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