		/* now walk thru the names and print the line */
434 		names = cpustate_names;
435 		first = 0;
436 		states = ostates + (CPUSTATES * cpu);
437 
438 		if (screen_length > 2 + cpu_line || !smart_terminal) {
439 			move(2 + cpu_line, 0);
440 			clrtoeol();
441 			addstrp(cpustates_tag(cpu));
442 
443 			while ((thisname = *names++) != NULL) {
444 				if (*thisname != '\0') {
445 					/* retrieve the value and remember it */
446 					value = *states++;
447 
448 					/* if percentage is >= 1000, print it as 100% */
449 					printwp((value >= 1000 ? "%s%4.0f%% %s" :
450 					    "%s%4.1f%% %s"), first++ == 0 ? "" : ", ",
451 					    value / 10., thisname);
452 				}
453 			}
454 			putn();
455 			cpu_line++;
456 		}
457 	}
458 }
459 
460 /*
461  *  *_memory(stats) - print "Memory: " followed by the memory summary string
462  */
463 void
464 i_memory(int *stats)
465 {
466 	if (screen_length > y_mem || !smart_terminal) {
467 		char memory_buffer[MAX_COLS];
468 
469 		move(y_mem, 0);
470 		clrtoeol();
471 		addstrp("Memory: ");
472 
473 		/* format and print the memory summary */
474 		summary_format(memory_buffer, sizeof(memory_buffer), stats,
475 		    memory_names);
476 		addstrp(memory_buffer);
477 		putn();
478 	}
479 }
480 
481 /*
482  *  *_message() - print the next pending message line, or erase the one
483  *                that is there.
484  */
485 
486 /*
487  *  i_message is funny because it gets its message asynchronously (with
488  *	respect to screen updates).
489  */
490 
491 static char     next_msg[MAX_COLS + 5];
492 static int      msgon = 0;
493 
494 void
495 i_message(void)
496 {
497 	move(y_message, 0);
498 	if (next_msg[0] != '\0') {
499 		standoutp();
500 		addstrp(next_msg);
501 		standendp();
502 		clrtoeol();
503 		msgon = TRUE;
504 		next_msg[0] = '\0';
505 	} else if (msgon) {
506 		clrtoeol();
507 		msgon = FALSE;
508 	}
509 }
510 
511 /*
512  *  *_header(text) - print the header for the process area
513  */
514 
515 void
516 i_header(char *text)
517 {
518 	if (header_status && (screen_length > y_header
519               || !smart_terminal)) {
520 		if (!smart_terminal) {
521 			putn();
522 			if (fputs(text, stdout) == EOF)
523 				exit(1);
524 			putn();
525 		} else {
526 			move(y_header, 0);
527 			clrtoeol();
528 			addstrp(text);
529 		}
530 	}
531 }
532 
533 /*
534  *  *_process(line, thisline) - print one process line
535  */
536 
537 void
538 i_process(int line, char *thisline, int hl)
539 {
540 	/* make sure we are on the correct line */
541 	move(y_procs + line, 0);
542 
543 	/* truncate the line to conform to our current screen width */
544 	thisline[display_width] = '\0';
545 
546 	/* write the line out */
547 	if (hl && smart_terminal)
548 		standoutp();
549 	addstrp(thisline);
550 	if (hl && smart_terminal)
551 		standendp();
552 	putn();
553 	clrtoeol();
554 }
555 
556 void
557 u_endscreen(void)
558 {
559 	if (smart_terminal) {
560 		clrtobot();
561 		/* move the cursor to a pleasant place */
562 		move(y_idlecursor, x_idlecursor);
563 	} else {
564 		/*
565 		 * separate this display from the next with some vertical
566 		 * room
567 		 */
568 		if (fputs("\n\n", stdout) == EOF)
569 			exit(1);
570 	}
571 }
572 
573 void
574 display_header(int status)
575 {
576 	header_status = status;
577 }
578 
579 void
580 new_message(int type, const char *msgfmt,...)
581 {
582 	va_list ap;
583 
584 	va_start(ap, msgfmt);
585 	/* first, format the message */
586 	vsnprintf(next_msg, sizeof(next_msg), msgfmt, ap);
587 	va_end(ap);
588 
589 	if (next_msg[0] != '\0') {
590 		/* message there already -- can we clear it? */
591 		/* yes -- write it and clear to end */
592 		if ((type & MT_delayed) == 0) {
593 			move(y_message, 0);
594 			if (type & MT_standout)
595 				standoutp();
596 			addstrp(next_msg);
597 			if (type & MT_standout)
598 				standendp();
599 			clrtoeol();
600 			msgon = TRUE;
601 			next_msg[0] = '\0';
602 			if (smart_terminal)
603 				refresh();
604 		}
605 	}
606 }
607 
608 void
609 clear_message(void)
610 {
611 	move(y_message, 0);
612 	clrtoeol();
613 }
614 
615 
616 static int
617 readlinedumb(char *buffer, int size)
618 {
619 	char *ptr = buffer, ch, cnt = 0, maxcnt = 0;
620 	extern volatile sig_atomic_t leaveflag;
621 	ssize_t len;
622 
623 	/* allow room for null terminator */
624 	size -= 1;
625 
626 	/* read loop */
627 	while ((fflush(stdout), (len = read(STDIN_FILENO, ptr, 1)) > 0)) {
628 
629 		if (len == 0 || leaveflag) {
630 			end_screen();
631 			exit(0);
632 		}
633 
634 		/* newline means we are done */
635 		if ((ch = *ptr) == '\n')
636 			break;
637 
638 		/* handle special editing characters */
639 		if (ch == ch_kill) {
640 			/* return null string */
641 			*buffer = '\0';
642 			putr();
643 			return (-1);
644 		} else if (ch == ch_erase) {
645 			/* erase previous character */
646 			if (cnt <= 0) {
647 				/* none to erase! */
648 				if (putchar('\7') == EOF)
649 					exit(1);
650 			} else {
651 				if (fputs("\b \b", stdout) == EOF)
652 					exit(1);
653 				ptr--;
654 				cnt--;
655 			}
656 		}
657 		/* check for character validity and buffer overflow */
658 		else if (cnt == size || !isprint((unsigned char)ch)) {
659 			/* not legal */
660 			if (putchar('\7') == EOF)
661 				exit(1);
662 		} else {
663 			/* echo it and store it in the buffer */
664 			if (putchar(ch) == EOF)
665 				exit(1);
666 			ptr++;
667 			cnt++;
668 			if (cnt > maxcnt)
669 				maxcnt = cnt;
670 		}
671 	}
672 
673 	/* all done -- null terminate the string */
674 	*ptr = '\0';
675 
676 	/* return either inputted number or string length */
677 	putr();
678 	return (cnt == 0 ? -1 : cnt);
679 }
680 
681 int
682 readline(char *buffer, int size)
683 {
684 	size_t cnt;
685 
686 	/* allow room for null terminator */
687 	size -= 1;
688 
689 	if (smart_terminal) {
690 		int y, x;
691 		getyx(stdscr, y, x);
692 		while (getnstr(buffer, size) == KEY_RESIZE)
693 			move(y, x);
694 	} else
695 		return readlinedumb(buffer, size);
696 
697 	cnt = strlen(buffer);
698 	if (cnt > 0 && buffer[cnt - 1] == '\n')
699 		buffer[cnt - 1] = '\0';
700 	return (cnt == 0 ? -1 : cnt);
701 }
702 
703 /* internal support routines */
704 static int
705 string_count(char **pp)
706 {
707 	int cnt;
708 
709 	cnt = 0;
710 	while (*pp++ != NULL)
711 		cnt++;
712 	return (cnt);
713 }
714 
715 #define	COPYLEFT(to, from)				\
716 	do {						\
717 		len = strlcpy((to), (from), left);	\
718 		if (len >= left)			\
719 			return;				\
720 		p += len;				\
721 		left -= len;				\
722 	} while (0)
723 
724 static void
725 summary_format(char *buf, size_t left, int *numbers, char **names)
726 {
727 	char *p, *thisname;
728 	int len;
729 	int num;
730 
731 	/* format each number followed by its string */
732 	p = buf;
733 	while ((thisname = *names++) != NULL) {
734 		/* get the number to format */
735 		num = *numbers++;
736 
737 		if (num >= 0) {
738 			/* is this number in kilobytes? */
739 			if (thisname[0] == 'K') {
740 				/* yes: format it as a memory value */
741 				COPYLEFT(p, format_k(num));
742 
743 				/*
744 				 * skip over the K, since it was included by
745 				 * format_k
746 				 */
747 				COPYLEFT(p, thisname + 1);
748 			} else if (num > 0) {
749 				len = snprintf(p, left, "%d%s", num, thisname);
750 				if (len < 0 || len >= left)
751 					return;
752 				p += len;
753 				left -= len;
754 			}
755 		} else {
756 			/*
757 			 * Ignore negative numbers, but display corresponding
758 			 * string.
759 			 */
760 			COPYLEFT(p, thisname);
761 		}
762 	}
763 
764 	/* if the last two characters in the string are ", ", delete them */
765 	p -= 2;
766 	if (p >= buf && p[0] == ',' && p[1] == ' ')
767 		*p = '\0';
768 }
769 
770 /*
771  *  printable(str) - make the string pointed to by "str" into one that is
772  *	printable (i.e.: all ascii), by converting all non-printable
773  *	characters into '?'.  Replacements are done in place and a pointer
774  *	to the original buffer is returned.
775  */
776 char *
777 printable(char *str)
778 {
779 	char *ptr, ch;
780 
781 	ptr = str;
782 	while ((ch = *ptr) != '\0') {
783 		if (!isprint((unsigned char)ch))
784 			*ptr = '?';
785 		ptr++;
786 	}
787 	return (str);
788 }
789 
790 
791 /*
792  *  show_help() - display the help screen; invoked in response to
793  *		either 'h' or '?'.
794  */
795 void
796 show_help(void)
797 {
798 	if (smart_terminal) {
799 		clear();
800 		nl();
801 	}
802 	printwp("These single-character commands are available:\n"
803 	    "\n"
804 	    "^L           - redraw screen\n"
805 	    "<space>      - update screen\n"
806 	    "+            - reset any P highlight, g, p, or u filters\n"
807 	    "1            - display CPU statistics on a single line\n"
808 	    "9 | 0        - scroll up/down the process list by one line\n"
809 	    "( | )        - scroll up/down the process list by screen half\n"
810 	    "C            - toggle the display of command line arguments\n"
811 	    "d count      - show `count' displays, then exit\n"
812 	    "e            - list errors generated by last \"kill\" or \"renice\" command\n"
813 	    "g|/ string   - filter on command name (g+ or /+ selects all commands)\n"
814 	    "h | ?        - help; show this text\n"
815 	    "H            - toggle the display of threads\n"
816 	    "I | i        - toggle the display of idle processes\n"
817 	    "k [-sig] pid - send signal `-sig' (TERM by default) to process `pid'\n"
818 	    "n|# count    - show `count' processes\n"
819 	    "o [-]field   - specify sort order (size, res, cpu, time, pri, pid, command)\n"
820 	    "               (o -field sorts in reverse)\n"
821 	    "P pid        - highlight process `pid' (P+ switches highlighting off)\n"
822 	    "p pid        - display process by `pid' (p+ selects all processes)\n"
823 	    "q            - quit\n"
824 	    "r count pid  - renice process `pid' to nice value `count'\n"
825 	    "S            - toggle the display of system processes\n"
826 	    "s time       - change delay between displays to `time' seconds\n"
827 	    "u [-]user    - show processes for `user' (u+ shows all, u -user hides user)\n"
828 	    "\n");
829 
830 	if (smart_terminal) {
831 		nonl();
832 		refresh();
833 	}
834 }
835 
836 /*
837  *  show_errors() - display on stdout the current log of errors.
838  */
839 void
840 show_errors(void)
841 {
842 	struct errs *errp = errs;
843 	int cnt = 0;
844 
845 	if (smart_terminal) {
846 		clear();
847 		nl();
848 	}
849 	printwp("%d error%s:\n\n", errcnt, errcnt == 1 ? "" : "s");
850 	while (cnt++ < errcnt) {
851 		printwp("%5s: %s\n", errp->arg,
852 		    errp->err == 0 ? "Not a number" : strerror(errp->err));
853 		errp++;
854 	}
855 	printwp("\n");
856 	if (smart_terminal) {
857 		nonl();
858 		refresh();
859 	}
860 }
861 
862 void
863 anykey(void)
864 {
865 	int ch;
866 	ssize_t len;
867 
868 	standoutp();
869 	addstrp("Hit any key to continue: ");
870 	standendp();
871 	if (smart_terminal)
872 		refresh();
873 	else
874 		fflush(stdout);
875 	while (1) {
876 		len = read(STDIN_FILENO, &ch, 1);
877 		if (len == -1 && errno == EINTR)
878 			continue;
879 		if (len == 0)
880 			exit(1);
881 		break;
882 	}
883 }
884