1 /* vi: set sw=4 ts=4: */
2 /*
3  * ipcs.c -- provides information on allocated ipc resources.
4  *
5  * 01 Sept 2004 - Rodney Radford <rradford@mindspring.com>
6  * Adapted for busybox from util-linux-2.12a.
7  *
8  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
9  */
10 //config:config IPCS
11 //config:	bool "ipcs (11 kb)"
12 //config:	default y
13 //config:	help
14 //config:	The ipcs utility is used to provide information on the currently
15 //config:	allocated System V interprocess (IPC) objects in the system.
16 
17 //applet:IF_IPCS(APPLET_NOEXEC(ipcs, ipcs, BB_DIR_USR_BIN, BB_SUID_DROP, ipcs))
18 
19 //kbuild:lib-$(CONFIG_IPCS) += ipcs.o
20 
21 /* X/OPEN tells us to use <sys/{types,ipc,sem}.h> for semctl() */
22 /* X/OPEN tells us to use <sys/{types,ipc,msg}.h> for msgctl() */
23 /* X/OPEN tells us to use <sys/{types,ipc,shm}.h> for shmctl() */
24 #include <sys/types.h>
25 #include <sys/ipc.h>
26 #include <sys/sem.h>
27 #include <sys/msg.h>
28 #include <sys/shm.h>
29 
30 #include "libbb.h"
31 
32 /*-------------------------------------------------------------------*/
33 /* SHM_DEST and SHM_LOCKED are defined in kernel headers,
34    but inside #ifdef __KERNEL__ ... #endif */
35 #ifndef SHM_DEST
36 /* shm_mode upper byte flags */
37 #define SHM_DEST        01000	/* segment will be destroyed on last detach */
38 #define SHM_LOCKED      02000	/* segment will not be swapped */
39 #endif
40 
41 /* For older kernels the same holds for the defines below */
42 #ifndef MSG_STAT
43 #define MSG_STAT	11
44 #define MSG_INFO	12
45 #endif
46 
47 #ifndef SHM_STAT
48 #define SHM_STAT        13
49 #define SHM_INFO        14
50 struct shm_info {
51 	int used_ids;
52 	unsigned long shm_tot;		/* total allocated shm */
53 	unsigned long shm_rss;		/* total resident shm */
54 	unsigned long shm_swp;		/* total swapped shm */
55 	unsigned long swap_attempts;
56 	unsigned long swap_successes;
57 };
58 #endif
59 
60 #ifndef SEM_STAT
61 #define SEM_STAT	18
62 #define SEM_INFO	19
63 #endif
64 
65 /* Some versions of libc only define IPC_INFO when __USE_GNU is defined. */
66 #ifndef IPC_INFO
67 #define IPC_INFO        3
68 #endif
69 /*-------------------------------------------------------------------*/
70 
71 /* The last arg of semctl is a union semun, but where is it defined?
72    X/OPEN tells us to define it ourselves, but until recently
73    Linux include files would also define it. */
74 #if defined(__GNU_LIBRARY__) && !defined(_SEM_SEMUN_UNDEFINED)
75 /* union semun is defined by including <sys/sem.h> */
76 #else
77 /* according to X/OPEN we have to define it ourselves */
78 union semun {
79 	int val;
80 	struct semid_ds *buf;
81 	unsigned short *array;
82 	struct seminfo *__buf;
83 };
84 #endif
85 
86 /* X/OPEN (Jan 1987) does not define fields key, seq in struct ipc_perm;
87    libc 4/5 does not mention struct ipc_term at all, but includes
88    <linux/ipc.h>, which defines a struct ipc_perm with such fields.
89    glibc-1.09 has no support for sysv ipc.
90    glibc 2 uses __key, __seq */
91 #if defined(__GNU_LIBRARY__) && __GNU_LIBRARY__ > 1
92 #define KEY __key
93 #else
94 #define KEY key
95 #endif
96 
97 #define LIMITS 1
98 #define STATUS 2
99 #define CREATOR 3
100 #define TIME 4
101 #define PID 5
102 
print_perms(int id,struct ipc_perm * ipcp)103 static void print_perms(int id, struct ipc_perm *ipcp)
104 {
105 	struct passwd *pw;
106 	struct group *gr;
107 
108 	printf("%-10d %-10o", id, ipcp->mode & 0777);
109 
110 	pw = getpwuid(ipcp->cuid);
111 	if (pw)	printf(" %-10s", pw->pw_name);
112 	else	printf(" %-10d", ipcp->cuid);
113 	gr = getgrgid(ipcp->cgid);
114 	if (gr)	printf(" %-10s", gr->gr_name);
115 	else	printf(" %-10d", ipcp->cgid);
116 
117 	pw = getpwuid(ipcp->uid);
118 	if (pw)	printf(" %-10s", pw->pw_name);
119 	else	printf(" %-10d", ipcp->uid);
120 	gr = getgrgid(ipcp->gid);
121 	if (gr)	printf(" %-10s\n", gr->gr_name);
122 	else	printf(" %-10d\n", ipcp->gid);
123 }
124 
do_shm(int format)125 static NOINLINE void do_shm(int format)
126 {
127 	int maxid, shmid, id;
128 	struct shmid_ds shmseg;
129 	struct shm_info shm_info;
130 	struct shminfo shminfo;
131 	struct ipc_perm *ipcp = &shmseg.shm_perm;
132 	struct passwd *pw;
133 
134 	maxid = shmctl(0, SHM_INFO, (struct shmid_ds *) (void *) &shm_info);
135 	if (maxid < 0) {
136 		printf("kernel not configured for %s\n", "shared memory");
137 		return;
138 	}
139 
140 	switch (format) {
141 	case LIMITS:
142 		printf("------ Shared Memory %s --------\n", "Limits");
143 		if ((shmctl(0, IPC_INFO, (struct shmid_ds *) (void *) &shminfo)) < 0)
144 			return;
145 		/* glibc 2.1.3 and all earlier libc's have ints as fields
146 		 * of struct shminfo; glibc 2.1.91 has unsigned long; ach */
147 		printf("max number of segments = %lu\n"
148 				"max seg size (kbytes) = %lu\n"
149 				"max total shared memory (pages) = %lu\n"
150 				"min seg size (bytes) = %lu\n",
151 				(unsigned long) shminfo.shmmni,
152 				(unsigned long) (shminfo.shmmax >> 10),
153 				(unsigned long) shminfo.shmall,
154 				(unsigned long) shminfo.shmmin);
155 		return;
156 
157 	case STATUS:
158 		printf("------ Shared Memory %s --------\n", "Status");
159 		printf("segments allocated %d\n"
160 				"pages allocated %lu\n"
161 				"pages resident  %lu\n"
162 				"pages swapped   %lu\n"
163 				"Swap performance: %lu attempts\t%lu successes\n",
164 				shm_info.used_ids,
165 				shm_info.shm_tot,
166 				shm_info.shm_rss,
167 				shm_info.shm_swp,
168 				shm_info.swap_attempts, shm_info.swap_successes);
169 		return;
170 
171 	case CREATOR:
172 		printf("------ Shared Memory %s --------\n", "Segment Creators/Owners");
173 		printf("%-10s %-10s %-10s %-10s %-10s %-10s\n",
174 				"shmid", "perms", "cuid", "cgid", "uid", "gid");
175 		break;
176 
177 	case TIME:
178 		printf("------ Shared Memory %s --------\n", "Attach/Detach/Change Times");
179 		printf("%-10s %-10s %-20s %-20s %-20s\n",
180 				"shmid", "owner", "attached", "detached", "changed");
181 		break;
182 
183 	case PID:
184 		printf("------ Shared Memory %s --------\n", "Creator/Last-op");
185 		printf("%-10s %-10s %-10s %-10s\n",
186 				"shmid", "owner", "cpid", "lpid");
187 		break;
188 
189 	default:
190 		printf("------ Shared Memory %s --------\n", "Segments");
191 		printf("%-10s %-10s %-10s %-10s %-10s %-10s %-12s\n",
192 				"key", "shmid", "owner", "perms", "bytes", "nattch",
193 				"status");
194 		break;
195 	}
196 
197 	for (id = 0; id <= maxid; id++) {
198 		shmid = shmctl(id, SHM_STAT, &shmseg);
199 		if (shmid < 0)
200 			continue;
201 		if (format == CREATOR) {
202 			print_perms(shmid, ipcp);
203 			continue;
204 		}
205 		pw = getpwuid(ipcp->uid);
206 		switch (format) {
207 		case TIME:
208 			if (pw)
209 				printf("%-10d %-10.10s", shmid, pw->pw_name);
210 			else
211 				printf("%-10d %-10d", shmid, ipcp->uid);
212 			/* ctime uses static buffer: use separate calls */
213 			printf(" %-20.16s", shmseg.shm_atime
214 					? ctime(&shmseg.shm_atime) + 4 : "Not set");
215 			printf(" %-20.16s", shmseg.shm_dtime
216 					? ctime(&shmseg.shm_dtime) + 4 : "Not set");
217 			printf(" %-20.16s\n", shmseg.shm_ctime
218 					? ctime(&shmseg.shm_ctime) + 4 : "Not set");
219 			break;
220 		case PID:
221 			if (pw)
222 				printf("%-10d %-10.10s", shmid, pw->pw_name);
223 			else
224 				printf("%-10d %-10d", shmid, ipcp->uid);
225 			printf(" %-10d %-10d\n", shmseg.shm_cpid, shmseg.shm_lpid);
226 			break;
227 
228 		default:
229 			printf("0x%08x ", ipcp->KEY);
230 			if (pw)
231 				printf("%-10d %-10.10s", shmid, pw->pw_name);
232 			else
233 				printf("%-10d %-10d", shmid, ipcp->uid);
234 			printf(" %-10o %-10lu %-10ld %-6s %-6s\n", ipcp->mode & 0777,
235 					/*
236 					 * earlier: int, Austin has size_t
237 					 */
238 					(unsigned long) shmseg.shm_segsz,
239 					/*
240 					 * glibc-2.1.3 and earlier has unsigned short;
241 					 * Austin has shmatt_t
242 					 */
243 					(long) shmseg.shm_nattch,
244 					ipcp->mode & SHM_DEST ? "dest" : " ",
245 					ipcp->mode & SHM_LOCKED ? "locked" : " ");
246 			break;
247 		}
248 	}
249 }
250 
do_sem(int format)251 static NOINLINE void do_sem(int format)
252 {
253 	int maxid, semid, id;
254 	struct semid_ds semary;
255 	struct seminfo seminfo;
256 	struct ipc_perm *ipcp = &semary.sem_perm;
257 	struct passwd *pw;
258 	union semun arg;
259 
260 	arg.array = (unsigned short *) (void *) &seminfo;
261 	maxid = semctl(0, 0, SEM_INFO, arg);
262 	if (maxid < 0) {
263 		printf("kernel not configured for %s\n", "semaphores");
264 		return;
265 	}
266 
267 	switch (format) {
268 	case LIMITS:
269 		printf("------ Semaphore %s --------\n", "Limits");
270 		arg.array = (unsigned short *) (void *) &seminfo;	/* damn union */
271 		if ((semctl(0, 0, IPC_INFO, arg)) < 0)
272 			return;
273 		printf("max number of arrays = %d\n"
274 				"max semaphores per array = %d\n"
275 				"max semaphores system wide = %d\n"
276 				"max ops per semop call = %d\n"
277 				"semaphore max value = %d\n",
278 				seminfo.semmni,
279 				seminfo.semmsl,
280 				seminfo.semmns, seminfo.semopm, seminfo.semvmx);
281 		return;
282 
283 	case STATUS:
284 		printf("------ Semaphore %s --------\n", "Status");
285 		printf("used arrays = %d\n"
286 				"allocated semaphores = %d\n",
287 				seminfo.semusz, seminfo.semaem);
288 		return;
289 
290 	case CREATOR:
291 		printf("------ Semaphore %s --------\n", "Arrays Creators/Owners");
292 		printf("%-10s %-10s %-10s %-10s %-10s %-10s\n",
293 				"semid", "perms", "cuid", "cgid", "uid", "gid");
294 		break;
295 
296 	case TIME:
297 		printf("------ Shared Memory %s --------\n", "Operation/Change Times");
298 		printf("%-8s %-10s %-26.24s %-26.24s\n",
299 				"shmid", "owner", "last-op", "last-changed");
300 		break;
301 
302 	case PID:
303 		break;
304 
305 	default:
306 		printf("------ Semaphore %s --------\n", "Arrays");
307 		printf("%-10s %-10s %-10s %-10s %-10s\n",
308 				"key", "semid", "owner", "perms", "nsems");
309 		break;
310 	}
311 
312 	for (id = 0; id <= maxid; id++) {
313 		arg.buf = (struct semid_ds *) &semary;
314 		semid = semctl(id, 0, SEM_STAT, arg);
315 		if (semid < 0)
316 			continue;
317 		if (format == CREATOR) {
318 			print_perms(semid, ipcp);
319 			continue;
320 		}
321 		pw = getpwuid(ipcp->uid);
322 		switch (format) {
323 		case TIME:
324 			if (pw)
325 				printf("%-8d %-10.10s", semid, pw->pw_name);
326 			else
327 				printf("%-8d %-10d", semid, ipcp->uid);
328 			/* ctime uses static buffer: use separate calls */
329 			printf("  %-26.24s", semary.sem_otime
330 					? ctime(&semary.sem_otime) : "Not set");
331 			printf(" %-26.24s\n", semary.sem_ctime
332 					? ctime(&semary.sem_ctime) : "Not set");
333 			break;
334 		case PID:
335 			break;
336 
337 		default:
338 			printf("0x%08x ", ipcp->KEY);
339 			if (pw)
340 				printf("%-10d %-10.9s", semid, pw->pw_name);
341 			else
342 				printf("%-10d %-9d", semid, ipcp->uid);
343 			printf(" %-10o %-10ld\n", ipcp->mode & 0777,
344 					/*
345 					 * glibc-2.1.3 and earlier has unsigned short;
346 					 * glibc-2.1.91 has variation between
347 					 * unsigned short and unsigned long
348 					 * Austin prescribes unsigned short.
349 					 */
350 					(long) semary.sem_nsems);
351 			break;
352 		}
353 	}
354 }
355 
do_msg(int format)356 static NOINLINE void do_msg(int format)
357 {
358 	int maxid, msqid, id;
359 	struct msqid_ds msgque;
360 	struct msginfo msginfo;
361 	struct ipc_perm *ipcp = &msgque.msg_perm;
362 	struct passwd *pw;
363 
364 	maxid = msgctl(0, MSG_INFO, (struct msqid_ds *) (void *) &msginfo);
365 	if (maxid < 0) {
366 		printf("kernel not configured for %s\n", "message queues");
367 		return;
368 	}
369 
370 	switch (format) {
371 	case LIMITS:
372 		if ((msgctl(0, IPC_INFO, (struct msqid_ds *) (void *) &msginfo)) < 0)
373 			return;
374 		printf("------ Message%s --------\n", "s: Limits");
375 		printf("max queues system wide = %d\n"
376 				"max size of message (bytes) = %d\n"
377 				"default max size of queue (bytes) = %d\n",
378 				msginfo.msgmni, msginfo.msgmax, msginfo.msgmnb);
379 		return;
380 
381 	case STATUS:
382 		printf("------ Message%s --------\n", "s: Status");
383 		printf("allocated queues = %d\n"
384 				"used headers = %d\n"
385 				"used space = %d bytes\n",
386 				msginfo.msgpool, msginfo.msgmap, msginfo.msgtql);
387 		return;
388 
389 	case CREATOR:
390 		printf("------ Message%s --------\n", " Queues: Creators/Owners");
391 		printf("%-10s %-10s %-10s %-10s %-10s %-10s\n",
392 				"msqid", "perms", "cuid", "cgid", "uid", "gid");
393 		break;
394 
395 	case TIME:
396 		printf("------ Message%s --------\n", " Queues Send/Recv/Change Times");
397 		printf("%-8s %-10s %-20s %-20s %-20s\n",
398 				"msqid", "owner", "send", "recv", "change");
399 		break;
400 
401 	case PID:
402 		printf("------ Message%s --------\n", " Queues PIDs");
403 		printf("%-10s %-10s %-10s %-10s\n",
404 				"msqid", "owner", "lspid", "lrpid");
405 		break;
406 
407 	default:
408 		printf("------ Message%s --------\n", " Queues");
409 		printf("%-10s %-10s %-10s %-10s %-12s %-12s\n",
410 				"key", "msqid", "owner", "perms", "used-bytes", "messages");
411 		break;
412 	}
413 
414 	for (id = 0; id <= maxid; id++) {
415 		msqid = msgctl(id, MSG_STAT, &msgque);
416 		if (msqid < 0)
417 			continue;
418 		if (format == CREATOR) {
419 			print_perms(msqid, ipcp);
420 			continue;
421 		}
422 		pw = getpwuid(ipcp->uid);
423 		switch (format) {
424 		case TIME:
425 			if (pw)
426 				printf("%-8d %-10.10s", msqid, pw->pw_name);
427 			else
428 				printf("%-8d %-10d", msqid, ipcp->uid);
429 			printf(" %-20.16s", msgque.msg_stime
430 					? ctime(&msgque.msg_stime) + 4 : "Not set");
431 			printf(" %-20.16s", msgque.msg_rtime
432 					? ctime(&msgque.msg_rtime) + 4 : "Not set");
433 			printf(" %-20.16s\n", msgque.msg_ctime
434 					? ctime(&msgque.msg_ctime) + 4 : "Not set");
435 			break;
436 		case PID:
437 			if (pw)
438 				printf("%-8d %-10.10s", msqid, pw->pw_name);
439 			else
440 				printf("%-8d %-10d", msqid, ipcp->uid);
441 			printf("  %5d     %5d\n", msgque.msg_lspid, msgque.msg_lrpid);
442 			break;
443 
444 		default:
445 			printf("0x%08x ", ipcp->KEY);
446 			if (pw)
447 				printf("%-10d %-10.10s", msqid, pw->pw_name);
448 			else
449 				printf("%-10d %-10d", msqid, ipcp->uid);
450 			printf(" %-10o %-12ld %-12ld\n", ipcp->mode & 0777,
451 					/*
452 					 * glibc-2.1.3 and earlier has unsigned short;
453 					 * glibc-2.1.91 has variation between
454 					 * unsigned short, unsigned long
455 					 * Austin has msgqnum_t
456 					 */
457 					(long) msgque.msg_cbytes, (long) msgque.msg_qnum);
458 			break;
459 		}
460 	}
461 }
462 
print_shm(int shmid)463 static void print_shm(int shmid)
464 {
465 	struct shmid_ds shmds;
466 	struct ipc_perm *ipcp = &shmds.shm_perm;
467 
468 	if (shmctl(shmid, IPC_STAT, &shmds) == -1) {
469 		bb_simple_perror_msg("shmctl");
470 		return;
471 	}
472 
473 	printf("\nShared memory Segment shmid=%d\n"
474 			"uid=%d\tgid=%d\tcuid=%d\tcgid=%d\n"
475 			"mode=%#o\taccess_perms=%#o\n"
476 			"bytes=%ld\tlpid=%d\tcpid=%d\tnattch=%ld\n",
477 			shmid,
478 			ipcp->uid, ipcp->gid, ipcp->cuid, ipcp->cgid,
479 			ipcp->mode, ipcp->mode & 0777,
480 			(long) shmds.shm_segsz, shmds.shm_lpid, shmds.shm_cpid,
481 			(long) shmds.shm_nattch);
482 	printf("att_time=%-26.24s\n",
483 			shmds.shm_atime ? ctime(&shmds.shm_atime) : "Not set");
484 	printf("det_time=%-26.24s\n",
485 			shmds.shm_dtime ? ctime(&shmds.shm_dtime) : "Not set");
486 	printf("change_time=%-26.24s\n\n", ctime(&shmds.shm_ctime));
487 }
488 
print_msg(int msqid)489 static void print_msg(int msqid)
490 {
491 	struct msqid_ds buf;
492 	struct ipc_perm *ipcp = &buf.msg_perm;
493 
494 	if (msgctl(msqid, IPC_STAT, &buf) == -1) {
495 		bb_simple_perror_msg("msgctl");
496 		return;
497 	}
498 
499 	printf("\nMessage Queue msqid=%d\n"
500 			"uid=%d\tgid=%d\tcuid=%d\tcgid=%d\tmode=%#o\n"
501 			"cbytes=%ld\tqbytes=%ld\tqnum=%ld\tlspid=%d\tlrpid=%d\n",
502 			msqid, ipcp->uid, ipcp->gid, ipcp->cuid, ipcp->cgid, ipcp->mode,
503 			/*
504 			 * glibc-2.1.3 and earlier has unsigned short;
505 			 * glibc-2.1.91 has variation between
506 			 * unsigned short, unsigned long
507 			 * Austin has msgqnum_t (for msg_qbytes)
508 			 */
509 			(long) buf.msg_cbytes, (long) buf.msg_qbytes,
510 			(long) buf.msg_qnum, buf.msg_lspid, buf.msg_lrpid);
511 
512 	printf("send_time=%-26.24s\n",
513 			buf.msg_stime ? ctime(&buf.msg_stime) : "Not set");
514 	printf("rcv_time=%-26.24s\n",
515 			buf.msg_rtime ? ctime(&buf.msg_rtime) : "Not set");
516 	printf("change_time=%-26.24s\n\n",
517 			buf.msg_ctime ? ctime(&buf.msg_ctime) : "Not set");
518 }
519 
print_sem(int semid)520 static void print_sem(int semid)
521 {
522 	struct semid_ds semds;
523 	struct ipc_perm *ipcp = &semds.sem_perm;
524 	union semun arg;
525 	unsigned int i;
526 
527 	arg.buf = &semds;
528 	if (semctl(semid, 0, IPC_STAT, arg)) {
529 		bb_simple_perror_msg("semctl");
530 		return;
531 	}
532 
533 	printf("\nSemaphore Array semid=%d\n"
534 			"uid=%d\t gid=%d\t cuid=%d\t cgid=%d\n"
535 			"mode=%#o, access_perms=%#o\n"
536 			"nsems = %ld\n"
537 			"otime = %-26.24s\n",
538 			semid,
539 			ipcp->uid, ipcp->gid, ipcp->cuid, ipcp->cgid,
540 			ipcp->mode, ipcp->mode & 0777,
541 			(long) semds.sem_nsems,
542 			semds.sem_otime ? ctime(&semds.sem_otime) : "Not set");
543 	printf("ctime = %-26.24s\n"
544 			"%-10s %-10s %-10s %-10s %-10s\n",
545 			ctime(&semds.sem_ctime),
546 			"semnum", "value", "ncount", "zcount", "pid");
547 
548 	arg.val = 0;
549 	for (i = 0; i < semds.sem_nsems; i++) {
550 		int val, ncnt, zcnt, pid;
551 
552 		val = semctl(semid, i, GETVAL, arg);
553 		ncnt = semctl(semid, i, GETNCNT, arg);
554 		zcnt = semctl(semid, i, GETZCNT, arg);
555 		pid = semctl(semid, i, GETPID, arg);
556 		if (val < 0 || ncnt < 0 || zcnt < 0 || pid < 0) {
557 			bb_simple_perror_msg_and_die("semctl");
558 		}
559 		printf("%-10u %-10d %-10d %-10d %-10d\n", i, val, ncnt, zcnt, pid);
560 	}
561 	bb_putchar('\n');
562 }
563 
564 //usage:#define ipcs_trivial_usage
565 //usage:       "[[-smq] -i SHMID] | [[-asmq] [-tcplu]]"
566 //usage:#define ipcs_full_usage "\n\n"
567 //usage:       "	-i ID	Show specific resource"
568 //usage:     "\nResource specification:"
569 //usage:     "\n	-m	Shared memory segments"
570 //usage:     "\n	-q	Message queues"
571 //usage:     "\n	-s	Semaphore arrays"
572 //usage:     "\n	-a	All (default)"
573 //usage:     "\nOutput format:"
574 //usage:     "\n	-t	Time"
575 //usage:     "\n	-c	Creator"
576 //usage:     "\n	-p	Pid"
577 //usage:     "\n	-l	Limits"
578 //usage:     "\n	-u	Summary"
579 
580 int ipcs_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
ipcs_main(int argc UNUSED_PARAM,char ** argv)581 int ipcs_main(int argc UNUSED_PARAM, char **argv)
582 {
583 	int format = 0;
584 	unsigned opt;
585 	char *opt_i;
586 
587 	opt = getopt32(argv, "i:aqsmtcplu", &opt_i);
588 #define flag_msg (1<<2)
589 #define flag_sem (1<<3)
590 #define flag_shm (1<<4)
591 	if (opt & (1<<5)) format = TIME; // -t
592 	if (opt & (1<<6)) format = CREATOR; // -c
593 	if (opt & (1<<7)) format = PID; // -p
594 	if (opt & (1<<8)) format = LIMITS; // -l
595 	if (opt & (1<<9)) format = STATUS; // -u
596 
597 	if (opt & (1<<0)) { // -i
598 		int id;
599 
600 		id = xatoi(opt_i);
601 		if (opt & flag_shm) {
602 			print_shm(id);
603 			fflush_stdout_and_exit(EXIT_SUCCESS);
604 		}
605 		if (opt & flag_sem) {
606 			print_sem(id);
607 			fflush_stdout_and_exit(EXIT_SUCCESS);
608 		}
609 		if (opt & flag_msg) {
610 			print_msg(id);
611 			fflush_stdout_and_exit(EXIT_SUCCESS);
612 		}
613 		bb_show_usage();
614 	}
615 
616 	if ((opt & (1<<1)) // -a
617 	 || !(opt & (flag_msg | flag_sem | flag_shm)) // none of -q,-s,-m == all
618 	) {
619 		opt |= flag_msg | flag_sem | flag_shm;
620 	}
621 
622 	bb_putchar('\n');
623 
624 	if (opt & flag_msg) {
625 		do_msg(format);
626 		bb_putchar('\n');
627 	}
628 	if (opt & flag_shm) {
629 		do_shm(format);
630 		bb_putchar('\n');
631 	}
632 	if (opt & flag_sem) {
633 		do_sem(format);
634 		bb_putchar('\n');
635 	}
636 	fflush_stdout_and_exit(EXIT_SUCCESS);
637 }
638