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  * Sept 2008: Vineet Gupta <vineet.gupta@arc.com>
21  * Added Support for reporting SMP Information
22  * - CPU where process was last seen running
23  *   (to see effect of sched_setaffinity() etc)
24  * - CPU time split (idle/IO/wait etc) per CPU
25  *
26  * Copyright (c) 1992 Branko Lankester
27  * Copyright (c) 1992 Roger Binns
28  * Copyright (C) 1994-1996 Charles L. Blake.
29  * Copyright (C) 1992-1998 Michael K. Johnson
30  *
31  * Licensed under GPLv2, see file LICENSE in this source tree.
32  */
33 /* How to snapshot /proc for debugging top problems:
34  * for f in /proc/[0-9]*""/stat; do
35  *         n=${f#/proc/}
36  *         n=${n%/stat}_stat
37  *         cp $f $n
38  * done
39  * cp /proc/stat /proc/meminfo /proc/loadavg .
40  * top -bn1 >top.out
41  *
42  * ...and how to run top on it on another machine:
43  * rm -rf proc; mkdir proc
44  * for f in [0-9]*_stat; do
45  *         p=${f%_stat}
46  *         mkdir -p proc/$p
47  *         cp $f proc/$p/stat
48  * done
49  * cp stat meminfo loadavg proc
50  * chroot . ./top -bn1 >top1.out
51  */
52 //config:config TOP
53 //config:	bool "top (18 kb)"
54 //config:	default y
55 //config:	help
56 //config:	The top program provides a dynamic real-time view of a running
57 //config:	system.
58 //config:
59 //config:config FEATURE_TOP_INTERACTIVE
60 //config:	bool "Accept keyboard commands"
61 //config:	default y
62 //config:	depends on TOP
63 //config:	help
64 //config:	Without this, top will only refresh display every 5 seconds.
65 //config:	No keyboard commands will work, only ^C to terminate.
66 //config:
67 //config:config FEATURE_TOP_CPU_USAGE_PERCENTAGE
68 //config:	bool "Show CPU per-process usage percentage"
69 //config:	default y
70 //config:	depends on TOP
71 //config:	help
72 //config:	Make top display CPU usage for each process.
73 //config:	This adds about 2k.
74 //config:
75 //config:config FEATURE_TOP_CPU_GLOBAL_PERCENTS
76 //config:	bool "Show CPU global usage percentage"
77 //config:	default y
78 //config:	depends on FEATURE_TOP_CPU_USAGE_PERCENTAGE
79 //config:	help
80 //config:	Makes top display "CPU: NN% usr NN% sys..." line.
81 //config:	This adds about 0.5k.
82 //config:
83 //config:config FEATURE_TOP_SMP_CPU
84 //config:	bool "SMP CPU usage display ('c' key)"
85 //config:	default y
86 //config:	depends on FEATURE_TOP_CPU_GLOBAL_PERCENTS
87 //config:	help
88 //config:	Allow 'c' key to switch between individual/cumulative CPU stats
89 //config:	This adds about 0.5k.
90 //config:
91 //config:config FEATURE_TOP_DECIMALS
92 //config:	bool "Show 1/10th of a percent in CPU/mem statistics"
93 //config:	default y
94 //config:	depends on FEATURE_TOP_CPU_USAGE_PERCENTAGE
95 //config:	help
96 //config:	Show 1/10th of a percent in CPU/mem statistics.
97 //config:	This adds about 0.3k.
98 //config:
99 //config:config FEATURE_TOP_SMP_PROCESS
100 //config:	bool "Show CPU process runs on ('j' field)"
101 //config:	default y
102 //config:	depends on TOP
103 //config:	help
104 //config:	Show CPU where process was last found running on.
105 //config:	This is the 'j' field.
106 //config:
107 //config:config FEATURE_TOPMEM
108 //config:	bool "Topmem command ('s' key)"
109 //config:	default y
110 //config:	depends on TOP
111 //config:	help
112 //config:	Enable 's' in top (gives lots of memory info).
113 
114 //applet:IF_TOP(APPLET(top, BB_DIR_USR_BIN, BB_SUID_DROP))
115 
116 //kbuild:lib-$(CONFIG_TOP) += top.o
117 
118 #include "libbb.h"
119 
120 #define ESC "\033"
121 
122 typedef struct top_status_t {
123 	unsigned long vsz;
124 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
125 	unsigned long ticks;
126 	unsigned pcpu; /* delta of ticks */
127 #endif
128 	unsigned pid, ppid;
129 	unsigned uid;
130 	char state[4];
131 	char comm[COMM_LEN];
132 #if ENABLE_FEATURE_TOP_SMP_PROCESS
133 	int last_seen_on_cpu;
134 #endif
135 } top_status_t;
136 
137 typedef struct jiffy_counts_t {
138 	/* Linux 2.4.x has only first four */
139 	unsigned long long usr, nic, sys, idle;
140 	unsigned long long iowait, irq, softirq, steal;
141 	unsigned long long total;
142 	unsigned long long busy;
143 } jiffy_counts_t;
144 
145 /* This structure stores some critical information from one frame to
146    the next. Used for finding deltas. */
147 typedef struct save_hist {
148 	unsigned long ticks;
149 	pid_t pid;
150 } save_hist;
151 
152 typedef int (*cmp_funcp)(top_status_t *P, top_status_t *Q);
153 
154 
155 enum { SORT_DEPTH = 3 };
156 
157 /* Screens wider than this are unlikely */
158 enum { LINE_BUF_SIZE = 512 - 64 };
159 
160 struct globals {
161 	top_status_t *top;
162 	int ntop;
163 	smallint inverted;
164 #if ENABLE_FEATURE_TOPMEM
165 	smallint sort_field;
166 #endif
167 #if ENABLE_FEATURE_TOP_SMP_CPU
168 	smallint smp_cpu_info; /* one/many cpu info lines? */
169 #endif
170 	unsigned lines;  /* screen height */
171 #if ENABLE_FEATURE_TOP_INTERACTIVE
172 	struct termios initial_settings;
173 	int scroll_ofs;
174 #define G_scroll_ofs G.scroll_ofs
175 #else
176 #define G_scroll_ofs 0
177 #endif
178 #if !ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
179 	cmp_funcp sort_function[1];
180 #else
181 	cmp_funcp sort_function[SORT_DEPTH];
182 	struct save_hist *prev_hist;
183 	unsigned prev_hist_count;
184 	jiffy_counts_t cur_jif, prev_jif;
185 	/* int hist_iterations; */
186 	unsigned total_pcpu;
187 	/* unsigned long total_vsz; */
188 #endif
189 #if ENABLE_FEATURE_TOP_SMP_CPU
190 	/* Per CPU samples: current and last */
191 	jiffy_counts_t *cpu_jif, *cpu_prev_jif;
192 	unsigned num_cpus;
193 #endif
194 #if ENABLE_FEATURE_TOP_INTERACTIVE
195 	char kbd_input[KEYCODE_BUFFER_SIZE];
196 #endif
197 	char line_buf[LINE_BUF_SIZE];
198 };
199 #define G (*ptr_to_globals)
200 #define top              (G.top               )
201 #define ntop             (G.ntop              )
202 #define sort_field       (G.sort_field        )
203 #define inverted         (G.inverted          )
204 #define smp_cpu_info     (G.smp_cpu_info      )
205 #define initial_settings (G.initial_settings  )
206 #define sort_function    (G.sort_function     )
207 #define prev_hist        (G.prev_hist         )
208 #define prev_hist_count  (G.prev_hist_count   )
209 #define cur_jif          (G.cur_jif           )
210 #define prev_jif         (G.prev_jif          )
211 #define cpu_jif          (G.cpu_jif           )
212 #define cpu_prev_jif     (G.cpu_prev_jif      )
213 #define num_cpus         (G.num_cpus          )
214 #define total_pcpu       (G.total_pcpu        )
215 #define line_buf         (G.line_buf          )
216 #define INIT_G() do { \
217 	SET_PTR_TO_GLOBALS(xzalloc(sizeof(G))); \
218 	BUILD_BUG_ON(LINE_BUF_SIZE <= 80); \
219 } while (0)
220 
221 enum {
222 	OPT_d = (1 << 0),
223 	OPT_n = (1 << 1),
224 	OPT_b = (1 << 2),
225 	OPT_H = (1 << 3),
226 	OPT_m = (1 << 4),
227 	OPT_EOF = (1 << 5), /* pseudo: "we saw EOF in stdin" */
228 };
229 #define OPT_BATCH_MODE (option_mask32 & OPT_b)
230 
231 
232 #if ENABLE_FEATURE_TOP_INTERACTIVE
pid_sort(top_status_t * P,top_status_t * Q)233 static int pid_sort(top_status_t *P, top_status_t *Q)
234 {
235 	/* Buggy wrt pids with high bit set */
236 	/* (linux pids are in [1..2^15-1]) */
237 	return (Q->pid - P->pid);
238 }
239 #endif
240 
mem_sort(top_status_t * P,top_status_t * Q)241 static int mem_sort(top_status_t *P, top_status_t *Q)
242 {
243 	/* We want to avoid unsigned->signed and truncation errors */
244 	if (Q->vsz < P->vsz) return -1;
245 	return Q->vsz != P->vsz; /* 0 if ==, 1 if > */
246 }
247 
248 
249 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
250 
pcpu_sort(top_status_t * P,top_status_t * Q)251 static int pcpu_sort(top_status_t *P, top_status_t *Q)
252 {
253 	/* Buggy wrt ticks with high bit set */
254 	/* Affects only processes for which ticks overflow */
255 	return (int)Q->pcpu - (int)P->pcpu;
256 }
257 
time_sort(top_status_t * P,top_status_t * Q)258 static int time_sort(top_status_t *P, top_status_t *Q)
259 {
260 	/* We want to avoid unsigned->signed and truncation errors */
261 	if (Q->ticks < P->ticks) return -1;
262 	return Q->ticks != P->ticks; /* 0 if ==, 1 if > */
263 }
264 
mult_lvl_cmp(void * a,void * b)265 static int mult_lvl_cmp(void* a, void* b)
266 {
267 	int i, cmp_val;
268 
269 	for (i = 0; i < SORT_DEPTH; i++) {
270 		cmp_val = (*sort_function[i])(a, b);
271 		if (cmp_val != 0)
272 			break;
273 	}
274 	return inverted ? -cmp_val : cmp_val;
275 }
276 
read_cpu_jiffy(FILE * fp,jiffy_counts_t * p_jif)277 static NOINLINE int read_cpu_jiffy(FILE *fp, jiffy_counts_t *p_jif)
278 {
279 #if !ENABLE_FEATURE_TOP_SMP_CPU
280 	static const char fmt[] ALIGN1 = "cpu %llu %llu %llu %llu %llu %llu %llu %llu";
281 #else
282 	static const char fmt[] ALIGN1 = "cp%*s %llu %llu %llu %llu %llu %llu %llu %llu";
283 #endif
284 	int ret;
285 
286 	if (!fgets(line_buf, LINE_BUF_SIZE, fp) || line_buf[0] != 'c' /* not "cpu" */)
287 		return 0;
288 	ret = sscanf(line_buf, fmt,
289 			&p_jif->usr, &p_jif->nic, &p_jif->sys, &p_jif->idle,
290 			&p_jif->iowait, &p_jif->irq, &p_jif->softirq,
291 			&p_jif->steal);
292 	if (ret >= 4) {
293 		p_jif->total = p_jif->usr + p_jif->nic + p_jif->sys + p_jif->idle
294 			+ p_jif->iowait + p_jif->irq + p_jif->softirq + p_jif->steal;
295 		/* procps 2.x does not count iowait as busy time */
296 		p_jif->busy = p_jif->total - p_jif->idle - p_jif->iowait;
297 	}
298 
299 	return ret;
300 }
301 
get_jiffy_counts(void)302 static void get_jiffy_counts(void)
303 {
304 	FILE* fp = xfopen_for_read("stat");
305 
306 	/* We need to parse cumulative counts even if SMP CPU display is on,
307 	 * they are used to calculate per process CPU% */
308 	prev_jif = cur_jif;
309 	if (read_cpu_jiffy(fp, &cur_jif) < 4)
310 		bb_error_msg_and_die("can't read '%s'", "/proc/stat");
311 
312 #if !ENABLE_FEATURE_TOP_SMP_CPU
313 	fclose(fp);
314 	return;
315 #else
316 	if (!smp_cpu_info) {
317 		fclose(fp);
318 		return;
319 	}
320 
321 	if (!num_cpus) {
322 		/* First time here. How many CPUs?
323 		 * There will be at least 1 /proc/stat line with cpu%d
324 		 */
325 		while (1) {
326 			cpu_jif = xrealloc_vector(cpu_jif, 1, num_cpus);
327 			if (read_cpu_jiffy(fp, &cpu_jif[num_cpus]) <= 4)
328 				break;
329 			num_cpus++;
330 		}
331 		if (num_cpus == 0) /* /proc/stat with only "cpu ..." line?! */
332 			smp_cpu_info = 0;
333 
334 		cpu_prev_jif = xzalloc(sizeof(cpu_prev_jif[0]) * num_cpus);
335 
336 		/* Otherwise the first per cpu display shows all 100% idles */
337 		usleep(50000);
338 	} else { /* Non first time invocation */
339 		jiffy_counts_t *tmp;
340 		int i;
341 
342 		/* First switch the sample pointers: no need to copy */
343 		tmp = cpu_prev_jif;
344 		cpu_prev_jif = cpu_jif;
345 		cpu_jif = tmp;
346 
347 		/* Get the new samples */
348 		for (i = 0; i < num_cpus; i++)
349 			read_cpu_jiffy(fp, &cpu_jif[i]);
350 	}
351 #endif
352 	fclose(fp);
353 }
354 
do_stats(void)355 static void do_stats(void)
356 {
357 	top_status_t *cur;
358 	pid_t pid;
359 	int n;
360 	unsigned i, last_i;
361 	struct save_hist *new_hist;
362 
363 	get_jiffy_counts();
364 	total_pcpu = 0;
365 	/* total_vsz = 0; */
366 	new_hist = xmalloc(sizeof(new_hist[0]) * ntop);
367 	/*
368 	 * Make a pass through the data to get stats.
369 	 */
370 	/* hist_iterations = 0; */
371 	i = 0;
372 	for (n = 0; n < ntop; n++) {
373 		cur = top + n;
374 
375 		/*
376 		 * Calculate time in cur process.  Time is sum of user time
377 		 * and system time
378 		 */
379 		pid = cur->pid;
380 		new_hist[n].ticks = cur->ticks;
381 		new_hist[n].pid = pid;
382 
383 		/* find matching entry from previous pass */
384 		cur->pcpu = 0;
385 		/* do not start at index 0, continue at last used one
386 		 * (brought hist_iterations from ~14000 down to 172) */
387 		last_i = i;
388 		if (prev_hist_count) do {
389 			if (prev_hist[i].pid == pid) {
390 				cur->pcpu = cur->ticks - prev_hist[i].ticks;
391 				total_pcpu += cur->pcpu;
392 				break;
393 			}
394 			i = (i+1) % prev_hist_count;
395 			/* hist_iterations++; */
396 		} while (i != last_i);
397 		/* total_vsz += cur->vsz; */
398 	}
399 
400 	/*
401 	 * Save cur frame's information.
402 	 */
403 	free(prev_hist);
404 	prev_hist = new_hist;
405 	prev_hist_count = ntop;
406 }
407 
408 #endif /* FEATURE_TOP_CPU_USAGE_PERCENTAGE */
409 
410 #if ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS && ENABLE_FEATURE_TOP_DECIMALS
411 /* formats 7 char string (8 with terminating NUL) */
fmt_100percent_8(char pbuf[8],unsigned value,unsigned total)412 static char *fmt_100percent_8(char pbuf[8], unsigned value, unsigned total)
413 {
414 	unsigned t;
415 	if (value >= total) { /* 100% ? */
416 		strcpy(pbuf, "  100% ");
417 		return pbuf;
418 	}
419 	/* else generate " [N/space]N.N% " string */
420 	value = 1000 * value / total;
421 	t = value / 100;
422 	value = value % 100;
423 	pbuf[0] = ' ';
424 	pbuf[1] = t ? t + '0' : ' ';
425 	pbuf[2] = '0' + (value / 10);
426 	pbuf[3] = '.';
427 	pbuf[4] = '0' + (value % 10);
428 	pbuf[5] = '%';
429 	pbuf[6] = ' ';
430 	pbuf[7] = '\0';
431 	return pbuf;
432 }
433 #endif
434 
435 #if ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS
display_cpus(int scr_width,char * scrbuf,int * lines_rem_p)436 static void display_cpus(int scr_width, char *scrbuf, int *lines_rem_p)
437 {
438 	/*
439 	 * xxx% = (cur_jif.xxx - prev_jif.xxx) / (cur_jif.total - prev_jif.total) * 100%
440 	 */
441 	unsigned total_diff;
442 	jiffy_counts_t *p_jif, *p_prev_jif;
443 	int i;
444 # if ENABLE_FEATURE_TOP_SMP_CPU
445 	int n_cpu_lines;
446 # endif
447 
448 	/* using (unsigned) casts to make operations cheaper */
449 # define  CALC_TOTAL_DIFF do { \
450 	total_diff = (unsigned)(p_jif->total - p_prev_jif->total); \
451 	if (total_diff == 0) total_diff = 1; \
452 } while (0)
453 
454 # if ENABLE_FEATURE_TOP_DECIMALS
455 #  define CALC_STAT(xxx) char xxx[8]
456 #  define SHOW_STAT(xxx) fmt_100percent_8(xxx, (unsigned)(p_jif->xxx - p_prev_jif->xxx), total_diff)
457 #  define FMT "%s"
458 # else
459 #  define CALC_STAT(xxx) unsigned xxx = 100 * (unsigned)(p_jif->xxx - p_prev_jif->xxx) / total_diff
460 #  define SHOW_STAT(xxx) xxx
461 #  define FMT "%4u%% "
462 # endif
463 
464 # if !ENABLE_FEATURE_TOP_SMP_CPU
465 	{
466 		i = 1;
467 		p_jif = &cur_jif;
468 		p_prev_jif = &prev_jif;
469 # else
470 	/* Loop thru CPU(s) */
471 	n_cpu_lines = smp_cpu_info ? num_cpus : 1;
472 	if (n_cpu_lines > *lines_rem_p)
473 		n_cpu_lines = *lines_rem_p;
474 
475 	for (i = 0; i < n_cpu_lines; i++) {
476 		p_jif = &cpu_jif[i];
477 		p_prev_jif = &cpu_prev_jif[i];
478 # endif
479 		CALC_TOTAL_DIFF;
480 
481 		{ /* Need a block: CALC_STAT are declarations */
482 			CALC_STAT(usr);
483 			CALC_STAT(sys);
484 			CALC_STAT(nic);
485 			CALC_STAT(idle);
486 			CALC_STAT(iowait);
487 			CALC_STAT(irq);
488 			CALC_STAT(softirq);
489 			/*CALC_STAT(steal);*/
490 
491 			snprintf(scrbuf, scr_width,
492 				/* Barely fits in 79 chars when in "decimals" mode. */
493 # if ENABLE_FEATURE_TOP_SMP_CPU
494 				"CPU%s:"FMT"usr"FMT"sys"FMT"nic"FMT"idle"FMT"io"FMT"irq"FMT"sirq",
495 				(smp_cpu_info ? utoa(i) : ""),
496 # else
497 				"CPU:"FMT"usr"FMT"sys"FMT"nic"FMT"idle"FMT"io"FMT"irq"FMT"sirq",
498 # endif
499 				SHOW_STAT(usr), SHOW_STAT(sys), SHOW_STAT(nic), SHOW_STAT(idle),
500 				SHOW_STAT(iowait), SHOW_STAT(irq), SHOW_STAT(softirq)
501 				/*, SHOW_STAT(steal) - what is this 'steal' thing? */
502 				/* I doubt anyone wants to know it */
503 			);
504 			puts(scrbuf);
505 		}
506 	}
507 # undef SHOW_STAT
508 # undef CALC_STAT
509 # undef FMT
510 	*lines_rem_p -= i;
511 }
512 #else  /* !ENABLE_FEATURE_TOP_CPU_GLOBAL_PERCENTS */
513 # define display_cpus(scr_width, scrbuf, lines_rem) ((void)0)
514 #endif
515 
516 enum {
517 	MI_MEMTOTAL,
518 	MI_MEMFREE,
519 	MI_MEMSHARED,
520 	MI_SHMEM,
521 	MI_BUFFERS,
522 	MI_CACHED,
523 	MI_SWAPTOTAL,
524 	MI_SWAPFREE,
525 	MI_DIRTY,
526 	MI_WRITEBACK,
527 	MI_ANONPAGES,
528 	MI_MAPPED,
529 	MI_SLAB,
530 	MI_MAX
531 };
532 
533 static void parse_meminfo(unsigned long meminfo[MI_MAX])
534 {
535 	static const char fields[] ALIGN1 =
536 		"MemTotal\0"
537 		"MemFree\0"
538 		"MemShared\0"
539 		"Shmem\0"
540 		"Buffers\0"
541 		"Cached\0"
542 		"SwapTotal\0"
543 		"SwapFree\0"
544 		"Dirty\0"
545 		"Writeback\0"
546 		"AnonPages\0"
547 		"Mapped\0"
548 		"Slab\0";
549 	char buf[60]; /* actual lines we expect are ~30 chars or less */
550 	FILE *f;
551 	int i;
552 
553 	memset(meminfo, 0, sizeof(meminfo[0]) * MI_MAX);
554 	f = xfopen_for_read("meminfo");
555 	while (fgets(buf, sizeof(buf), f) != NULL) {
556 		char *c = strchr(buf, ':');
557 		if (!c)
558 			continue;
559 		*c = '\0';
560 		i = index_in_strings(fields, buf);
561 		if (i >= 0)
562 			meminfo[i] = strtoul(c+1, NULL, 10);
563 	}
564 	fclose(f);
565 }
566 
567 static unsigned long display_header(int scr_width, int *lines_rem_p)
568 {
569 	char scrbuf[100]; /* [80] was a bit too low on 8Gb ram box */
570 	char *buf;
571 	unsigned long meminfo[MI_MAX];
572 
573 	parse_meminfo(meminfo);
574 
575 	/* Output memory info */
576 	if (scr_width > (int)sizeof(scrbuf))
577 		scr_width = sizeof(scrbuf);
578 	snprintf(scrbuf, scr_width,
579 		"Mem: %luK used, %luK free, %luK shrd, %luK buff, %luK cached",
580 		meminfo[MI_MEMTOTAL] - meminfo[MI_MEMFREE],
581 		meminfo[MI_MEMFREE],
582 		meminfo[MI_MEMSHARED] + meminfo[MI_SHMEM],
583 		meminfo[MI_BUFFERS],
584 		meminfo[MI_CACHED]);
585 	/* Go to top & clear to the end of screen */
586 	printf(OPT_BATCH_MODE ? "%s\n" : ESC"[H" ESC"[J" "%s\n", scrbuf);
587 	(*lines_rem_p)--;
588 
589 	/* Display CPU time split as percentage of total time.
590 	 * This displays either a cumulative line or one line per CPU.
591 	 */
592 	display_cpus(scr_width, scrbuf, lines_rem_p);
593 
594 	/* Read load average as a string */
595 	buf = stpcpy(scrbuf, "Load average: ");
596 	open_read_close("loadavg", buf, sizeof(scrbuf) - sizeof("Load average: "));
597 	scrbuf[scr_width - 1] = '\0';
598 	strchrnul(buf, '\n')[0] = '\0';
599 	puts(scrbuf);
600 	(*lines_rem_p)--;
601 
602 	return meminfo[MI_MEMTOTAL];
603 }
604 
605 static NOINLINE void display_process_list(int lines_rem, int scr_width)
606 {
607 	enum {
608 		BITS_PER_INT = sizeof(int) * 8
609 	};
610 
611 	top_status_t *s;
612 	unsigned long total_memory = display_header(scr_width, &lines_rem); /* or use total_vsz? */
613 	/* xxx_shift and xxx_scale variables allow us to replace
614 	 * expensive divides with multiply and shift */
615 	unsigned pmem_shift, pmem_scale, pmem_half;
616 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
617 	unsigned tmp_unsigned;
618 	unsigned pcpu_shift, pcpu_scale, pcpu_half;
619 	unsigned busy_jifs;
620 #endif
621 
622 	/* what info of the processes is shown */
623 	printf(OPT_BATCH_MODE ? "%.*s" : ESC"[7m" "%.*s" ESC"[m", scr_width,
624 		"  PID  PPID USER     STAT   VSZ %VSZ"
625 		IF_FEATURE_TOP_SMP_PROCESS(" CPU")
626 		IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE(" %CPU")
627 		" COMMAND");
628 	lines_rem--;
629 
630 #if ENABLE_FEATURE_TOP_DECIMALS
631 # define UPSCALE 1000
632 # define CALC_STAT(name, val) div_t name = div((val), 10)
633 # define SHOW_STAT(name) name.quot, '0'+name.rem
634 # define FMT "%3u.%c"
635 #else
636 # define UPSCALE 100
637 # define CALC_STAT(name, val) unsigned name = (val)
638 # define SHOW_STAT(name) name
639 # define FMT "%4u%%"
640 #endif
641 	/*
642 	 * %VSZ = s->vsz/MemTotal
643 	 */
644 	pmem_shift = BITS_PER_INT-11;
645 	pmem_scale = UPSCALE*(1U<<(BITS_PER_INT-11)) / total_memory;
646 	/* s->vsz is in kb. we want (s->vsz * pmem_scale) to never overflow */
647 	while (pmem_scale >= 512) {
648 		pmem_scale /= 4;
649 		pmem_shift -= 2;
650 	}
651 	pmem_half = (1U << pmem_shift) / (ENABLE_FEATURE_TOP_DECIMALS ? 20 : 2);
652 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
653 	busy_jifs = cur_jif.busy - prev_jif.busy;
654 	/* This happens if there were lots of short-lived processes
655 	 * between two top updates (e.g. compilation) */
656 	if (total_pcpu < busy_jifs) total_pcpu = busy_jifs;
657 
658 	/*
659 	 * CPU% = s->pcpu/sum(s->pcpu) * busy_cpu_ticks/total_cpu_ticks
660 	 * (pcpu is delta of sys+user time between samples)
661 	 */
662 	/* (cur_jif.xxx - prev_jif.xxx) and s->pcpu are
663 	 * in 0..~64000 range (HZ*update_interval).
664 	 * we assume that unsigned is at least 32-bit.
665 	 */
666 	pcpu_shift = 6;
667 	pcpu_scale = UPSCALE*64 * (uint16_t)busy_jifs;
668 	if (pcpu_scale == 0)
669 		pcpu_scale = 1;
670 	while (pcpu_scale < (1U << (BITS_PER_INT-2))) {
671 		pcpu_scale *= 4;
672 		pcpu_shift += 2;
673 	}
674 	tmp_unsigned = (uint16_t)(cur_jif.total - prev_jif.total) * total_pcpu;
675 	if (tmp_unsigned != 0)
676 		pcpu_scale /= tmp_unsigned;
677 	/* we want (s->pcpu * pcpu_scale) to never overflow */
678 	while (pcpu_scale >= 1024) {
679 		pcpu_scale /= 4;
680 		pcpu_shift -= 2;
681 	}
682 	pcpu_half = (1U << pcpu_shift) / (ENABLE_FEATURE_TOP_DECIMALS ? 20 : 2);
683 	/* printf(" pmem_scale=%u pcpu_scale=%u ", pmem_scale, pcpu_scale); */
684 #endif
685 
686 	/* Ok, all preliminary data is ready, go through the list */
687 	scr_width += 2; /* account for leading '\n' and trailing NUL */
688 	if (lines_rem > ntop - G_scroll_ofs)
689 		lines_rem = ntop - G_scroll_ofs;
690 	s = top + G_scroll_ofs;
691 	while (--lines_rem >= 0) {
692 		char vsz_str_buf[8];
693 		unsigned col;
694 
695 		CALC_STAT(pmem, (s->vsz*pmem_scale + pmem_half) >> pmem_shift);
696 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
697 		CALC_STAT(pcpu, (s->pcpu*pcpu_scale + pcpu_half) >> pcpu_shift);
698 #endif
699 
700 		smart_ulltoa5(s->vsz, vsz_str_buf, " mgtpezy");
701 		/* PID PPID USER STAT VSZ %VSZ [%CPU] COMMAND */
702 		col = snprintf(line_buf, scr_width,
703 				"\n" "%5u%6u %-8.8s %s  %.5s" FMT
704 				IF_FEATURE_TOP_SMP_PROCESS(" %3d")
705 				IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE(FMT)
706 				" ",
707 				s->pid, s->ppid, get_cached_username(s->uid),
708 				s->state, vsz_str_buf,
709 				SHOW_STAT(pmem)
710 				IF_FEATURE_TOP_SMP_PROCESS(, s->last_seen_on_cpu)
711 				IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE(, SHOW_STAT(pcpu))
712 		);
713 		if ((int)(scr_width - col) > 1)
714 			read_cmdline(line_buf + col, scr_width - col, s->pid, s->comm);
715 		fputs_stdout(line_buf);
716 		/* printf(" %d/%d %lld/%lld", s->pcpu, total_pcpu,
717 			cur_jif.busy - prev_jif.busy, cur_jif.total - prev_jif.total); */
718 		s++;
719 	}
720 	/* printf(" %d", hist_iterations); */
721 	bb_putchar(OPT_BATCH_MODE ? '\n' : '\r');
722 	fflush_all();
723 }
724 #undef UPSCALE
725 #undef SHOW_STAT
726 #undef CALC_STAT
727 #undef FMT
728 
729 static void clearmems(void)
730 {
731 	clear_username_cache();
732 	free(top);
733 	top = NULL;
734 }
735 
736 #if ENABLE_FEATURE_TOP_INTERACTIVE
737 static void reset_term(void)
738 {
739 	if (!OPT_BATCH_MODE)
740 		tcsetattr_stdin_TCSANOW(&initial_settings);
741 }
742 
743 static void sig_catcher(int sig)
744 {
745 	reset_term();
746 	kill_myself_with_sig(sig);
747 }
748 #endif /* FEATURE_TOP_INTERACTIVE */
749 
750 /*
751  * TOPMEM support
752  */
753 
754 typedef unsigned long mem_t;
755 
756 typedef struct topmem_status_t {
757 	unsigned pid;
758 	char comm[COMM_LEN];
759 	/* vsz doesn't count /dev/xxx mappings except /dev/zero */
760 	mem_t vsz     ;
761 	mem_t vszrw   ;
762 	mem_t rss     ;
763 	mem_t rss_sh  ;
764 	mem_t dirty   ;
765 	mem_t dirty_sh;
766 	mem_t stack   ;
767 } topmem_status_t;
768 
769 enum { NUM_SORT_FIELD = 7 };
770 
771 #define topmem ((topmem_status_t*)top)
772 
773 #if ENABLE_FEATURE_TOPMEM
774 
775 static int topmem_sort(char *a, char *b)
776 {
777 	int n;
778 	mem_t l, r;
779 
780 	n = offsetof(topmem_status_t, vsz) + (sort_field * sizeof(mem_t));
781 	l = *(mem_t*)(a + n);
782 	r = *(mem_t*)(b + n);
783 	if (l == r) {
784 		l = ((topmem_status_t*)a)->dirty;
785 		r = ((topmem_status_t*)b)->dirty;
786 	}
787 	/* We want to avoid unsigned->signed and truncation errors */
788 	/* l>r: -1, l=r: 0, l<r: 1 */
789 	n = (l > r) ? -1 : (l != r);
790 	return inverted ? -n : n;
791 }
792 
793 /* display header info (meminfo / loadavg) */
794 static void display_topmem_header(int scr_width, int *lines_rem_p)
795 {
796 	unsigned long meminfo[MI_MAX];
797 
798 	parse_meminfo(meminfo);
799 
800 	snprintf(line_buf, LINE_BUF_SIZE,
801 		"Mem total:%lu anon:%lu map:%lu free:%lu",
802 		meminfo[MI_MEMTOTAL],
803 		meminfo[MI_ANONPAGES],
804 		meminfo[MI_MAPPED],
805 		meminfo[MI_MEMFREE]);
806 	printf(OPT_BATCH_MODE ? "%.*s\n" : ESC"[H" ESC"[J" "%.*s\n", scr_width, line_buf);
807 
808 	snprintf(line_buf, LINE_BUF_SIZE,
809 		" slab:%lu buf:%lu cache:%lu dirty:%lu write:%lu",
810 		meminfo[MI_SLAB],
811 		meminfo[MI_BUFFERS],
812 		meminfo[MI_CACHED],
813 		meminfo[MI_DIRTY],
814 		meminfo[MI_WRITEBACK]);
815 	printf("%.*s\n", scr_width, line_buf);
816 
817 	snprintf(line_buf, LINE_BUF_SIZE,
818 		"Swap total:%lu free:%lu", // TODO: % used?
819 		meminfo[MI_SWAPTOTAL],
820 		meminfo[MI_SWAPFREE]);
821 	printf("%.*s\n", scr_width, line_buf);
822 
823 	(*lines_rem_p) -= 3;
824 }
825 
826 static void ulltoa6_and_space(unsigned long long ul, char buf[6])
827 {
828 	/* see http://en.wikipedia.org/wiki/Tera */
829 	smart_ulltoa5(ul, buf, " mgtpezy")[0] = ' ';
830 }
831 
832 static NOINLINE void display_topmem_process_list(int lines_rem, int scr_width)
833 {
834 #define HDR_STR "  PID   VSZ VSZRW   RSS (SHR) DIRTY (SHR) STACK"
835 #define MIN_WIDTH sizeof(HDR_STR)
836 	const topmem_status_t *s = topmem + G_scroll_ofs;
837 	char *cp, ch;
838 
839 	display_topmem_header(scr_width, &lines_rem);
840 
841 	strcpy(line_buf, HDR_STR " COMMAND");
842 	/* Mark the ^FIELD^ we sort by */
843 	cp = &line_buf[5 + sort_field * 6];
844 	ch = "^_"[inverted];
845 	cp[6] = ch;
846 	do *cp++ = ch; while (*cp == ' ');
847 
848 	printf(OPT_BATCH_MODE ? "%.*s" : ESC"[7m" "%.*s" ESC"[m", scr_width, line_buf);
849 	lines_rem--;
850 
851 	if (lines_rem > ntop - G_scroll_ofs)
852 		lines_rem = ntop - G_scroll_ofs;
853 	while (--lines_rem >= 0) {
854 		/* PID VSZ VSZRW RSS (SHR) DIRTY (SHR) COMMAND */
855 		ulltoa6_and_space(s->pid     , &line_buf[0*6]);
856 		ulltoa6_and_space(s->vsz     , &line_buf[1*6]);
857 		ulltoa6_and_space(s->vszrw   , &line_buf[2*6]);
858 		ulltoa6_and_space(s->rss     , &line_buf[3*6]);
859 		ulltoa6_and_space(s->rss_sh  , &line_buf[4*6]);
860 		ulltoa6_and_space(s->dirty   , &line_buf[5*6]);
861 		ulltoa6_and_space(s->dirty_sh, &line_buf[6*6]);
862 		ulltoa6_and_space(s->stack   , &line_buf[7*6]);
863 		line_buf[8*6] = '\0';
864 		if (scr_width > (int)MIN_WIDTH) {
865 			read_cmdline(&line_buf[8*6], scr_width - MIN_WIDTH, s->pid, s->comm);
866 		}
867 		printf("\n""%.*s", scr_width, line_buf);
868 		s++;
869 	}
870 	bb_putchar(OPT_BATCH_MODE ? '\n' : '\r');
871 	fflush_all();
872 #undef HDR_STR
873 #undef MIN_WIDTH
874 }
875 
876 #else
877 void display_topmem_process_list(int lines_rem, int scr_width);
878 int topmem_sort(char *a, char *b);
879 #endif /* TOPMEM */
880 
881 /*
882  * end TOPMEM support
883  */
884 
885 enum {
886 	TOP_MASK = 0
887 		| PSSCAN_PID
888 		| PSSCAN_PPID
889 		| PSSCAN_VSZ
890 		| PSSCAN_STIME
891 		| PSSCAN_UTIME
892 		| PSSCAN_STATE
893 		| PSSCAN_COMM
894 		| PSSCAN_CPU
895 		| PSSCAN_UIDGID,
896 	TOPMEM_MASK = 0
897 		| PSSCAN_PID
898 		| PSSCAN_SMAPS
899 		| PSSCAN_COMM,
900 	EXIT_MASK = 0,
901 	NO_RESCAN_MASK = (unsigned)-1,
902 };
903 
904 #if ENABLE_FEATURE_TOP_INTERACTIVE
905 static unsigned handle_input(unsigned scan_mask, duration_t interval)
906 {
907 	if (option_mask32 & OPT_EOF) {
908 		/* EOF on stdin ("top </dev/null") */
909 		sleep_for_duration(interval);
910 		return scan_mask;
911 	}
912 
913 	while (1) {
914 		int32_t c;
915 
916 		c = read_key(STDIN_FILENO, G.kbd_input, interval * 1000);
917 		if (c == -1 && errno != EAGAIN) {
918 			/* error/EOF */
919 			option_mask32 |= OPT_EOF;
920 			break;
921 		}
922 		interval = 0;
923 
924 		if (c == initial_settings.c_cc[VINTR])
925 			return EXIT_MASK;
926 		if (c == initial_settings.c_cc[VEOF])
927 			return EXIT_MASK;
928 
929 		if (c == KEYCODE_UP) {
930 			G_scroll_ofs--;
931 			goto normalize_ofs;
932 		}
933 		if (c == KEYCODE_DOWN) {
934 			G_scroll_ofs++;
935 			goto normalize_ofs;
936 		}
937 		if (c == KEYCODE_HOME) {
938 			G_scroll_ofs = 0;
939 			goto normalize_ofs;
940 		}
941 		if (c == KEYCODE_END) {
942 			G_scroll_ofs = ntop - G.lines / 2;
943 			goto normalize_ofs;
944 		}
945 		if (c == KEYCODE_PAGEUP) {
946 			G_scroll_ofs -= G.lines / 2;
947 			goto normalize_ofs;
948 		}
949 		if (c == KEYCODE_PAGEDOWN) {
950 			G_scroll_ofs += G.lines / 2;
951  normalize_ofs:
952 			if (G_scroll_ofs >= ntop)
953 				G_scroll_ofs = ntop - 1;
954 			if (G_scroll_ofs < 0)
955 				G_scroll_ofs = 0;
956 			return NO_RESCAN_MASK;
957 		}
958 
959 		c |= 0x20; /* lowercase */
960 		if (c == 'q')
961 			return EXIT_MASK;
962 
963 		if (c == 'n') {
964 			IF_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
965 			sort_function[0] = pid_sort;
966 			continue;
967 		}
968 		if (c == 'm') {
969 			IF_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
970 			sort_function[0] = mem_sort;
971 # if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
972 			sort_function[1] = pcpu_sort;
973 			sort_function[2] = time_sort;
974 # endif
975 			continue;
976 		}
977 # if ENABLE_FEATURE_SHOW_THREADS
978 		if (c == 'h'
979 		IF_FEATURE_TOPMEM(&& scan_mask != TOPMEM_MASK)
980 		) {
981 			scan_mask ^= PSSCAN_TASKS;
982 #  if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
983 			free(prev_hist);
984 			prev_hist = NULL;
985 			prev_hist_count = 0;
986 #   endif
987 			continue;
988 		}
989 # endif
990 # if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
991 		if (c == 'p') {
992 			IF_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
993 			sort_function[0] = pcpu_sort;
994 			sort_function[1] = mem_sort;
995 			sort_function[2] = time_sort;
996 			continue;
997 		}
998 		if (c == 't') {
999 			IF_FEATURE_TOPMEM(scan_mask = TOP_MASK;)
1000 			sort_function[0] = time_sort;
1001 			sort_function[1] = mem_sort;
1002 			sort_function[2] = pcpu_sort;
1003 			continue;
1004 		}
1005 #  if ENABLE_FEATURE_TOPMEM
1006 		if (c == 's') {
1007 			scan_mask = TOPMEM_MASK;
1008 			sort_field = (sort_field + 1) % NUM_SORT_FIELD;
1009 			free(prev_hist);
1010 			prev_hist = NULL;
1011 			prev_hist_count = 0;
1012 			continue;
1013 		}
1014 #  endif
1015 		if (c == 'r') {
1016 			inverted ^= 1;
1017 			continue;
1018 		}
1019 #  if ENABLE_FEATURE_TOP_SMP_CPU
1020 		/* procps-2.0.18 uses 'C', 3.2.7 uses '1' */
1021 		if (c == 'c' || c == '1') {
1022 			/* User wants to toggle per cpu <> aggregate */
1023 			if (smp_cpu_info) {
1024 				free(cpu_prev_jif);
1025 				free(cpu_jif);
1026 				cpu_jif = &cur_jif;
1027 				cpu_prev_jif = &prev_jif;
1028 			} else {
1029 				/* Prepare for xrealloc() */
1030 				cpu_jif = cpu_prev_jif = NULL;
1031 			}
1032 			num_cpus = 0;
1033 			smp_cpu_info = !smp_cpu_info;
1034 			get_jiffy_counts();
1035 			continue;
1036 		}
1037 #  endif
1038 # endif
1039 		break; /* unknown key -> force refresh */
1040 	}
1041 
1042 	return scan_mask;
1043 }
1044 #endif
1045 
1046 //usage:#if ENABLE_FEATURE_SHOW_THREADS || ENABLE_FEATURE_TOP_SMP_CPU
1047 //usage:# define IF_SHOW_THREADS_OR_TOP_SMP(...) __VA_ARGS__
1048 //usage:#else
1049 //usage:# define IF_SHOW_THREADS_OR_TOP_SMP(...)
1050 //usage:#endif
1051 //usage:#define top_trivial_usage
1052 //usage:       "[-b"IF_FEATURE_TOPMEM("m")IF_FEATURE_SHOW_THREADS("H")"]"
1053 //usage:       " [-n COUNT] [-d SECONDS]"
1054 //usage:#define top_full_usage "\n\n"
1055 //usage:       "Show a view of process activity in real time."
1056 //usage:   "\n""Read the status of all processes from /proc each SECONDS"
1057 //usage:   "\n""and show a screenful of them."
1058 //usage:   "\n"
1059 //usage:	IF_FEATURE_TOP_INTERACTIVE(
1060 //usage:       "Keys:"
1061 //usage:   "\n""	N/M"
1062 //usage:                IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE("/P")
1063 //usage:                IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE("/T")
1064 //usage:           ": " IF_FEATURE_TOPMEM("show CPU usage, ") "sort by pid/mem"
1065 //usage:                IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE("/cpu")
1066 //usage:                IF_FEATURE_TOP_CPU_USAGE_PERCENTAGE("/time")
1067 //usage:	IF_FEATURE_TOPMEM(
1068 //usage:   "\n""	S: show memory"
1069 //usage:	)
1070 //usage:   "\n""	R: reverse sort"
1071 //usage:	IF_SHOW_THREADS_OR_TOP_SMP(
1072 //usage:   "\n""	"
1073 //usage:                IF_FEATURE_SHOW_THREADS("H: toggle threads")
1074 //usage:                IF_FEATURE_SHOW_THREADS(IF_FEATURE_TOP_SMP_CPU(", "))
1075 //usage:                IF_FEATURE_TOP_SMP_CPU("1: toggle SMP")
1076 //usage:	)
1077 //usage:   "\n""	Q,^C: exit"
1078 //usage:   "\n""Options:"
1079 //usage:	)
1080 //usage:   "\n""	-b	Batch mode"
1081 //usage:   "\n""	-n N	Exit after N iterations"
1082 //usage:   "\n""	-d SEC	Delay between updates"
1083 //usage:	IF_FEATURE_TOPMEM(
1084 //usage:   "\n""	-m	Same as 's' key"
1085 //usage:	)
1086 //usage:	IF_FEATURE_SHOW_THREADS(
1087 //usage:   "\n""	-H	Show threads"
1088 //usage:	)
1089 
1090 /* Interactive testing:
1091  * echo sss | ./busybox top
1092  * - shows memory screen
1093  * echo sss | ./busybox top -bn1 >mem
1094  * - saves memory screen - the *whole* list, not first NROWS processes!
1095  * echo .m.s.s.s.s.s.s.q | ./busybox top -b >z
1096  * - saves several different screens, and exits
1097  *
1098  * TODO: -i STRING param as a better alternative?
1099  */
1100 
1101 int top_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
1102 int top_main(int argc UNUSED_PARAM, char **argv)
1103 {
1104 	duration_t interval;
1105 	int iterations;
1106 	unsigned col;
1107 	char *str_interval, *str_iterations;
1108 	unsigned scan_mask = TOP_MASK;
1109 
1110 	INIT_G();
1111 
1112 	interval = 5; /* default update interval is 5 seconds */
1113 	iterations = 0; /* infinite */
1114 #if ENABLE_FEATURE_TOP_SMP_CPU
1115 	/*num_cpus = 0;*/
1116 	/*smp_cpu_info = 0;*/  /* to start with show aggregate */
1117 	cpu_jif = &cur_jif;
1118 	cpu_prev_jif = &prev_jif;
1119 #endif
1120 
1121 	/* all args are options; -n NUM */
1122 	make_all_argv_opts(argv); /* options can be specified w/o dash */
1123 	col = getopt32(argv, "d:n:bHm", &str_interval, &str_iterations);
1124 	/* NB: -m and -H are accepted even if not configured */
1125 #if ENABLE_FEATURE_TOPMEM
1126 	if (col & OPT_m) /* -m (busybox specific) */
1127 		scan_mask = TOPMEM_MASK;
1128 #endif
1129 	if (col & OPT_d) {
1130 		/* work around for "-d 1" -> "-d -1" done by make_all_argv_opts() */
1131 		if (str_interval[0] == '-')
1132 			str_interval++;
1133 		interval = parse_duration_str(str_interval);
1134 		/* Need to limit it to not overflow poll timeout */
1135 		if (interval > INT_MAX / 1000)
1136 			interval = INT_MAX / 1000;
1137 	}
1138 	if (col & OPT_n) {
1139 		if (str_iterations[0] == '-')
1140 			str_iterations++;
1141 		iterations = xatou(str_iterations);
1142 	}
1143 #if ENABLE_FEATURE_SHOW_THREADS
1144 	if (col & OPT_H) {
1145 		scan_mask |= PSSCAN_TASKS;
1146 	}
1147 #endif
1148 
1149 	/* change to /proc */
1150 	xchdir("/proc");
1151 
1152 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
1153 	sort_function[0] = pcpu_sort;
1154 	sort_function[1] = mem_sort;
1155 	sort_function[2] = time_sort;
1156 #else
1157 	sort_function[0] = mem_sort;
1158 #endif
1159 
1160 	if (OPT_BATCH_MODE) {
1161 		option_mask32 |= OPT_EOF;
1162 	}
1163 #if ENABLE_FEATURE_TOP_INTERACTIVE
1164 	else {
1165 		/* Turn on unbuffered input; turn off echoing, ^C ^Z etc */
1166 		set_termios_to_raw(STDIN_FILENO, &initial_settings, TERMIOS_CLEAR_ISIG);
1167 		die_func = reset_term;
1168 	}
1169 
1170 	bb_signals(BB_FATAL_SIGS, sig_catcher);
1171 
1172 	/* Eat initial input, if any */
1173 	scan_mask = handle_input(scan_mask, 0);
1174 #endif
1175 
1176 	while (scan_mask != EXIT_MASK) {
1177 		IF_FEATURE_TOP_INTERACTIVE(unsigned new_mask;)
1178 		procps_status_t *p = NULL;
1179 
1180 		if (OPT_BATCH_MODE) {
1181 			G.lines = INT_MAX;
1182 			col = LINE_BUF_SIZE - 2; /* +2 bytes for '\n', NUL */
1183 		} else {
1184 			G.lines = 24; /* default */
1185 			col = 79;
1186 			/* We output to stdout, we need size of stdout (not stdin)! */
1187 			get_terminal_width_height(STDOUT_FILENO, &col, &G.lines);
1188 			if (G.lines < 5 || col < 10) {
1189 				sleep_for_duration(interval);
1190 				continue;
1191 			}
1192 			if (col > LINE_BUF_SIZE - 2)
1193 				col = LINE_BUF_SIZE - 2;
1194 		}
1195 
1196 		/* read process IDs & status for all the processes */
1197 		ntop = 0;
1198 		while ((p = procps_scan(p, scan_mask)) != NULL) {
1199 			int n;
1200 
1201 			IF_FEATURE_TOPMEM(if (scan_mask != TOPMEM_MASK)) {
1202 				n = ntop;
1203 				top = xrealloc_vector(top, 6, ntop++);
1204 				top[n].pid = p->pid;
1205 				top[n].ppid = p->ppid;
1206 				top[n].vsz = p->vsz;
1207 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
1208 				top[n].ticks = p->stime + p->utime;
1209 #endif
1210 				top[n].uid = p->uid;
1211 				strcpy(top[n].state, p->state);
1212 				strcpy(top[n].comm, p->comm);
1213 #if ENABLE_FEATURE_TOP_SMP_PROCESS
1214 				top[n].last_seen_on_cpu = p->last_seen_on_cpu;
1215 #endif
1216 			}
1217 #if ENABLE_FEATURE_TOPMEM
1218 			else { /* TOPMEM */
1219 				if (!(p->smaps.mapped_ro | p->smaps.mapped_rw))
1220 					continue; /* kernel threads are ignored */
1221 				n = ntop;
1222 				/* No bug here - top and topmem are the same */
1223 				top = xrealloc_vector(topmem, 6, ntop++);
1224 				strcpy(topmem[n].comm, p->comm);
1225 				topmem[n].pid      = p->pid;
1226 				topmem[n].vsz      = p->smaps.mapped_rw + p->smaps.mapped_ro;
1227 				topmem[n].vszrw    = p->smaps.mapped_rw;
1228 				topmem[n].rss_sh   = p->smaps.shared_clean + p->smaps.shared_dirty;
1229 				topmem[n].rss      = p->smaps.private_clean + p->smaps.private_dirty + topmem[n].rss_sh;
1230 				topmem[n].dirty    = p->smaps.private_dirty + p->smaps.shared_dirty;
1231 				topmem[n].dirty_sh = p->smaps.shared_dirty;
1232 				topmem[n].stack    = p->smaps.stack;
1233 			}
1234 #endif
1235 		} /* end of "while we read /proc" */
1236 		if (ntop == 0) {
1237 			bb_simple_error_msg("no process info in /proc");
1238 			break;
1239 		}
1240 
1241 		IF_FEATURE_TOPMEM(if (scan_mask != TOPMEM_MASK)) {
1242 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
1243 			if (!prev_hist_count) {
1244 				do_stats();
1245 				usleep(100000);
1246 				clearmems();
1247 				continue;
1248 			}
1249 			do_stats();
1250 			/* TODO: we don't need to sort all 10000 processes, we need to find top 24! */
1251 			qsort(top, ntop, sizeof(top_status_t), (void*)mult_lvl_cmp);
1252 #else
1253 			qsort(top, ntop, sizeof(top_status_t), (void*)(sort_function[0]));
1254 #endif
1255 		}
1256 #if ENABLE_FEATURE_TOPMEM
1257 		else { /* TOPMEM */
1258 			qsort(topmem, ntop, sizeof(topmem_status_t), (void*)topmem_sort);
1259 		}
1260 #endif
1261  IF_FEATURE_TOP_INTERACTIVE(display:)
1262 		IF_FEATURE_TOPMEM(if (scan_mask != TOPMEM_MASK)) {
1263 			display_process_list(G.lines, col);
1264 		}
1265 #if ENABLE_FEATURE_TOPMEM
1266 		else { /* TOPMEM */
1267 			display_topmem_process_list(G.lines, col);
1268 		}
1269 #endif
1270 		if (iterations >= 0 && !--iterations)
1271 			break;
1272 #if !ENABLE_FEATURE_TOP_INTERACTIVE
1273 		clearmems();
1274 		sleep_for_duration(interval);
1275 #else
1276 		new_mask = handle_input(scan_mask, interval);
1277 		if (new_mask == NO_RESCAN_MASK)
1278 			goto display;
1279 		scan_mask = new_mask;
1280 		clearmems();
1281 #endif
1282 	} /* end of "while (not Q)" */
1283 
1284 	bb_putchar('\n');
1285 #if ENABLE_FEATURE_TOP_INTERACTIVE
1286 	reset_term();
1287 #endif
1288 	if (ENABLE_FEATURE_CLEAN_UP) {
1289 		clearmems();
1290 #if ENABLE_FEATURE_TOP_CPU_USAGE_PERCENTAGE
1291 		free(prev_hist);
1292 #endif
1293 	}
1294 	return EXIT_SUCCESS;
1295 }
1296