1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1991, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Kenneth Almquist.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #ifndef lint
36 #if 0
37 static char sccsid[] = "@(#)miscbltin.c 8.4 (Berkeley) 5/4/95";
38 #endif
39 #endif /* not lint */
40 #include <sys/cdefs.h>
41 /*
42 * Miscellaneous builtins.
43 */
44
45 #include <sys/types.h>
46 #include <sys/stat.h>
47 #include <sys/time.h>
48 #include <sys/resource.h>
49 #include <unistd.h>
50 #include <errno.h>
51 #include <stdint.h>
52 #include <stdio.h>
53 #include <stdlib.h>
54
55 #include "shell.h"
56 #include "options.h"
57 #include "var.h"
58 #include "output.h"
59 #include "memalloc.h"
60 #include "error.h"
61 #include "mystring.h"
62 #include "syntax.h"
63 #include "trap.h"
64
65 #undef eflag
66
67 #define READ_BUFLEN 1024
68 struct fdctx {
69 int fd;
70 size_t off; /* offset in buf */
71 size_t buflen;
72 char *ep; /* tail pointer */
73 char buf[READ_BUFLEN];
74 };
75
76 static void fdctx_init(int, struct fdctx *);
77 static void fdctx_destroy(struct fdctx *);
78 static ssize_t fdgetc(struct fdctx *, char *);
79 int readcmd(int, char **);
80 int umaskcmd(int, char **);
81 int ulimitcmd(int, char **);
82
83 static void
fdctx_init(int fd,struct fdctx * fdc)84 fdctx_init(int fd, struct fdctx *fdc)
85 {
86 off_t cur;
87
88 /* Check if fd is seekable. */
89 cur = lseek(fd, 0, SEEK_CUR);
90 *fdc = (struct fdctx){
91 .fd = fd,
92 .buflen = (cur != -1) ? READ_BUFLEN : 1,
93 .ep = &fdc->buf[0], /* No data */
94 };
95 }
96
97 static ssize_t
fdgetc(struct fdctx * fdc,char * c)98 fdgetc(struct fdctx *fdc, char *c)
99 {
100 ssize_t nread;
101
102 if (&fdc->buf[fdc->off] == fdc->ep) {
103 nread = read(fdc->fd, fdc->buf, fdc->buflen);
104 if (nread > 0) {
105 fdc->off = 0;
106 fdc->ep = fdc->buf + nread;
107 } else
108 return (nread);
109 }
110 *c = fdc->buf[fdc->off++];
111
112 return (1);
113 }
114
115 static void
fdctx_destroy(struct fdctx * fdc)116 fdctx_destroy(struct fdctx *fdc)
117 {
118 off_t residue;
119
120 if (fdc->buflen > 1) {
121 /*
122 * Reposition the file offset. Here is the layout of buf:
123 *
124 * | off
125 * v
126 * |*****************|-------|
127 * buf ep buf+buflen
128 * |<- residue ->|
129 *
130 * off: current character
131 * ep: offset just after read(2)
132 * residue: length for reposition
133 */
134 residue = (fdc->ep - fdc->buf) - fdc->off;
135 if (residue > 0)
136 (void) lseek(fdc->fd, -residue, SEEK_CUR);
137 }
138 }
139
140 /*
141 * The read builtin. The -r option causes backslashes to be treated like
142 * ordinary characters.
143 *
144 * Note that if IFS=' :' then read x y should work so that:
145 * 'a b' x='a', y='b'
146 * ' a b ' x='a', y='b'
147 * ':b' x='', y='b'
148 * ':' x='', y=''
149 * '::' x='', y=''
150 * ': :' x='', y=''
151 * ':::' x='', y='::'
152 * ':b c:' x='', y='b c:'
153 */
154
155 int
readcmd(int argc __unused,char ** argv __unused)156 readcmd(int argc __unused, char **argv __unused)
157 {
158 char **ap;
159 int backslash;
160 char c;
161 int rflag;
162 char *prompt;
163 const char *ifs;
164 char *p;
165 int startword;
166 int status;
167 int i;
168 int is_ifs;
169 int saveall = 0;
170 ptrdiff_t lastnonifs, lastnonifsws;
171 struct timeval tv;
172 char *tvptr;
173 fd_set ifds;
174 ssize_t nread;
175 int sig;
176 struct fdctx fdctx;
177
178 rflag = 0;
179 prompt = NULL;
180 tv.tv_sec = -1;
181 tv.tv_usec = 0;
182 while ((i = nextopt("erp:t:")) != '\0') {
183 switch(i) {
184 case 'p':
185 prompt = shoptarg;
186 break;
187 case 'e':
188 break;
189 case 'r':
190 rflag = 1;
191 break;
192 case 't':
193 tv.tv_sec = strtol(shoptarg, &tvptr, 0);
194 if (tvptr == shoptarg)
195 error("timeout value");
196 switch(*tvptr) {
197 case 0:
198 case 's':
199 break;
200 case 'h':
201 tv.tv_sec *= 60;
202 /* FALLTHROUGH */
203 case 'm':
204 tv.tv_sec *= 60;
205 break;
206 default:
207 error("timeout unit");
208 }
209 break;
210 }
211 }
212 if (prompt && isatty(0)) {
213 out2str(prompt);
214 flushall();
215 }
216 if (*(ap = argptr) == NULL)
217 error("arg count");
218 if ((ifs = bltinlookup("IFS", 1)) == NULL)
219 ifs = " \t\n";
220
221 if (tv.tv_sec >= 0) {
222 /*
223 * Wait for something to become available.
224 */
225 FD_ZERO(&ifds);
226 FD_SET(0, &ifds);
227 status = select(1, &ifds, NULL, NULL, &tv);
228 /*
229 * If there's nothing ready, return an error.
230 */
231 if (status <= 0) {
232 while (*ap != NULL)
233 setvar(*ap++, "", 0);
234 sig = pendingsig;
235 return (128 + (sig != 0 ? sig : SIGALRM));
236 }
237 }
238
239 status = 0;
240 startword = 2;
241 backslash = 0;
242 STARTSTACKSTR(p);
243 lastnonifs = lastnonifsws = -1;
244 fdctx_init(STDIN_FILENO, &fdctx);
245 for (;;) {
246 c = 0;
247 nread = fdgetc(&fdctx, &c);
248 if (nread == -1) {
249 if (errno == EINTR) {
250 sig = pendingsig;
251 if (sig == 0)
252 continue;
253 status = 128 + sig;
254 break;
255 }
256 warning("read error: %s", strerror(errno));
257 status = 2;
258 break;
259 } else if (nread != 1) {
260 status = 1;
261 break;
262 }
263 if (c == '\0')
264 continue;
265 CHECKSTRSPACE(1, p);
266 if (backslash) {
267 backslash = 0;
268 if (c != '\n') {
269 startword = 0;
270 lastnonifs = lastnonifsws = p - stackblock();
271 USTPUTC(c, p);
272 }
273 continue;
274 }
275 if (!rflag && c == '\\') {
276 backslash++;
277 continue;
278 }
279 if (c == '\n')
280 break;
281 if (strchr(ifs, c))
282 is_ifs = strchr(" \t\n", c) ? 1 : 2;
283 else
284 is_ifs = 0;
285
286 if (startword != 0) {
287 if (is_ifs == 1) {
288 /* Ignore leading IFS whitespace */
289 if (saveall)
290 USTPUTC(c, p);
291 continue;
292 }
293 if (is_ifs == 2 && startword == 1) {
294 /* Only one non-whitespace IFS per word */
295 startword = 2;
296 if (saveall) {
297 lastnonifsws = p - stackblock();
298 USTPUTC(c, p);
299 }
300 continue;
301 }
302 }
303
304 if (is_ifs == 0) {
305 /* append this character to the current variable */
306 startword = 0;
307 if (saveall)
308 /* Not just a spare terminator */
309 saveall++;
310 lastnonifs = lastnonifsws = p - stackblock();
311 USTPUTC(c, p);
312 continue;
313 }
314
315 /* end of variable... */
316 startword = is_ifs;
317
318 if (ap[1] == NULL) {
319 /* Last variable needs all IFS chars */
320 saveall++;
321 if (is_ifs == 2)
322 lastnonifsws = p - stackblock();
323 USTPUTC(c, p);
324 continue;
325 }
326
327 STACKSTRNUL(p);
328 setvar(*ap, stackblock(), 0);
329 ap++;
330 STARTSTACKSTR(p);
331 lastnonifs = lastnonifsws = -1;
332 }
333 fdctx_destroy(&fdctx);
334 STACKSTRNUL(p);
335
336 /*
337 * Remove trailing IFS chars: always remove whitespace, don't remove
338 * non-whitespace unless it was naked
339 */
340 if (saveall <= 1)
341 lastnonifsws = lastnonifs;
342 stackblock()[lastnonifsws + 1] = '\0';
343 setvar(*ap, stackblock(), 0);
344
345 /* Set any remaining args to "" */
346 while (*++ap != NULL)
347 setvar(*ap, "", 0);
348 return status;
349 }
350
351
352
353 int
umaskcmd(int argc __unused,char ** argv __unused)354 umaskcmd(int argc __unused, char **argv __unused)
355 {
356 char *ap;
357 int mask;
358 int i;
359 int symbolic_mode = 0;
360
361 while ((i = nextopt("S")) != '\0') {
362 symbolic_mode = 1;
363 }
364
365 INTOFF;
366 mask = umask(0);
367 umask(mask);
368 INTON;
369
370 if ((ap = *argptr) == NULL) {
371 if (symbolic_mode) {
372 char u[4], g[4], o[4];
373
374 i = 0;
375 if ((mask & S_IRUSR) == 0)
376 u[i++] = 'r';
377 if ((mask & S_IWUSR) == 0)
378 u[i++] = 'w';
379 if ((mask & S_IXUSR) == 0)
380 u[i++] = 'x';
381 u[i] = '\0';
382
383 i = 0;
384 if ((mask & S_IRGRP) == 0)
385 g[i++] = 'r';
386 if ((mask & S_IWGRP) == 0)
387 g[i++] = 'w';
388 if ((mask & S_IXGRP) == 0)
389 g[i++] = 'x';
390 g[i] = '\0';
391
392 i = 0;
393 if ((mask & S_IROTH) == 0)
394 o[i++] = 'r';
395 if ((mask & S_IWOTH) == 0)
396 o[i++] = 'w';
397 if ((mask & S_IXOTH) == 0)
398 o[i++] = 'x';
399 o[i] = '\0';
400
401 out1fmt("u=%s,g=%s,o=%s\n", u, g, o);
402 } else {
403 out1fmt("%.4o\n", mask);
404 }
405 } else {
406 if (is_digit(*ap)) {
407 mask = 0;
408 do {
409 if (*ap >= '8' || *ap < '0')
410 error("Illegal number: %s", *argptr);
411 mask = (mask << 3) + (*ap - '0');
412 } while (*++ap != '\0');
413 umask(mask);
414 } else {
415 void *set;
416 INTOFF;
417 if ((set = setmode (ap)) == NULL)
418 error("Illegal number: %s", ap);
419
420 mask = getmode (set, ~mask & 0777);
421 umask(~mask & 0777);
422 free(set);
423 INTON;
424 }
425 }
426 return 0;
427 }
428
429 /*
430 * ulimit builtin
431 *
432 * This code, originally by Doug Gwyn, Doug Kingston, Eric Gisin, and
433 * Michael Rendell was ripped from pdksh 5.0.8 and hacked for use with
434 * ash by J.T. Conklin.
435 *
436 * Public domain.
437 */
438
439 struct limits {
440 const char *name;
441 const char *units;
442 int cmd;
443 short factor; /* multiply by to get rlim_{cur,max} values */
444 char option;
445 };
446
447 static const struct limits limits[] = {
448 #ifdef RLIMIT_CPU
449 { "cpu time", "seconds", RLIMIT_CPU, 1, 't' },
450 #endif
451 #ifdef RLIMIT_FSIZE
452 { "file size", "512-blocks", RLIMIT_FSIZE, 512, 'f' },
453 #endif
454 #ifdef RLIMIT_DATA
455 { "data seg size", "kbytes", RLIMIT_DATA, 1024, 'd' },
456 #endif
457 #ifdef RLIMIT_STACK
458 { "stack size", "kbytes", RLIMIT_STACK, 1024, 's' },
459 #endif
460 #ifdef RLIMIT_CORE
461 { "core file size", "512-blocks", RLIMIT_CORE, 512, 'c' },
462 #endif
463 #ifdef RLIMIT_RSS
464 { "max memory size", "kbytes", RLIMIT_RSS, 1024, 'm' },
465 #endif
466 #ifdef RLIMIT_MEMLOCK
467 { "locked memory", "kbytes", RLIMIT_MEMLOCK, 1024, 'l' },
468 #endif
469 #ifdef RLIMIT_NPROC
470 { "max user processes", (char *)0, RLIMIT_NPROC, 1, 'u' },
471 #endif
472 #ifdef RLIMIT_NOFILE
473 { "open files", (char *)0, RLIMIT_NOFILE, 1, 'n' },
474 #endif
475 #ifdef RLIMIT_VMEM
476 { "virtual mem size", "kbytes", RLIMIT_VMEM, 1024, 'v' },
477 #endif
478 #ifdef RLIMIT_SWAP
479 { "swap limit", "kbytes", RLIMIT_SWAP, 1024, 'w' },
480 #endif
481 #ifdef RLIMIT_SBSIZE
482 { "socket buffer size", "bytes", RLIMIT_SBSIZE, 1, 'b' },
483 #endif
484 #ifdef RLIMIT_NPTS
485 { "pseudo-terminals", (char *)0, RLIMIT_NPTS, 1, 'p' },
486 #endif
487 #ifdef RLIMIT_KQUEUES
488 { "kqueues", (char *)0, RLIMIT_KQUEUES, 1, 'k' },
489 #endif
490 #ifdef RLIMIT_UMTXP
491 { "umtx shared locks", (char *)0, RLIMIT_UMTXP, 1, 'o' },
492 #endif
493 #ifdef RLIMIT_PIPEBUF
494 { "pipebuf", (char *)0, RLIMIT_PIPEBUF, 1024, 'y' },
495 #endif
496 { (char *) 0, (char *)0, 0, 0, '\0' }
497 };
498
499 enum limithow { SOFT = 0x1, HARD = 0x2 };
500
501 static void
printlimit(enum limithow how,const struct rlimit * limit,const struct limits * l)502 printlimit(enum limithow how, const struct rlimit *limit,
503 const struct limits *l)
504 {
505 rlim_t val = 0;
506
507 if (how & SOFT)
508 val = limit->rlim_cur;
509 else if (how & HARD)
510 val = limit->rlim_max;
511 if (val == RLIM_INFINITY)
512 out1str("unlimited\n");
513 else
514 {
515 val /= l->factor;
516 out1fmt("%jd\n", (intmax_t)val);
517 }
518 }
519
520 int
ulimitcmd(int argc __unused,char ** argv __unused)521 ulimitcmd(int argc __unused, char **argv __unused)
522 {
523 rlim_t val = 0;
524 enum limithow how = SOFT | HARD;
525 const struct limits *l;
526 int set, all = 0;
527 int optc, what;
528 struct rlimit limit;
529
530 what = 'f';
531 while ((optc = nextopt("HSatfdsmcnuvlbpwkoy")) != '\0')
532 switch (optc) {
533 case 'H':
534 how = HARD;
535 break;
536 case 'S':
537 how = SOFT;
538 break;
539 case 'a':
540 all = 1;
541 break;
542 default:
543 what = optc;
544 }
545
546 for (l = limits; l->name && l->option != what; l++)
547 ;
548 if (!l->name)
549 error("internal error (%c)", what);
550
551 set = *argptr ? 1 : 0;
552 if (set) {
553 char *p = *argptr;
554
555 if (all || argptr[1])
556 error("too many arguments");
557 if (strcmp(p, "unlimited") == 0)
558 val = RLIM_INFINITY;
559 else {
560 char *end;
561 uintmax_t uval;
562
563 if (*p < '0' || *p > '9')
564 error("bad number");
565 errno = 0;
566 uval = strtoumax(p, &end, 10);
567 if (errno != 0 || *end != '\0')
568 error("bad number");
569 if (uval > UINTMAX_MAX / l->factor)
570 error("bad number");
571 uval *= l->factor;
572 val = (rlim_t)uval;
573 if (val < 0 || (uintmax_t)val != uval ||
574 val == RLIM_INFINITY)
575 error("bad number");
576 }
577 }
578 if (all) {
579 for (l = limits; l->name; l++) {
580 char optbuf[40];
581 if (getrlimit(l->cmd, &limit) < 0)
582 error("can't get limit: %s", strerror(errno));
583
584 if (l->units)
585 snprintf(optbuf, sizeof(optbuf),
586 "(%s, -%c) ", l->units, l->option);
587 else
588 snprintf(optbuf, sizeof(optbuf),
589 "(-%c) ", l->option);
590 out1fmt("%-18s %18s ", l->name, optbuf);
591 printlimit(how, &limit, l);
592 }
593 return 0;
594 }
595
596 if (getrlimit(l->cmd, &limit) < 0)
597 error("can't get limit: %s", strerror(errno));
598 if (set) {
599 if (how & SOFT)
600 limit.rlim_cur = val;
601 if (how & HARD)
602 limit.rlim_max = val;
603 if (setrlimit(l->cmd, &limit) < 0)
604 error("bad limit: %s", strerror(errno));
605 } else
606 printlimit(how, &limit, l);
607 return 0;
608 }
609