summaryrefslogtreecommitdiffhomepage
path: root/procps/ps.c
blob: afd9813131d5eb0b8a00535bf3febd9498ecbf41 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
/* vi: set sw=4 ts=4: */
/*
 * Mini ps implementation(s) for busybox
 *
 * Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
 * Fix for SELinux Support:(c)2007 Hiroshi Shinji <shiroshi@my.email.ne.jp>
 *                         (c)2007 Yuichi Nakamura <ynakam@hitachisoft.jp>
 *
 * Licensed under GPLv2, see file LICENSE in this source tree.
 */
//config:config PS
//config:	bool "ps (11 kb)"
//config:	default y
//config:	help
//config:	ps gives a snapshot of the current processes.
//config:
//config:config FEATURE_PS_WIDE
//config:	bool "Enable wide output (-w)"
//config:	default y
//config:	depends on PS && !DESKTOP
//config:	help
//config:	Support argument 'w' for wide output.
//config:	If given once, 132 chars are printed, and if given more
//config:	than once, the length is unlimited.
//config:
//config:config FEATURE_PS_LONG
//config:	bool "Enable long output (-l)"
//config:	default y
//config:	depends on PS && !DESKTOP
//config:	help
//config:	Support argument 'l' for long output.
//config:	Adds fields PPID, RSS, START, TIME & TTY
//config:
//config:config FEATURE_PS_TIME
//config:	bool "Enable -o time and -o etime specifiers"
//config:	default y
//config:	depends on PS && DESKTOP
//config:	select PLATFORM_LINUX
//config:
//config:config FEATURE_PS_ADDITIONAL_COLUMNS
//config:	bool "Enable -o rgroup, -o ruser, -o nice specifiers"
//config:	default y
//config:	depends on PS && DESKTOP
//config:
//config:config FEATURE_PS_UNUSUAL_SYSTEMS
//config:	bool "Support Linux prior to 2.4.0 and non-ELF systems"
//config:	default n
//config:	depends on FEATURE_PS_TIME
//config:	help
//config:	Include support for measuring HZ on old kernels and non-ELF systems
//config:	(if you are on Linux 2.4.0+ and use ELF, you don't need this)

//applet:IF_PS(APPLET(ps, BB_DIR_BIN, BB_SUID_DROP))
/* can't be NOEXEC: uses ELF aux vector. To have it, we must be a normal, execed process */

//kbuild:lib-$(CONFIG_PS) += ps.o

//usage:#if ENABLE_DESKTOP
//usage:
//usage:#define ps_trivial_usage
//usage:       "[-o COL1,COL2=HEADER]" IF_FEATURE_SHOW_THREADS(" [-T]")
//usage:#define ps_full_usage "\n\n"
//usage:       "Show list of processes\n"
//usage:     "\n	-o COL1,COL2=HEADER	Select columns for display"
//usage:	IF_FEATURE_SHOW_THREADS(
//usage:     "\n	-T			Show threads"
//usage:	)
//usage:
//usage:#else /* !ENABLE_DESKTOP */
//usage:
//usage:#if !ENABLE_SELINUX && !ENABLE_FEATURE_PS_WIDE
//usage:#define USAGE_PS "\nThis version of ps accepts no options"
//usage:#else
//usage:#define USAGE_PS ""
//usage:#endif
//usage:
//usage:#define ps_trivial_usage
//usage:       ""
//usage:#define ps_full_usage "\n\n"
//usage:       "Show list of processes\n"
//usage:	USAGE_PS
//usage:	IF_SELINUX(
//usage:     "\n	-Z	Show selinux context"
//usage:	)
//usage:	IF_FEATURE_PS_WIDE(
//usage:     "\n	w	Wide output"
//usage:	)
//usage:	IF_FEATURE_PS_LONG(
//usage:     "\n	l	Long output"
//usage:	)
//usage:	IF_FEATURE_SHOW_THREADS(
//usage:     "\n	T	Show threads"
//usage:	)
//usage:
//usage:#endif /* ENABLE_DESKTOP */
//usage:
//usage:#define ps_example_usage
//usage:       "$ ps\n"
//usage:       "  PID  Uid      Gid State Command\n"
//usage:       "    1 root     root     S init\n"
//usage:       "    2 root     root     S [kflushd]\n"
//usage:       "    3 root     root     S [kupdate]\n"
//usage:       "    4 root     root     S [kpiod]\n"
//usage:       "    5 root     root     S [kswapd]\n"
//usage:       "  742 andersen andersen S [bash]\n"
//usage:       "  743 andersen andersen S -bash\n"
//usage:       "  745 root     root     S [getty]\n"
//usage:       " 2990 andersen andersen R ps\n"

#include "libbb.h"
#include "common_bufsiz.h"
#ifdef __linux__
# include <sys/sysinfo.h>
#endif

/* Absolute maximum on output line length */
enum { MAX_WIDTH = 2*1024 };

#if ENABLE_FEATURE_PS_TIME || ENABLE_FEATURE_PS_LONG
static unsigned long get_uptime(void)
{
#ifdef __linux__
	struct sysinfo info;
	if (sysinfo(&info) < 0)
		return 0;
	return info.uptime;
#elif 1
	unsigned long uptime;
	char buf[sizeof(uptime)*3 + 2];
	/* /proc/uptime is "UPTIME_SEC.NN IDLE_SEC.NN\n"
	 * (where IDLE is cumulative over all CPUs)
	 */
	if (open_read_close("/proc/uptime", buf, sizeof(buf)) <= 0)
		bb_perror_msg_and_die("can't read '%s'", "/proc/uptime");
	buf[sizeof(buf)-1] = '\0';
	sscanf(buf, "%lu", &uptime);
	return uptime;
#else
	struct timespec ts;
	if (clock_gettime(CLOCK_MONOTONIC, &ts) < 0)
		return 0;
	return ts.tv_sec;
#endif
}
#endif

#if ENABLE_DESKTOP

#include <sys/times.h> /* for times() */
#ifndef AT_CLKTCK
# define AT_CLKTCK 17
#endif

/* TODO:
 * http://pubs.opengroup.org/onlinepubs/9699919799/utilities/ps.html
 * specifies (for XSI-conformant systems) following default columns
 * (l and f mark columns shown with -l and -f respectively):
 * F     l   Flags (octal and additive) associated with the process (??)
 * S     l   The state of the process
 * UID   f,l The user ID; the login name is printed with -f
 * PID       The process ID
 * PPID  f,l The parent process
 * C     f,l Processor utilization
 * PRI   l   The priority of the process; higher numbers mean lower priority
 * NI    l   Nice value
 * ADDR  l   The address of the process
 * SZ    l   The size in blocks of the core image of the process
 * WCHAN l   The event for which the process is waiting or sleeping
 * STIME f   Starting time of the process
 * TTY       The controlling terminal for the process
 * TIME      The cumulative execution time for the process
 * CMD       The command name; the full command line is shown with -f
 */
typedef struct {
	uint16_t width;
	char name6[6];
	const char *header;
	void (*f)(char *buf, int size, const procps_status_t *ps);
	int ps_flags;
} ps_out_t;

struct globals {
	ps_out_t* out;
	int out_cnt;
	int print_header;
	int need_flags;
	char *buffer;
	unsigned terminal_width;
#if ENABLE_FEATURE_PS_TIME
	unsigned kernel_HZ;
	unsigned long seconds_since_boot;
#endif
} FIX_ALIASING;
#define G (*(struct globals*)bb_common_bufsiz1)
#define out                (G.out               )
#define out_cnt            (G.out_cnt           )
#define print_header       (G.print_header      )
#define need_flags         (G.need_flags        )
#define buffer             (G.buffer            )
#define terminal_width     (G.terminal_width    )
#define kernel_HZ          (G.kernel_HZ         )
#define INIT_G() do { setup_common_bufsiz(); } while (0)

#if ENABLE_FEATURE_PS_TIME
/* for ELF executables, notes are pushed before environment and args */
/* try "LD_SHOW_AUXV=1 /bin/true" */
static uintptr_t find_elf_note(uintptr_t findme)
{
	uintptr_t *ep = (uintptr_t *) environ;

	while (*ep++)
		continue;
	while (*ep) {
		if (ep[0] == findme) {
			return ep[1];
		}
		ep += 2;
	}
	return -1;
}

# if ENABLE_FEATURE_PS_UNUSUAL_SYSTEMS
static unsigned get_HZ_by_waiting(void)
{
	struct timeval tv1, tv2;
	unsigned t1, t2, r, hz;
	unsigned cnt = cnt; /* for compiler */
	int diff;

	r = 0;

	/* Wait for times() to reach new tick */
	t1 = times(NULL);
	do {
		t2 = times(NULL);
	} while (t2 == t1);
	gettimeofday(&tv2, NULL);

	do {
		t1 = t2;
		tv1.tv_usec = tv2.tv_usec;

		/* Wait exactly one times() tick */
		do {
			t2 = times(NULL);
		} while (t2 == t1);
		gettimeofday(&tv2, NULL);

		/* Calculate ticks per sec, rounding up to even */
		diff = tv2.tv_usec - tv1.tv_usec;
		if (diff <= 0) diff += 1000000;
		hz = 1000000u / (unsigned)diff;
		hz = (hz+1) & ~1;

		/* Count how many same hz values we saw */
		if (r != hz) {
			r = hz;
			cnt = 0;
		}
		cnt++;
	} while (cnt < 3); /* exit if saw 3 same values */

	return r;
}
# else
static inline unsigned get_HZ_by_waiting(void)
{
	/* Better method? */
	return 100;
}
# endif

static unsigned get_kernel_HZ(void)
{
	if (kernel_HZ)
		return kernel_HZ;

	/* Works for ELF only, Linux 2.4.0+ */
	kernel_HZ = find_elf_note(AT_CLKTCK);
	if (kernel_HZ == (unsigned)-1)
		kernel_HZ = get_HZ_by_waiting();

	G.seconds_since_boot = get_uptime();

	return kernel_HZ;
}
#endif

/* Print value to buf, max size+1 chars (including trailing '\0') */

static void func_user(char *buf, int size, const procps_status_t *ps)
{
#if 1
	safe_strncpy(buf, get_cached_username(ps->uid), size+1);
#else
	/* "compatible" version, but it's larger */
	/* procps 2.18 shows numeric UID if name overflows the field */
	/* TODO: get_cached_username() returns numeric string if
	 * user has no passwd record, we will display it
	 * left-justified here; too long usernames are shown
	 * as _right-justified_ IDs. Is it worth fixing? */
	const char *user = get_cached_username(ps->uid);
	if (strlen(user) <= size)
		safe_strncpy(buf, user, size+1);
	else
		sprintf(buf, "%*u", size, (unsigned)ps->uid);
#endif
}

static void func_group(char *buf, int size, const procps_status_t *ps)
{
	safe_strncpy(buf, get_cached_groupname(ps->gid), size+1);
}

static void func_comm(char *buf, int size, const procps_status_t *ps)
{
	safe_strncpy(buf, ps->comm, size+1);
}

static void func_state(char *buf, int size, const procps_status_t *ps)
{
	safe_strncpy(buf, ps->state, size+1);
}

static void func_args(char *buf, int size, const procps_status_t *ps)
{
	read_cmdline(buf, size+1, ps->pid, ps->comm);
}

static void func_pid(char *buf, int size, const procps_status_t *ps)
{
	sprintf(buf, "%*u", size, ps->pid);
}

static void func_ppid(char *buf, int size, const procps_status_t *ps)
{
	sprintf(buf, "%*u", size, ps->ppid);
}

static void func_pgid(char *buf, int size, const procps_status_t *ps)
{
	sprintf(buf, "%*u", size, ps->pgid);
}

static void func_sid(char *buf, int size, const procps_status_t *ps)
{
	sprintf(buf, "%*u", size, ps->sid);
}

static void put_lu(char *buf, int size, unsigned long u)
{
	char buf4[5];

	/* see http://en.wikipedia.org/wiki/Tera */
	smart_ulltoa4(u, buf4, " mgtpezy")[0] = '\0';
	sprintf(buf, "%.*s", size, buf4);
}

static void func_vsz(char *buf, int size, const procps_status_t *ps)
{
	put_lu(buf, size, ps->vsz);
}

static void func_rss(char *buf, int size, const procps_status_t *ps)
{
	put_lu(buf, size, ps->rss);
}

static void func_tty(char *buf, int size, const procps_status_t *ps)
{
	buf[0] = '?';
	buf[1] = '\0';
	if (ps->tty_major) /* tty field of "0" means "no tty" */
		snprintf(buf, size+1, "%u,%u", ps->tty_major, ps->tty_minor);
}

#if ENABLE_FEATURE_PS_ADDITIONAL_COLUMNS

static void func_rgroup(char *buf, int size, const procps_status_t *ps)
{
	safe_strncpy(buf, get_cached_groupname(ps->rgid), size+1);
}

static void func_ruser(char *buf, int size, const procps_status_t *ps)
{
	safe_strncpy(buf, get_cached_username(ps->ruid), size+1);
}

static void func_nice(char *buf, int size, const procps_status_t *ps)
{
	sprintf(buf, "%*d", size, ps->niceness);
}

#endif

#if ENABLE_FEATURE_PS_TIME

static void func_etime(char *buf, int size, const procps_status_t *ps)
{
	/* elapsed time [[dd-]hh:]mm:ss; here only mm:ss */
	unsigned long mm;
	unsigned ss;

	mm = ps->start_time / get_kernel_HZ();
	/* must be after get_kernel_HZ()! */
	mm = G.seconds_since_boot - mm;
	ss = mm % 60;
	mm /= 60;
	snprintf(buf, size+1, "%3lu:%02u", mm, ss);
}

static void func_time(char *buf, int size, const procps_status_t *ps)
{
	/* cumulative time [[dd-]hh:]mm:ss; here only mm:ss */
	unsigned long mm;
	unsigned ss;

	mm = (ps->utime + ps->stime) / get_kernel_HZ();
	ss = mm % 60;
	mm /= 60;
	snprintf(buf, size+1, "%3lu:%02u", mm, ss);
}

#endif

#if ENABLE_SELINUX
static void func_label(char *buf, int size, const procps_status_t *ps)
{
	safe_strncpy(buf, ps->context ? ps->context : "unknown", size+1);
}
#endif

/*
static void func_pcpu(char *buf, int size, const procps_status_t *ps)
{
}
*/

static const ps_out_t out_spec[] = {
/* Mandated by http://pubs.opengroup.org/onlinepubs/9699919799/utilities/ps.html: */
	{ 8                  , "user"  ,"USER"   ,func_user  ,PSSCAN_UIDGID  },
	{ 8                  , "group" ,"GROUP"  ,func_group ,PSSCAN_UIDGID  },
	{ 16                 , "comm"  ,"COMMAND",func_comm  ,PSSCAN_COMM    },
	{ MAX_WIDTH          , "args"  ,"COMMAND",func_args  ,PSSCAN_COMM    },
	{ 5                  , "pid"   ,"PID"    ,func_pid   ,PSSCAN_PID     },
	{ 5                  , "ppid"  ,"PPID"   ,func_ppid  ,PSSCAN_PPID    },
	{ 5                  , "pgid"  ,"PGID"   ,func_pgid  ,PSSCAN_PGID    },
#if ENABLE_FEATURE_PS_TIME
	{ sizeof("ELAPSED")-1, "etime" ,"ELAPSED",func_etime ,PSSCAN_START_TIME },
#endif
#if ENABLE_FEATURE_PS_ADDITIONAL_COLUMNS
	{ 5                  , "nice"  ,"NI"     ,func_nice  ,PSSCAN_NICE    },
	{ 8                  , "rgroup","RGROUP" ,func_rgroup,PSSCAN_RUIDGID },
	{ 8                  , "ruser" ,"RUSER"  ,func_ruser ,PSSCAN_RUIDGID },
//	{ 5                  , "pcpu"  ,"%CPU"   ,func_pcpu  ,PSSCAN_        },
#endif
#if ENABLE_FEATURE_PS_TIME
	{ 6                  , "time"  ,"TIME"   ,func_time  ,PSSCAN_STIME | PSSCAN_UTIME },
#endif
	{ 6                  , "tty"   ,"TT"     ,func_tty   ,PSSCAN_TTY     },
	{ 4                  , "vsz"   ,"VSZ"    ,func_vsz   ,PSSCAN_VSZ     },
/* Not mandated, but useful: */
	{ 5                  , "sid"   ,"SID"    ,func_sid   ,PSSCAN_SID     },
	{ 4                  , "stat"  ,"STAT"   ,func_state ,PSSCAN_STATE   },
	{ 4                  , "rss"   ,"RSS"    ,func_rss   ,PSSCAN_RSS     },
#if ENABLE_SELINUX
	{ 35                 , "label" ,"LABEL"  ,func_label ,PSSCAN_CONTEXT },
#endif
};

static ps_out_t* new_out_t(void)
{
	out = xrealloc_vector(out, 2, out_cnt);
	return &out[out_cnt++];
}

static const ps_out_t* find_out_spec(const char *name)
{
	unsigned i;
	char buf[ARRAY_SIZE(out_spec)*7 + 1];
	char *p = buf;

	for (i = 0; i < ARRAY_SIZE(out_spec); i++) {
		if (strncmp(name, out_spec[i].name6, 6) == 0)
			return &out_spec[i];
		p += sprintf(p, "%.6s,", out_spec[i].name6);
	}
	p[-1] = '\0';
	bb_error_msg_and_die("bad -o argument '%s', supported arguments: %s", name, buf);
}

static void parse_o(char* opt)
{
	ps_out_t* new;
	// POSIX: "-o is blank- or comma-separated list" (FIXME)
	char *comma, *equal;
	while (1) {
		comma = strchr(opt, ',');
		equal = strchr(opt, '=');
		if (comma && (!equal || equal > comma)) {
			*comma = '\0';
			*new_out_t() = *find_out_spec(opt);
			*comma = ',';
			opt = comma + 1;
			continue;
		}
		break;
	}
	// opt points to last spec in comma separated list.
	// This one can have =HEADER part.
	new = new_out_t();
	if (equal)
		*equal = '\0';
	*new = *find_out_spec(opt);
	if (equal) {
		*equal = '=';
		new->header = equal + 1;
		// POSIX: the field widths shall be ... at least as wide as
		// the header text (default or overridden value).
		// If the header text is null, such as -o user=,
		// the field width shall be at least as wide as the
		// default header text
		if (new->header[0]) {
			new->width = strlen(new->header);
			print_header = 1;
		}
	} else
		print_header = 1;
}

static void alloc_line_buffer(void)
{
	int i;
	int width = 0;
	for (i = 0; i < out_cnt; i++) {
		need_flags |= out[i].ps_flags;
		if (out[i].header[0]) {
			print_header = 1;
		}
		width += out[i].width + 1; /* "FIELD " */
		if ((int)(width - terminal_width) > 0) {
			/* The rest does not fit on the screen */
			//out[i].width -= (width - terminal_width - 1);
			out_cnt = i + 1;
			break;
		}
	}
#if ENABLE_SELINUX
	if (!is_selinux_enabled())
		need_flags &= ~PSSCAN_CONTEXT;
#endif
	buffer = xmalloc(width + 1); /* for trailing \0 */
}

static void format_header(void)
{
	int i;
	ps_out_t* op;
	char *p;

	if (!print_header)
		return;
	p = buffer;
	i = 0;
	if (out_cnt) {
		while (1) {
			op = &out[i];
			if (++i == out_cnt) /* do not pad last field */
				break;
			p += sprintf(p, "%-*s ", op->width, op->header);
		}
		strcpy(p, op->header);
	}
	printf("%.*s\n", terminal_width, buffer);
}

static void format_process(const procps_status_t *ps)
{
	int i, len;
	char *p = buffer;
	i = 0;
	if (out_cnt) while (1) {
		out[i].f(p, out[i].width, ps);
		// POSIX: Any field need not be meaningful in all
		// implementations. In such a case a hyphen ( '-' )
		// should be output in place of the field value.
		if (!p[0]) {
			p[0] = '-';
			p[1] = '\0';
		}
		len = strlen(p);
		p += len;
		len = out[i].width - len + 1;
		if (++i == out_cnt) /* do not pad last field */
			break;
		p += sprintf(p, "%*s", len, "");
	}
	printf("%.*s\n", terminal_width, buffer);
}

#if ENABLE_SELINUX
# define SELINUX_O_PREFIX "label,"
# define DEFAULT_O_STR    (SELINUX_O_PREFIX "pid,user" IF_FEATURE_PS_TIME(",time") ",args")
#else
# define DEFAULT_O_STR    ("pid,user" IF_FEATURE_PS_TIME(",time") ",args")
#endif

int ps_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int ps_main(int argc UNUSED_PARAM, char **argv)
{
	procps_status_t *p;
	llist_t* opt_o = NULL;
	char default_o[sizeof(DEFAULT_O_STR)];
#if ENABLE_SELINUX || ENABLE_FEATURE_SHOW_THREADS
	int opt;
#endif
	enum {
		OPT_Z = (1 << 0),
		OPT_o = (1 << 1),
		OPT_a = (1 << 2),
		OPT_A = (1 << 3),
		OPT_d = (1 << 4),
		OPT_e = (1 << 5),
		OPT_f = (1 << 6),
		OPT_l = (1 << 7),
		OPT_T = (1 << 8) * ENABLE_FEATURE_SHOW_THREADS,
	};

	INIT_G();

	// POSIX:
	// -a  Write information for all processes associated with terminals
	//     Implementations may omit session leaders from this list
	// -A  Write information for all processes
	// -d  Write information for all processes, except session leaders
	// -e  Write information for all processes (equivalent to -A)
	// -f  Generate a full listing
	// -l  Generate a long listing
	// -o col1,col2,col3=header
	//     Select which columns to display
	/* We allow (and ignore) most of the above. FIXME.
	 * -T is picked for threads (POSIX hasn't standardized it).
	 * procps v3.2.7 supports -T and shows tids as SPID column,
	 * it also supports -L where it shows tids as LWP column.
	 */
#if ENABLE_SELINUX || ENABLE_FEATURE_SHOW_THREADS
	opt =
#endif
		getopt32(argv, "Zo:*aAdefl"IF_FEATURE_SHOW_THREADS("T"), &opt_o);

	if (opt_o) {
		do {
			parse_o(llist_pop(&opt_o));
		} while (opt_o);
	} else {
		/* Below: parse_o() needs char*, NOT const char*,
		 * can't pass it constant string. Need to make a copy first.
		 */
#if ENABLE_SELINUX
		if (!(opt & OPT_Z) || !is_selinux_enabled()) {
			/* no -Z or no SELinux: do not show LABEL */
			strcpy(default_o, DEFAULT_O_STR + sizeof(SELINUX_O_PREFIX)-1);
		} else
#endif
		{
			strcpy(default_o, DEFAULT_O_STR);
		}
		parse_o(default_o);
	}
#if ENABLE_FEATURE_SHOW_THREADS
	if (opt & OPT_T)
		need_flags |= PSSCAN_TASKS;
#endif

	/* Was INT_MAX, but some libc's go belly up with printf("%.*s")
	 * and such large widths */
	terminal_width = MAX_WIDTH;
	if (isatty(1)) {
		terminal_width = get_terminal_width(0);
		if (--terminal_width > MAX_WIDTH)
			terminal_width = MAX_WIDTH;
	}
	alloc_line_buffer();
	format_header();

	p = NULL;
	while ((p = procps_scan(p, need_flags)) != NULL) {
		format_process(p);
	}

	return EXIT_SUCCESS;
}


#else /* !ENABLE_DESKTOP */


int ps_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int ps_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
{
	procps_status_t *p;
	int psscan_flags = PSSCAN_PID | PSSCAN_UIDGID
			| PSSCAN_STATE | PSSCAN_VSZ | PSSCAN_COMM;
	unsigned terminal_width IF_NOT_FEATURE_PS_WIDE(= 79);
	enum {
		OPT_Z = (1 << 0) * ENABLE_SELINUX,
		OPT_T = (1 << ENABLE_SELINUX) * ENABLE_FEATURE_SHOW_THREADS,
		OPT_l = (1 << ENABLE_SELINUX) * (1 << ENABLE_FEATURE_SHOW_THREADS) * ENABLE_FEATURE_PS_LONG,
	};
#if ENABLE_FEATURE_PS_LONG
	time_t now = now; /* for compiler */
	unsigned long uptime = uptime;
#endif
	/* If we support any options, parse argv */
#if ENABLE_SELINUX || ENABLE_FEATURE_SHOW_THREADS || ENABLE_FEATURE_PS_WIDE || ENABLE_FEATURE_PS_LONG
	int opts = 0;
# if ENABLE_FEATURE_PS_WIDE
	/* -w is a bit complicated */
	int w_count = 0;
	make_all_argv_opts(argv);
	opt_complementary = "ww";
	opts = getopt32(argv, IF_SELINUX("Z")IF_FEATURE_SHOW_THREADS("T")IF_FEATURE_PS_LONG("l")
					"w", &w_count);
	/* if w is given once, GNU ps sets the width to 132,
	 * if w is given more than once, it is "unlimited"
	 */
	if (w_count) {
		terminal_width = (w_count == 1) ? 132 : MAX_WIDTH;
	} else {
		terminal_width = get_terminal_width(0);
		/* Go one less... */
		if (--terminal_width > MAX_WIDTH)
			terminal_width = MAX_WIDTH;
	}
# else
	/* -w is not supported, only -Z and/or -T */
	make_all_argv_opts(argv);
	opts = getopt32(argv, IF_SELINUX("Z")IF_FEATURE_SHOW_THREADS("T")IF_FEATURE_PS_LONG("l"));
# endif

# if ENABLE_SELINUX
	if ((opts & OPT_Z) && is_selinux_enabled()) {
		psscan_flags = PSSCAN_PID | PSSCAN_CONTEXT
				| PSSCAN_STATE | PSSCAN_COMM;
		puts("  PID CONTEXT                          STAT COMMAND");
	} else
# endif
	if (opts & OPT_l) {
		psscan_flags = PSSCAN_STATE | PSSCAN_UIDGID | PSSCAN_PID | PSSCAN_PPID
			| PSSCAN_TTY | PSSCAN_STIME | PSSCAN_UTIME | PSSCAN_COMM
			| PSSCAN_VSZ | PSSCAN_RSS;
/* http://pubs.opengroup.org/onlinepubs/9699919799/utilities/ps.html
 * mandates for -l:
 * -F     Flags (?)
 * S      State
 * UID,PID,PPID
 * -C     CPU usage
 * -PRI   The priority of the process; higher numbers mean lower priority
 * -NI    Nice value
 * -ADDR  The address of the process (?)
 * SZ     The size in blocks of the core image
 * -WCHAN The event for which the process is waiting or sleeping
 * TTY
 * TIME   The cumulative execution time
 * CMD
 * We don't show fields marked with '-'.
 * We show VSZ and RSS instead of SZ.
 * We also show STIME (standard says that -f shows it, -l doesn't).
 */
		puts("S   UID   PID  PPID   VSZ   RSS TTY   STIME TIME     CMD");
# if ENABLE_FEATURE_PS_LONG
		now = time(NULL);
		uptime = get_uptime();
# endif
	}
	else {
		puts("  PID USER       VSZ STAT COMMAND");
	}
	if (opts & OPT_T) {
		psscan_flags |= PSSCAN_TASKS;
	}
#endif

	p = NULL;
	while ((p = procps_scan(p, psscan_flags)) != NULL) {
		int len;
#if ENABLE_SELINUX
		if (psscan_flags & PSSCAN_CONTEXT) {
			len = printf("%5u %-32.32s %s  ",
					p->pid,
					p->context ? p->context : "unknown",
					p->state);
		} else
#endif
		{
			char buf6[6];
			smart_ulltoa5(p->vsz, buf6, " mgtpezy")[0] = '\0';
#if ENABLE_FEATURE_PS_LONG
			if (opts & OPT_l) {
				char bufr[6], stime_str[6];
				char tty[2 * sizeof(int)*3 + 2];
				char *endp;
				unsigned sut = (p->stime + p->utime) / 100;
				unsigned elapsed = uptime - (p->start_time / 100);
				time_t start = now - elapsed;
				struct tm *tm = localtime(&start);

				smart_ulltoa5(p->rss, bufr, " mgtpezy")[0] = '\0';

				if (p->tty_major == 136)
					/* It should be pts/N, not ptsN, but N > 9
					 * will overflow field width...
					 */
					endp = stpcpy(tty, "pts");
				else
				if (p->tty_major == 4) {
					endp = stpcpy(tty, "tty");
					if (p->tty_minor >= 64) {
						p->tty_minor -= 64;
						*endp++ = 'S';
					}
				}
				else
					endp = tty + sprintf(tty, "%d:", p->tty_major);
				strcpy(endp, utoa(p->tty_minor));

				strftime(stime_str, 6, (elapsed >= (24 * 60 * 60)) ? "%b%d" : "%H:%M", tm);
				stime_str[5] = '\0';
				//            S  UID PID PPID VSZ RSS TTY STIME TIME        CMD
				len = printf("%c %5u %5u %5u %5s %5s %-5s %s %02u:%02u:%02u ",
					p->state[0], p->uid, p->pid, p->ppid, buf6, bufr, tty,
					stime_str, sut / 3600, (sut % 3600) / 60, sut % 60);
			} else
#endif
			{
				const char *user = get_cached_username(p->uid);
				len = printf("%5u %-8.8s %s %s  ",
					p->pid, user, buf6, p->state);
			}
		}

		{
			int sz = terminal_width - len;
			if (sz >= 0) {
				char buf[sz + 1];
				read_cmdline(buf, sz, p->pid, p->comm);
				puts(buf);
			}
		}
	}
	if (ENABLE_FEATURE_CLEAN_UP)
		clear_username_cache();
	return EXIT_SUCCESS;
}

#endif /* !ENABLE_DESKTOP */