1/* vi: set sw=4 ts=4: */
2/*
3 * A tiny 'top' utility.
4 *
5 * This is written specifically for the linux /proc/<PID>/stat(m)
6 * files format.
7
8 * This reads the PIDs of all processes and their status and shows
9 * the status of processes (first ones that fit to screen) at given
10 * intervals.
11 *
12 * NOTES:
13 * - At startup this changes to /proc, all the reads are then
14 *   relative to that.
15 *
16 * (C) Eero Tamminen <oak at welho dot com>
17 *
18 * Rewritten by Vladimir Oleynik (C) 2002 <dzo@simtreas.ru>
19 */
20
21/* Original code Copyrights */
22/*
23 * Copyright (c) 1992 Branko Lankester
24 * Copyright (c) 1992 Roger Binns
25 * Copyright (C) 1994-1996 Charles L. Blake.
26 * Copyright (C) 1992-1998 Michael K. Johnson
27 * May be distributed under the conditions of the
28 * GNU Library General Public License
29 */
30
31#include "libbb.h"
32
33
34typedef struct top_status_t {
35	unsigned long vsz;
36#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
37	unsigned long ticks;
38	unsigned pcpu; /* delta of ticks */
39#endif
40	unsigned pid, ppid;
41	unsigned uid;
42	char state[4];
43	char comm[COMM_LEN];
44} top_status_t;
45
46typedef struct jiffy_counts_t {
47	unsigned long long usr,nic,sys,idle,iowait,irq,softirq,steal;
48	unsigned long long total;
49	unsigned long long busy;
50} jiffy_counts_t;
51
52/* This structure stores some critical information from one frame to
53   the next. Used for finding deltas. */
54typedef struct save_hist {
55	unsigned long ticks;
56	unsigned pid;
57} save_hist;
58
59typedef int (*cmp_funcp)(top_status_t *P, top_status_t *Q);
60
61enum { SORT_DEPTH = 3 };
62
63struct globals {
64	top_status_t *top;
65	int ntop;
66#if ENABLE_FEATURE_USE_TERMIOS
67	struct termios initial_settings;
68#endif
69#if !ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
70	cmp_funcp sort_function;
71#else
72	cmp_funcp sort_function[SORT_DEPTH];
73	struct save_hist *prev_hist;
74	int prev_hist_count;
75	jiffy_counts_t jif, prev_jif;
76	/* int hist_iterations; */
77	unsigned total_pcpu;
78	/* unsigned long total_vsz; */
79#endif
80};
81#define G (*(struct globals*)&bb_common_bufsiz1)
82#define top              (G.top               )
83#define ntop             (G.ntop              )
84#if ENABLE_FEATURE_USE_TERMIOS
85#define initial_settings (G. initial_settings )
86#endif
87#define sort_function    (G.sort_function     )
88#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
89#define prev_hist        (G.prev_hist         )
90#define prev_hist_count  (G.prev_hist_count   )
91#define jif              (G.jif               )
92#define prev_jif         (G.prev_jif          )
93#define total_pcpu       (G.total_pcpu        )
94#endif
95
96#define OPT_BATCH_MODE (option_mask32 & 0x4)
97
98
99#if ENABLE_FEATURE_USE_TERMIOS
100static int pid_sort(top_status_t *P, top_status_t *Q)
101{
102	/* Buggy wrt pids with high bit set */
103	/* (linux pids are in [1..2^15-1]) */
104	return (Q->pid - P->pid);
105}
106#endif
107
108static int mem_sort(top_status_t *P, top_status_t *Q)
109{
110	/* We want to avoid unsigned->signed and truncation errors */
111	if (Q->vsz < P->vsz) return -1;
112	return Q->vsz != P->vsz; /* 0 if ==, 1 if > */
113}
114
115
116#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
117
118static int pcpu_sort(top_status_t *P, top_status_t *Q)
119{
120	/* Buggy wrt ticks with high bit set */
121	/* Affects only processes for which ticks overflow */
122	return (int)Q->pcpu - (int)P->pcpu;
123}
124
125static int time_sort(top_status_t *P, top_status_t *Q)
126{
127	/* We want to avoid unsigned->signed and truncation errors */
128	if (Q->ticks < P->ticks) return -1;
129	return Q->ticks != P->ticks; /* 0 if ==, 1 if > */
130}
131
132static int mult_lvl_cmp(void* a, void* b)
133{
134	int i, cmp_val;
135
136	for (i = 0; i < SORT_DEPTH; i++) {
137		cmp_val = (*sort_function[i])(a, b);
138		if (cmp_val != 0)
139			return cmp_val;
140	}
141	return 0;
142}
143
144
145static void get_jiffy_counts(void)
146{
147	FILE* fp = xfopen("stat", "r");
148	prev_jif = jif;
149	if (fscanf(fp, "cpu  %lld %lld %lld %lld %lld %lld %lld %lld",
150			&jif.usr,&jif.nic,&jif.sys,&jif.idle,
151			&jif.iowait,&jif.irq,&jif.softirq,&jif.steal) < 4) {
152		bb_error_msg_and_die("failed to read /proc/stat");
153	}
154	fclose(fp);
155	jif.total = jif.usr + jif.nic + jif.sys + jif.idle
156			+ jif.iowait + jif.irq + jif.softirq + jif.steal;
157	/* procps 2.x does not count iowait as busy time */
158	jif.busy = jif.total - jif.idle - jif.iowait;
159}
160
161
162static void do_stats(void)
163{
164	top_status_t *cur;
165	pid_t pid;
166	int i, last_i, n;
167	struct save_hist *new_hist;
168
169	get_jiffy_counts();
170	total_pcpu = 0;
171	/* total_vsz = 0; */
172	new_hist = xmalloc(sizeof(struct save_hist)*ntop);
173	/*
174	 * Make a pass through the data to get stats.
175	 */
176	/* hist_iterations = 0; */
177	i = 0;
178	for (n = 0; n < ntop; n++) {
179		cur = top + n;
180
181		/*
182		 * Calculate time in cur process.  Time is sum of user time
183		 * and system time
184		 */
185		pid = cur->pid;
186		new_hist[n].ticks = cur->ticks;
187		new_hist[n].pid = pid;
188
189		/* find matching entry from previous pass */
190		cur->pcpu = 0;
191		/* do not start at index 0, continue at last used one
192		 * (brought hist_iterations from ~14000 down to 172) */
193		last_i = i;
194		if (prev_hist_count) do {
195			if (prev_hist[i].pid == pid) {
196				cur->pcpu = cur->ticks - prev_hist[i].ticks;
197				total_pcpu += cur->pcpu;
198				break;
199			}
200			i = (i+1) % prev_hist_count;
201			/* hist_iterations++; */
202		} while (i != last_i);
203		/* total_vsz += cur->vsz; */
204	}
205
206	/*
207	 * Save cur frame's information.
208	 */
209	free(prev_hist);
210	prev_hist = new_hist;
211	prev_hist_count = ntop;
212}
213#endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */
214
215#if ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS && ENABLE_FEATURE_TOP_DECIMALS
216/* formats 7 char string (8 with terminating NUL) */
217static char *fmt_100percent_8(char pbuf[8], unsigned value, unsigned total)
218{
219	unsigned t;
220	if (value >= total) { /* 100% ? */
221		strcpy(pbuf, "  100% ");
222		return pbuf;
223	}
224	/* else generate " [N/space]N.N% " string */
225	value = 1000 * value / total;
226	t = value / 100;
227	value = value % 100;
228	pbuf[0] = ' ';
229	pbuf[1] = t ? t + '0' : ' ';
230	pbuf[2] = '0' + (value / 10);
231	pbuf[3] = '.';
232	pbuf[4] = '0' + (value % 10);
233	pbuf[5] = '%';
234	pbuf[6] = ' ';
235	pbuf[7] = '\0';
236	return pbuf;
237}
238#endif
239
240/* display generic info (meminfo / loadavg) */
241static unsigned long display_generic(int scr_width)
242{
243	FILE *fp;
244	char buf[80];
245	char scrbuf[80];
246	unsigned long total, used, mfree, shared, buffers, cached;
247#if ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS
248	unsigned total_diff;
249#endif
250
251	/* read memory info */
252	fp = xfopen("meminfo", "r");
253
254	/*
255	 * Old kernels (such as 2.4.x) had a nice summary of memory info that
256	 * we could parse, however this is gone entirely in 2.6. Try parsing
257	 * the old way first, and if that fails, parse each field manually.
258	 *
259	 * First, we read in the first line. Old kernels will have bogus
260	 * strings we don't care about, whereas new kernels will start right
261	 * out with MemTotal:
262	 *                              -- PFM.
263	 */
264	if (fscanf(fp, "MemTotal: %lu %s\n", &total, buf) != 2) {
265		fgets(buf, sizeof(buf), fp);    /* skip first line */
266
267		fscanf(fp, "Mem: %lu %lu %lu %lu %lu %lu",
268			&total, &used, &mfree, &shared, &buffers, &cached);
269		/* convert to kilobytes */
270		used /= 1024;
271		mfree /= 1024;
272		shared /= 1024;
273		buffers /= 1024;
274		cached /= 1024;
275		total /= 1024;
276	} else {
277		/*
278		 * Revert to manual parsing, which incidentally already has the
279		 * sizes in kilobytes. This should be safe for both 2.4 and
280		 * 2.6.
281		 */
282
283		fscanf(fp, "MemFree: %lu %s\n", &mfree, buf);
284
285		/*
286		 * MemShared: is no longer present in 2.6. Report this as 0,
287		 * to maintain consistent behavior with normal procps.
288		 */
289		if (fscanf(fp, "MemShared: %lu %s\n", &shared, buf) != 2)
290			shared = 0;
291
292		fscanf(fp, "Buffers: %lu %s\n", &buffers, buf);
293		fscanf(fp, "Cached: %lu %s\n", &cached, buf);
294
295		used = total - mfree;
296	}
297	fclose(fp);
298
299	/* output memory info */
300	if (scr_width > sizeof(scrbuf))
301		scr_width = sizeof(scrbuf);
302	snprintf(scrbuf, scr_width,
303		"Mem: %luK used, %luK free, %luK shrd, %luK buff, %luK cached",
304		used, mfree, shared, buffers, cached);
305	/* clear screen & go to top */
306	printf(OPT_BATCH_MODE ? "%s\n" : "\e[H\e[J%s\n", scrbuf);
307
308#if ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS
309	/* using (unsigned) casts to make operations cheaper */
310	total_diff = ((unsigned)(jif.total - prev_jif.total) ? : 1);
311#if ENABLE_FEATURE_TOP_DECIMALS
312/* Generated code is approx +0.3k */
313#define CALC_STAT(xxx) char xxx[8]
314#define SHOW_STAT(xxx) fmt_100percent_8(xxx, (unsigned)(jif.xxx - prev_jif.xxx), total_diff)
315#define FMT "%s"
316#else
317#define CALC_STAT(xxx) unsigned xxx = 100 * (unsigned)(jif.xxx - prev_jif.xxx) / total_diff
318#define SHOW_STAT(xxx) xxx
319#define FMT "%4u%% "
320#endif
321	{ /* need block: CALC_STAT are declarations */
322		CALC_STAT(usr);
323		CALC_STAT(sys);
324		CALC_STAT(nic);
325		CALC_STAT(idle);
326		CALC_STAT(iowait);
327		CALC_STAT(irq);
328		CALC_STAT(softirq);
329		//CALC_STAT(steal);
330
331		snprintf(scrbuf, scr_width,
332			/* Barely fits in 79 chars when in "decimals" mode. */
333			"CPU:"FMT"usr"FMT"sys"FMT"nice"FMT"idle"FMT"io"FMT"irq"FMT"softirq",
334			SHOW_STAT(usr), SHOW_STAT(sys), SHOW_STAT(nic), SHOW_STAT(idle),
335			SHOW_STAT(iowait), SHOW_STAT(irq), SHOW_STAT(softirq)
336			//, SHOW_STAT(steal) - what is this 'steal' thing?
337			// I doubt anyone wants to know it
338		);
339	}
340	puts(scrbuf);
341#undef SHOW_STAT
342#undef CALC_STAT
343#undef FMT
344#endif
345
346	/* read load average as a string */
347	buf[0] = '\0';
348	open_read_close("loadavg", buf, sizeof("N.NN N.NN N.NN")-1);
349	buf[sizeof("N.NN N.NN N.NN")-1] = '\0';
350	snprintf(scrbuf, scr_width, "Load average: %s", buf);
351	puts(scrbuf);
352
353	return total;
354}
355
356/* display process statuses */
357static void display_status(int count, int scr_width)
358{
359	enum {
360		BITS_PER_INT = sizeof(int)*8
361	};
362
363	top_status_t *s = top;
364	char vsz_str_buf[8];
365	unsigned long total_memory = display_generic(scr_width); /* or use total_vsz? */
366	/* xxx_shift and xxx_scale variables allow us to replace
367	 * expensive divides with multiply and shift */
368	unsigned pmem_shift, pmem_scale, pmem_half;
369#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
370	unsigned pcpu_shift, pcpu_scale, pcpu_half;
371	unsigned busy_jifs;
372
373	/* what info of the processes is shown */
374	printf(OPT_BATCH_MODE ? "%.*s" : "\e[7m%.*s\e[0m", scr_width,
375		"  PID  PPID USER     STAT   VSZ %MEM %CPU COMMAND");
376#define MIN_WIDTH \
377	sizeof( "  PID  PPID USER     STAT   VSZ %MEM %CPU C")
378#else
379
380	/* !CPU_USAGE_PERCENTAGE */
381	printf(OPT_BATCH_MODE ? "%.*s" : "\e[7m%.*s\e[0m", scr_width,
382		"  PID  PPID USER     STAT   VSZ %MEM COMMAND");
383#define MIN_WIDTH \
384	sizeof( "  PID  PPID USER     STAT   VSZ %MEM C")
385#endif
386
387#if ENABLE_FEATURE_TOP_DECIMALS
388#define UPSCALE 1000
389#define CALC_STAT(name, val) div_t name = div((val), 10)
390#define SHOW_STAT(name) name.quot, '0'+name.rem
391#define FMT "%3u.%c"
392#else
393#define UPSCALE 100
394#define CALC_STAT(name, val) unsigned name = (val)
395#define SHOW_STAT(name) name
396#define FMT "%4u%%"
397#endif
398	/*
399	 * MEM% = s->vsz/MemTotal
400	 */
401	pmem_shift = BITS_PER_INT-11;
402	pmem_scale = UPSCALE*(1U<<(BITS_PER_INT-11)) / total_memory;
403	/* s->vsz is in kb. we want (s->vsz * pmem_scale) to never overflow */
404	while (pmem_scale >= 512) {
405		pmem_scale /= 4;
406		pmem_shift -= 2;
407	}
408	pmem_half = (1U << pmem_shift) / (ENABLE_FEATURE_TOP_DECIMALS? 20 : 2);
409#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
410	busy_jifs = jif.busy - prev_jif.busy;
411	/* This happens if there were lots of short-lived processes
412	 * between two top updates (e.g. compilation) */
413	if (total_pcpu < busy_jifs) total_pcpu = busy_jifs;
414
415	/*
416	 * CPU% = s->pcpu/sum(s->pcpu) * busy_cpu_ticks/total_cpu_ticks
417	 * (pcpu is delta of sys+user time between samples)
418	 */
419	pcpu_shift = 6;
420	pcpu_scale = (UPSCALE*64*(uint16_t)busy_jifs ? : 1);
421	while (pcpu_scale < (1U<<(BITS_PER_INT-2))) {
422		pcpu_scale *= 4;
423		pcpu_shift += 2;
424	}
425	pcpu_scale /= ( (uint16_t)(jif.total-prev_jif.total)*total_pcpu ? : 1);
426	/* we want (s->pcpu * pcpu_scale) to never overflow */
427	while (pcpu_scale >= 1024) {
428		pcpu_scale /= 4;
429		pcpu_shift -= 2;
430	}
431	pcpu_half = (1U << pcpu_shift) / (ENABLE_FEATURE_TOP_DECIMALS? 20 : 2);
432	/* printf(" pmem_scale=%u pcpu_scale=%u ", pmem_scale, pcpu_scale); */
433#endif
434
435	/* Ok, all prelim data is ready, go thru the list */
436	while (count-- > 0) {
437		int col = scr_width;
438		CALC_STAT(pmem, (s->vsz*pmem_scale + pmem_half) >> pmem_shift);
439#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
440		CALC_STAT(pcpu, (s->pcpu*pcpu_scale + pcpu_half) >> pcpu_shift);
441#endif
442
443		if (s->vsz >= 100*1024)
444			sprintf(vsz_str_buf, "%6ldM", s->vsz/1024);
445		else
446			sprintf(vsz_str_buf, "%7ld", s->vsz);
447		// PID PPID USER STAT VSZ %MEM [%CPU] COMMAND
448		col -= printf("\n" "%5u%6u %-8.8s %s%s" FMT
449#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
450				FMT
451#endif
452				" ",
453				s->pid, s->ppid, get_cached_username(s->uid),
454				s->state, vsz_str_buf,
455				SHOW_STAT(pmem)
456#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
457				, SHOW_STAT(pcpu)
458#endif
459		);
460		if (col > 0) {
461			char buf[col + 1];
462			read_cmdline(buf, col, s->pid, s->comm);
463			fputs(buf, stdout);
464		}
465		/* printf(" %d/%d %lld/%lld", s->pcpu, total_pcpu,
466			jif.busy - prev_jif.busy, jif.total - prev_jif.total); */
467		s++;
468	}
469	/* printf(" %d", hist_iterations); */
470	putchar(OPT_BATCH_MODE ? '\n' : '\r');
471	fflush(stdout);
472}
473#undef UPSCALE
474#undef SHOW_STAT
475#undef CALC_STAT
476#undef FMT
477
478
479static void clearmems(void)
480{
481	clear_username_cache();
482	free(top);
483	top = 0;
484	ntop = 0;
485}
486
487
488#if ENABLE_FEATURE_USE_TERMIOS
489#include <termios.h>
490#include <signal.h>
491
492static void reset_term(void)
493{
494	tcsetattr(0, TCSANOW, (void *) &initial_settings);
495#if ENABLE_FEATURE_CLEAN_UP
496	clearmems();
497#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
498	free(prev_hist);
499#endif
500#endif /* FEATURE_CLEAN_UP */
501}
502
503static void sig_catcher(int sig ATTRIBUTE_UNUSED)
504{
505	reset_term();
506	exit(1);
507}
508#endif /* FEATURE_USE_TERMIOS */
509
510
511int top_main(int argc, char **argv);
512int top_main(int argc, char **argv)
513{
514	int count, lines, col;
515	unsigned interval = 5; /* default update rate is 5 seconds */
516	unsigned iterations = UINT_MAX; /* 2^32 iterations by default :) */
517	char *sinterval, *siterations;
518#if ENABLE_FEATURE_USE_TERMIOS
519	struct termios new_settings;
520	struct timeval tv;
521	fd_set readfds;
522	unsigned char c;
523#endif /* FEATURE_USE_TERMIOS */
524
525	interval = 5;
526
527	/* do normal option parsing */
528	opt_complementary = "-";
529	getopt32(argv, "d:n:b", &sinterval, &siterations);
530	if (option_mask32 & 0x1) interval = xatou(sinterval); // -d
531	if (option_mask32 & 0x2) iterations = xatou(siterations); // -n
532	//if (option_mask32 & 0x4) // -b
533
534	/* change to /proc */
535	xchdir("/proc");
536#if ENABLE_FEATURE_USE_TERMIOS
537	tcgetattr(0, (void *) &initial_settings);
538	memcpy(&new_settings, &initial_settings, sizeof(struct termios));
539	/* unbuffered input, turn off echo */
540	new_settings.c_lflag &= ~(ISIG | ICANON | ECHO | ECHONL);
541
542	signal(SIGTERM, sig_catcher);
543	signal(SIGINT, sig_catcher);
544	tcsetattr(0, TCSANOW, (void *) &new_settings);
545	atexit(reset_term);
546#endif /* FEATURE_USE_TERMIOS */
547
548#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
549	sort_function[0] = pcpu_sort;
550	sort_function[1] = mem_sort;
551	sort_function[2] = time_sort;
552#else
553	sort_function = mem_sort;
554#endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */
555
556	while (1) {
557		procps_status_t *p = NULL;
558
559		/* Default to 25 lines - 5 lines for status */
560		lines = 24 - 3 USE_FEATURE_TOP_CPU_GLOBAL_PERCENTS( - 1);
561		col = 79;
562#if ENABLE_FEATURE_USE_TERMIOS
563		get_terminal_width_height(0, &col, &lines);
564		if (lines < 5 || col < MIN_WIDTH) {
565			sleep(interval);
566			continue;
567		}
568		lines -= 3 USE_FEATURE_TOP_CPU_GLOBAL_PERCENTS( + 1);
569#endif /* FEATURE_USE_TERMIOS */
570
571		/* read process IDs & status for all the processes */
572		while ((p = procps_scan(p, 0
573				| PSSCAN_PID
574				| PSSCAN_PPID
575				| PSSCAN_VSZ
576				| PSSCAN_STIME
577				| PSSCAN_UTIME
578				| PSSCAN_STATE
579				| PSSCAN_COMM
580				| PSSCAN_SID
581				| PSSCAN_UIDGID
582		))) {
583			int n = ntop;
584			top = xrealloc(top, (++ntop) * sizeof(*top));
585			top[n].pid = p->pid;
586			top[n].ppid = p->ppid;
587			top[n].vsz = p->vsz;
588#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
589			top[n].ticks = p->stime + p->utime;
590#endif
591			top[n].uid = p->uid;
592			strcpy(top[n].state, p->state);
593			strcpy(top[n].comm, p->comm);
594		}
595		if (ntop == 0) {
596			bb_error_msg_and_die("no process info in /proc");
597		}
598#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
599		if (!prev_hist_count) {
600			do_stats();
601			sleep(1);
602			clearmems();
603			continue;
604		}
605		do_stats();
606/* TODO: we don't need to sort all 10000 processes, we need to find top 24! */
607		qsort(top, ntop, sizeof(top_status_t), (void*)mult_lvl_cmp);
608#else
609		qsort(top, ntop, sizeof(top_status_t), (void*)sort_function);
610#endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */
611		count = lines;
612		if (OPT_BATCH_MODE || count > ntop) {
613			count = ntop;
614		}
615		/* show status for each of the processes */
616		display_status(count, col);
617#if ENABLE_FEATURE_USE_TERMIOS
618		tv.tv_sec = interval;
619		tv.tv_usec = 0;
620		FD_ZERO(&readfds);
621		FD_SET(0, &readfds);
622		select(1, &readfds, NULL, NULL, &tv);
623		if (FD_ISSET(0, &readfds)) {
624			if (read(0, &c, 1) <= 0) {   /* signal */
625				return EXIT_FAILURE;
626			}
627			if (c == 'q' || c == initial_settings.c_cc[VINTR])
628				break;
629			if (c == 'M') {
630#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
631				sort_function[0] = mem_sort;
632				sort_function[1] = pcpu_sort;
633				sort_function[2] = time_sort;
634#else
635				sort_function = mem_sort;
636#endif
637			}
638#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
639			if (c == 'P') {
640				sort_function[0] = pcpu_sort;
641				sort_function[1] = mem_sort;
642				sort_function[2] = time_sort;
643			}
644			if (c == 'T') {
645				sort_function[0] = time_sort;
646				sort_function[1] = mem_sort;
647				sort_function[2] = pcpu_sort;
648			}
649#endif
650			if (c == 'N') {
651#if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
652				sort_function[0] = pid_sort;
653#else
654				sort_function = pid_sort;
655#endif
656			}
657		}
658		if (!--iterations)
659			break;
660#else
661		sleep(interval);
662#endif /* FEATURE_USE_TERMIOS */
663		clearmems();
664	}
665	if (ENABLE_FEATURE_CLEAN_UP)
666		clearmems();
667	putchar('\n');
668	return EXIT_SUCCESS;
669}
670