1/* $OpenBSD: csh.c,v 1.50 2023/03/08 04:43:04 guenther Exp $ */ 2/* $NetBSD: csh.c,v 1.14 1995/04/29 23:21:28 mycroft Exp $ */ 3 4/*- 5 * Copyright (c) 1980, 1991, 1993 6 * The Regents of the University of California. All rights reserved. 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. Neither the name of the University nor the names of its contributors 17 * may be used to endorse or promote products derived from this software 18 * without specific prior written permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30 * SUCH DAMAGE. 31 */ 32 33#include <sys/types.h> 34#include <sys/stat.h> 35#include <fcntl.h> 36#include <errno.h> 37#include <pwd.h> 38#include <stdlib.h> 39#include <string.h> 40#include <locale.h> 41#include <unistd.h> 42#include <limits.h> 43#include <vis.h> 44#include <stdarg.h> 45 46#include "csh.h" 47#include "proc.h" 48#include "extern.h" 49#include "pathnames.h" 50 51/* 52 * C Shell 53 * 54 * Bill Joy, UC Berkeley, California, USA 55 * October 1978, May 1980 56 * 57 * Jim Kulp, IIASA, Laxenburg, Austria 58 * April 1980 59 * 60 * Christos Zoulas, Cornell University 61 * June, 1991 62 */ 63 64/* Globals from csh.h */ 65struct timespec time0; 66struct rusage ru0; 67struct Bin B; 68struct Ain lineloc; 69struct whyle *whyles; 70struct varent shvhed, aliases; 71struct wordent *alhistp; 72struct wordent *alhistt; 73struct wordent paraml; 74struct Hist Histlist; 75FILE *cshin, *cshout, *csherr; 76bool chkstop; 77bool didfds; 78bool doneinp; 79bool exiterr; 80bool child; 81bool haderr; 82bool intty; 83bool intact; 84bool justpr; 85bool loginsh; 86bool neednote; 87bool noexec; 88bool pjobs; 89bool setintr; 90bool timflg; 91bool havhash; 92bool needprompt; 93Char *arginp; 94int onelflg; 95Char *ffile; 96Char *doldol; 97int backpid; 98uid_t uid, euid; 99gid_t gid, egid; 100time_t chktim; 101pid_t shpgrp; 102pid_t tpgrp; 103pid_t opgrp; 104int SHIN; 105int SHOUT; 106int SHERR; 107int OLDSTD; 108jmp_buf reslab; 109int exitset; 110Char *gointr; 111sig_t parintr; 112sig_t parterm; 113bool cantell; 114Char *lap; 115Char **alvec; 116int gflag; 117Char *pargs; 118long pnleft; 119Char *pargcp; 120int eventno; 121int lastev; 122Char HIST; 123Char HISTSUB; 124char *bname; 125Char *Vsav; 126Char *Vdp; 127Char *Vexpath; 128char **Vt; 129Char **evalvec; 130Char *evalp; 131Char *word_chars; 132Char *STR_SHELLPATH; 133Char *STR_BSHELL; 134Char *STR_WORD_CHARS; 135Char **STR_environ; 136 137/* Locals */ 138Char *dumphist[] = {STRhistory, STRmh, 0, 0}; 139Char *loadhist[] = {STRsource, STRmh, STRtildothist, 0}; 140 141int nofile = 0; 142bool reenter = 0; 143bool nverbose = 0; 144bool nexececho = 0; 145bool quitit = 0; 146bool fast = 0; 147bool batch = 0; 148bool mflag = 0; 149bool prompt = 1; 150bool enterhist = 0; 151bool tellwhat = 0; 152 153extern char **environ; 154 155static int readf(void *, char *, int); 156static off_t seekf(void *, off_t, int); 157static int writef(void *, const char *, int); 158static int closef(void *); 159static int srccat(Char *, Char *); 160static int srcfile(char *, bool, bool); 161static void phup(int); 162static void srcunit(int, bool, bool); 163static void mailchk(void); 164static Char **defaultpath(void); 165 166int 167main(int argc, char *argv[]) 168{ 169 Char *cp; 170 char *tcp; 171 int f; 172 char **tempv; 173 struct sigaction oact; 174 sigset_t sigset; 175 176 cshin = stdin; 177 cshout = stdout; 178 csherr = stderr; 179 180 settimes(); /* Immed. estab. timing base */ 181 182 /* 183 * Initialize non constant strings 184 */ 185 STR_BSHELL = SAVE(_PATH_BSHELL); 186 STR_SHELLPATH = SAVE(_PATH_CSHELL); 187 STR_environ = blk2short(environ); 188 environ = short2blk(STR_environ); /* So that we can free it */ 189 STR_WORD_CHARS = SAVE(WORD_CHARS); 190 191 HIST = '!'; 192 HISTSUB = '^'; 193 word_chars = STR_WORD_CHARS; 194 195 tempv = argv; 196 if (eq(str2short(tempv[0]), STRaout)) /* A.out's are quittable */ 197 quitit = 1; 198 uid = getuid(); 199 gid = getgid(); 200 euid = geteuid(); 201 egid = getegid(); 202 /* 203 * We are a login shell if: 1. we were invoked as -<something> and we had 204 * no arguments 2. or we were invoked only with the -l flag 205 */ 206 loginsh = (**tempv == '-' && argc == 1) || 207 (argc == 2 && tempv[1][0] == '-' && tempv[1][1] == 'l' && 208 tempv[1][2] == '\0'); 209 210 if (loginsh && **tempv != '-') { 211 /* 212 * Mangle the argv space 213 */ 214 tempv[1][0] = '\0'; 215 tempv[1][1] = '\0'; 216 tempv[1] = NULL; 217 for (tcp = *tempv; *tcp++;) 218 continue; 219 for (tcp--; tcp >= *tempv; tcp--) 220 tcp[1] = tcp[0]; 221 *++tcp = '-'; 222 argc--; 223 } 224 if (loginsh) 225 (void) time(&chktim); 226 227 if (pledge("stdio rpath wpath cpath fattr getpw proc exec tty", 228 NULL) == -1) { 229 perror("pledge"); 230 exit(1); 231 } 232 233 /* 234 * Move the descriptors to safe places. The variable didfds is 0 while we 235 * have only FSH* to work with. When didfds is true, we have 0,1,2 and 236 * prefer to use these. 237 */ 238 initdesc(); 239 /* 240 * XXX: This is to keep programs that use stdio happy. 241 * what we really want is freunopen() .... 242 * Closing cshin cshout and csherr (which are really stdin stdout 243 * and stderr at this point and then reopening them in the same order 244 * gives us again stdin == cshin stdout == cshout and stderr == csherr. 245 * If that was not the case builtins like printf that use stdio 246 * would break. But in any case we could fix that with memcpy and 247 * a bit of pointer manipulation... 248 * Fortunately this is not needed under the current implementation 249 * of stdio. 250 */ 251 (void) fclose(cshin); 252 (void) fclose(cshout); 253 (void) fclose(csherr); 254 if (!(cshin = funopen((void *) &SHIN, readf, writef, seekf, closef))) 255 exit(1); 256 if (!(cshout = funopen((void *) &SHOUT, readf, writef, seekf, closef))) 257 exit(1); 258 if (!(csherr = funopen((void *) &SHERR, readf, writef, seekf, closef))) 259 exit(1); 260 (void) setvbuf(cshin, NULL, _IOLBF, 0); 261 (void) setvbuf(cshout, NULL, _IOLBF, 0); 262 (void) setvbuf(csherr, NULL, _IOLBF, 0); 263 264 /* 265 * Initialize the shell variables. ARGV and PROMPT are initialized later. 266 * STATUS is also munged in several places. CHILD is munged when 267 * forking/waiting 268 */ 269 set(STRstatus, Strsave(STR0)); 270 271 if ((tcp = getenv("HOME")) != NULL && strlen(tcp) < PATH_MAX) 272 cp = SAVE(tcp); 273 else 274 cp = NULL; 275 276 if (cp == NULL) 277 fast = 1; /* No home -> can't read scripts */ 278 else 279 set(STRhome, cp); 280 dinit(cp); /* dinit thinks that HOME == cwd in a login 281 * shell */ 282 /* 283 * Grab other useful things from the environment. Should we grab 284 * everything?? 285 */ 286 if ((tcp = getenv("LOGNAME")) != NULL || 287 (tcp = getenv("USER")) != NULL) 288 set(STRuser, quote(SAVE(tcp))); 289 if ((tcp = getenv("TERM")) != NULL) 290 set(STRterm, quote(SAVE(tcp))); 291 292 /* 293 * Re-initialize path if set in environment 294 */ 295 if ((tcp = getenv("PATH")) == NULL) 296 setq(STRpath, defaultpath(), &shvhed); 297 else 298 importpath(str2short(tcp)); 299 300 set(STRshell, Strsave(STR_SHELLPATH)); 301 302 doldol = putn((int) getpid()); /* For $$ */ 303 304 /* 305 * Record the interrupt states from the parent process. If the parent is 306 * non-interruptible our hand must be forced or we (and our children) won't 307 * be either. Our children inherit termination from our parent. We catch it 308 * only if we are the login shell. 309 */ 310 /* parents interruptibility */ 311 (void) sigaction(SIGINT, NULL, &oact); 312 parintr = oact.sa_handler; 313 (void) sigaction(SIGTERM, NULL, &oact); 314 parterm = oact.sa_handler; 315 316 /* catch these all, login shell or not */ 317 (void) signal(SIGHUP, phup); /* exit processing on HUP */ 318 (void) signal(SIGXCPU, phup); /* ...and on XCPU */ 319 (void) signal(SIGXFSZ, phup); /* ...and on XFSZ */ 320 321 /* 322 * Process the arguments. 323 * 324 * Note that processing of -v/-x is actually delayed till after script 325 * processing. 326 * 327 * We set the first character of our name to be '-' if we are a shell 328 * running interruptible commands. Many programs which examine ps'es 329 * use this to filter such shells out. 330 */ 331 argc--, tempv++; 332 while (argc > 0 && (tcp = tempv[0])[0] == '-' && *++tcp != '\0' && !batch) { 333 do 334 switch (*tcp++) { 335 336 case 0: /* - Interruptible, no prompt */ 337 prompt = 0; 338 setintr = 1; 339 nofile = 1; 340 break; 341 342 case 'b': /* -b Next arg is input file */ 343 batch = 1; 344 break; 345 346 case 'c': /* -c Command input from arg */ 347 if (argc == 1) 348 xexit(0); 349 argc--, tempv++; 350 arginp = SAVE(tempv[0]); 351 prompt = 0; 352 nofile = 1; 353 break; 354 355 case 'e': /* -e Exit on any error */ 356 exiterr = 1; 357 break; 358 359 case 'f': /* -f Fast start */ 360 fast = 1; 361 break; 362 363 case 'i': /* -i Interactive, even if !intty */ 364 intact = 1; 365 nofile = 1; 366 break; 367 368 case 'm': /* -m read .cshrc (from su) */ 369 mflag = 1; 370 break; 371 372 case 'n': /* -n Don't execute */ 373 noexec = 1; 374 break; 375 376 case 'q': /* -q (Undoc'd) ... die on quit */ 377 quitit = 1; 378 break; 379 380 case 's': /* -s Read from std input */ 381 nofile = 1; 382 break; 383 384 case 't': /* -t Read one line from input */ 385 onelflg = 2; 386 prompt = 0; 387 nofile = 1; 388 break; 389 390 case 'v': /* -v Echo hist expanded input */ 391 nverbose = 1; /* ... later */ 392 break; 393 394 case 'x': /* -x Echo just before execution */ 395 nexececho = 1; /* ... later */ 396 break; 397 398 case 'V': /* -V Echo hist expanded input */ 399 setNS(STRverbose); /* NOW! */ 400 break; 401 402 case 'X': /* -X Echo just before execution */ 403 setNS(STRecho); /* NOW! */ 404 break; 405 406 } while (*tcp); 407 tempv++, argc--; 408 } 409 410 if (quitit) /* With all due haste, for debugging */ 411 (void) signal(SIGQUIT, SIG_DFL); 412 413 /* 414 * Unless prevented by -, -c, -i, -s, or -t, if there are remaining 415 * arguments the first of them is the name of a shell file from which to 416 * read commands. 417 */ 418 if (nofile == 0 && argc > 0) { 419 nofile = open(tempv[0], O_RDONLY); 420 if (nofile == -1) { 421 child = 1; /* So this doesn't return */ 422 stderror(ERR_SYSTEM, tempv[0], strerror(errno)); 423 } 424 ffile = SAVE(tempv[0]); 425 /* 426 * Replace FSHIN. Handle /dev/std{in,out,err} specially 427 * since once they are closed we cannot open them again. 428 * In that case we use our own saved descriptors 429 */ 430 if ((SHIN = dmove(nofile, FSHIN)) < 0) 431 switch(nofile) { 432 case 0: 433 SHIN = FSHIN; 434 break; 435 case 1: 436 SHIN = FSHOUT; 437 break; 438 case 2: 439 SHIN = FSHERR; 440 break; 441 default: 442 stderror(ERR_SYSTEM, tempv[0], strerror(errno)); 443 break; 444 } 445 (void) fcntl(SHIN, F_SETFD, FD_CLOEXEC); 446 prompt = 0; 447 /* argc not used any more */ tempv++; 448 } 449 450 intty = isatty(SHIN); 451 intty |= intact; 452 if (intty || (intact && isatty(SHOUT))) { 453 if (!batch && (uid != euid || gid != egid)) { 454 errno = EACCES; 455 child = 1; /* So this doesn't return */ 456 stderror(ERR_SYSTEM, "csh", strerror(errno)); 457 } 458 } 459 /* 460 * Decide whether we should play with signals or not. If we are explicitly 461 * told (via -i, or -) or we are a login shell (arg0 starts with -) or the 462 * input and output are both the ttys("csh", or "csh</dev/ttyx>/dev/ttyx") 463 * Note that in only the login shell is it likely that parent may have set 464 * signals to be ignored 465 */ 466 if (loginsh || intact || (intty && isatty(SHOUT))) 467 setintr = 1; 468 settell(); 469 /* 470 * Save the remaining arguments in argv. 471 */ 472 setq(STRargv, blk2short(tempv), &shvhed); 473 474 /* 475 * Set up the prompt. 476 */ 477 if (prompt) { 478 set(STRprompt, Strsave(uid == 0 ? STRpromptroot : STRpromptuser)); 479 /* that's a meta-questionmark */ 480 set(STRprompt2, Strsave(STRmquestion)); 481 } 482 483 /* 484 * If we are an interactive shell, then start fiddling with the signals; 485 * this is a tricky game. 486 */ 487 shpgrp = getpgrp(); 488 opgrp = tpgrp = -1; 489 if (setintr) { 490 **argv = '-'; 491 if (!quitit) /* Wary! */ 492 (void) signal(SIGQUIT, SIG_IGN); 493 (void) signal(SIGINT, pintr); 494 sigemptyset(&sigset); 495 sigaddset(&sigset, SIGINT); 496 sigprocmask(SIG_BLOCK, &sigset, NULL); 497 (void) signal(SIGTERM, SIG_IGN); 498 if (quitit == 0 && arginp == 0) { 499 (void) signal(SIGTSTP, SIG_IGN); 500 (void) signal(SIGTTIN, SIG_IGN); 501 (void) signal(SIGTTOU, SIG_IGN); 502 /* 503 * Wait till in foreground, in case someone stupidly runs csh & 504 * dont want to try to grab away the tty. 505 */ 506 if (isatty(FSHERR)) 507 f = FSHERR; 508 else if (isatty(FSHOUT)) 509 f = FSHOUT; 510 else if (isatty(OLDSTD)) 511 f = OLDSTD; 512 else 513 f = -1; 514 retry: 515 if ((tpgrp = tcgetpgrp(f)) != -1) { 516 if (tpgrp != shpgrp) { 517 sig_t old = signal(SIGTTIN, SIG_DFL); 518 (void) kill(0, SIGTTIN); 519 (void) signal(SIGTTIN, old); 520 goto retry; 521 } 522 opgrp = shpgrp; 523 shpgrp = getpid(); 524 tpgrp = shpgrp; 525 /* 526 * Setpgid will fail if we are a session leader and 527 * mypid == mypgrp (POSIX 4.3.3) 528 */ 529 if (opgrp != shpgrp) 530 if (setpgid(0, shpgrp) == -1) 531 goto notty; 532 /* 533 * We do that after we set our process group, to make sure 534 * that the process group belongs to a process in the same 535 * session as the tty (our process and our group) (POSIX 7.2.4) 536 */ 537 if (tcsetpgrp(f, shpgrp) == -1) 538 goto notty; 539 (void) fcntl(dcopy(f, FSHTTY), F_SETFD, FD_CLOEXEC); 540 } 541 if (tpgrp == -1) { 542notty: 543 (void) fprintf(csherr, "Warning: no access to tty (%s).\n", 544 strerror(errno)); 545 (void) fprintf(csherr, "Thus no job control in this shell.\n"); 546 } 547 } 548 } 549 if ((setintr == 0) && (parintr == SIG_DFL)) 550 setintr = 1; 551 (void) signal(SIGCHLD, pchild); /* while signals not ready */ 552 553 /* 554 * Set an exit here in case of an interrupt or error reading the shell 555 * start-up scripts. 556 */ 557 reenter = setexit(); /* PWP */ 558 exitset++; 559 haderr = 0; /* In case second time through */ 560 if (!fast && reenter == 0) { 561 /* Will have value(STRhome) here because set fast if don't */ 562 { 563 int osetintr = setintr; 564 sig_t oparintr = parintr; 565 sigset_t osigset; 566 567 sigemptyset(&sigset); 568 sigaddset(&sigset, SIGINT); 569 sigprocmask(SIG_BLOCK, &sigset, &osigset); 570 571 setintr = 0; 572 parintr = SIG_IGN; /* Disable onintr */ 573 (void) srcfile(_PATH_DOTCSHRC, 0, 0); 574 if (!fast && !arginp && !onelflg) 575 dohash(NULL, NULL); 576 if (loginsh) 577 (void) srcfile(_PATH_DOTLOGIN, 0, 0); 578 sigprocmask(SIG_SETMASK, &osigset, NULL); 579 setintr = osetintr; 580 parintr = oparintr; 581 } 582 (void) srccat(value(STRhome), STRsldotcshrc); 583 584 if (!fast && !arginp && !onelflg && !havhash) 585 dohash(NULL, NULL); 586 /* 587 * Source history before .login so that it is available in .login 588 */ 589 if ((cp = value(STRhistfile)) != STRNULL) 590 loadhist[2] = cp; 591 dosource(loadhist, NULL); 592 if (loginsh) 593 (void) srccat(value(STRhome), STRsldotlogin); 594 } 595 596 /* 597 * Now are ready for the -v and -x flags 598 */ 599 if (nverbose) 600 setNS(STRverbose); 601 if (nexececho) 602 setNS(STRecho); 603 604 /* 605 * All the rest of the world is inside this call. The argument to process 606 * indicates whether it should catch "error unwinds". Thus if we are a 607 * interactive shell our call here will never return by being blown past on 608 * an error. 609 */ 610 process(setintr); 611 612 /* 613 * Mop-up. 614 */ 615 if (intty) { 616 if (loginsh) { 617 (void) fprintf(cshout, "logout\n"); 618 (void) close(SHIN); 619 child = 1; 620 goodbye(); 621 } 622 else { 623 (void) fprintf(cshout, "exit\n"); 624 } 625 } 626 rechist(); 627 exitstat(); 628 return (0); 629} 630 631void 632untty(void) 633{ 634 if (tpgrp > 0) { 635 (void) setpgid(0, opgrp); 636 (void) tcsetpgrp(FSHTTY, opgrp); 637 } 638} 639 640void 641importpath(Char *cp) 642{ 643 int i = 0; 644 Char *dp; 645 Char **pv; 646 int c; 647 648 for (dp = cp; *dp; dp++) 649 if (*dp == ':') 650 i++; 651 /* 652 * i+2 where i is the number of colons in the path. There are i+1 653 * directories in the path plus we need room for a zero terminator. 654 */ 655 pv = xcalloc(i + 2, sizeof(*pv)); 656 dp = cp; 657 i = 0; 658 if (*dp) 659 for (;;) { 660 if ((c = *dp) == ':' || c == 0) { 661 *dp = 0; 662 pv[i++] = Strsave(*cp ? cp : STRdot); 663 if (c) { 664 cp = dp + 1; 665 *dp = ':'; 666 } 667 else 668 break; 669 } 670 dp++; 671 } 672 pv[i] = 0; 673 setq(STRpath, pv, &shvhed); 674} 675 676/* 677 * Source to the file which is the catenation of the argument names. 678 */ 679static int 680srccat(Char *cp, Char *dp) 681{ 682 Char *ep = Strspl(cp, dp); 683 char *ptr = short2str(ep); 684 685 free(ep); 686 return srcfile(ptr, mflag ? 0 : 1, 0); 687} 688 689/* 690 * Source to a file putting the file descriptor in a safe place (> 2). 691 */ 692static int 693srcfile(char *f, bool onlyown, bool flag) 694{ 695 int unit; 696 697 if ((unit = open(f, O_RDONLY)) == -1) 698 return 0; 699 unit = dmove(unit, -1); 700 701 (void) fcntl(unit, F_SETFD, FD_CLOEXEC); 702 srcunit(unit, onlyown, flag); 703 return 1; 704} 705 706/* 707 * Source to a unit. If onlyown it must be our file or our group or 708 * we don't chance it. This occurs on ".cshrc"s and the like. 709 */ 710int insource; 711static void 712srcunit(int unit, bool onlyown, bool hflg) 713{ 714 /* We have to push down a lot of state here */ 715 /* All this could go into a structure */ 716 int oSHIN = -1, oldintty = intty, oinsource = insource; 717 struct whyle *oldwhyl = whyles; 718 Char *ogointr = gointr, *oarginp = arginp; 719 Char *oevalp = evalp, **oevalvec = evalvec; 720 int oonelflg = onelflg; 721 bool oenterhist = enterhist; 722 char OHIST = HIST; 723 bool otell = cantell; 724 725 struct Bin saveB; 726 sigset_t sigset, osigset; 727 jmp_buf oldexit; 728 729 /* The (few) real local variables */ 730 int my_reenter; 731 732 if (unit < 0) 733 return; 734 if (didfds) 735 donefds(); 736 if (onlyown) { 737 struct stat stb; 738 739 if (fstat(unit, &stb) == -1) { 740 (void) close(unit); 741 return; 742 } 743 } 744 745 /* 746 * There is a critical section here while we are pushing down the input 747 * stream since we have stuff in different structures. If we weren't 748 * careful an interrupt could corrupt SHIN's Bin structure and kill the 749 * shell. 750 * 751 * We could avoid the critical region by grouping all the stuff in a single 752 * structure and pointing at it to move it all at once. This is less 753 * efficient globally on many variable references however. 754 */ 755 insource = 1; 756 getexit(oldexit); 757 758 if (setintr) { 759 sigemptyset(&sigset); 760 sigaddset(&sigset, SIGINT); 761 sigprocmask(SIG_BLOCK, &sigset, &osigset); 762 } 763 /* Setup the new values of the state stuff saved above */ 764 memcpy(&saveB, &B, sizeof(B)); 765 fbuf = NULL; 766 fseekp = feobp = fblocks = 0; 767 oSHIN = SHIN, SHIN = unit, arginp = 0, onelflg = 0; 768 intty = isatty(SHIN), whyles = 0, gointr = 0; 769 evalvec = 0; 770 evalp = 0; 771 enterhist = hflg; 772 if (enterhist) 773 HIST = '\0'; 774 775 /* 776 * Now if we are allowing commands to be interrupted, we let ourselves be 777 * interrupted. 778 */ 779 if (setintr) 780 sigprocmask(SIG_SETMASK, &osigset, NULL); 781 settell(); 782 783 if ((my_reenter = setexit()) == 0) 784 process(0); /* 0 -> blow away on errors */ 785 786 if (setintr) 787 sigprocmask(SIG_SETMASK, &osigset, NULL); 788 if (oSHIN >= 0) { 789 int i; 790 791 /* We made it to the new state... free up its storage */ 792 /* This code could get run twice but free doesn't care */ 793 for (i = 0; i < fblocks; i++) 794 free(fbuf[i]); 795 free(fbuf); 796 797 /* Reset input arena */ 798 memcpy(&B, &saveB, sizeof(B)); 799 800 (void) close(SHIN), SHIN = oSHIN; 801 arginp = oarginp, onelflg = oonelflg; 802 evalp = oevalp, evalvec = oevalvec; 803 intty = oldintty, whyles = oldwhyl, gointr = ogointr; 804 if (enterhist) 805 HIST = OHIST; 806 enterhist = oenterhist; 807 cantell = otell; 808 } 809 810 resexit(oldexit); 811 /* 812 * If process reset() (effectively an unwind) then we must also unwind. 813 */ 814 if (my_reenter) 815 stderror(ERR_SILENT); 816 insource = oinsource; 817} 818 819void 820rechist(void) 821{ 822 Char buf[BUFSIZ], hbuf[BUFSIZ], *hfile; 823 int fd, ftmp, oldidfds; 824 struct varent *shist; 825 826 if (!fast) { 827 /* 828 * If $savehist is just set, we use the value of $history 829 * else we use the value in $savehist 830 */ 831 if ((shist = adrof(STRsavehist)) != NULL) { 832 if (shist->vec[0][0] != '\0') 833 (void) Strlcpy(hbuf, shist->vec[0], sizeof hbuf/sizeof(Char)); 834 else if ((shist = adrof(STRhistory)) && shist->vec[0][0] != '\0') 835 (void) Strlcpy(hbuf, shist->vec[0], sizeof hbuf/sizeof(Char)); 836 else 837 return; 838 } 839 else 840 return; 841 842 if ((hfile = value(STRhistfile)) == STRNULL) { 843 Strlcpy(buf, value(STRhome), sizeof buf/sizeof(Char)); 844 hfile = buf; 845 (void) Strlcat(buf, STRsldthist, sizeof buf/sizeof(Char)); 846 } 847 848 if ((fd = open(short2str(hfile), O_WRONLY | O_CREAT | O_TRUNC, 849 0600)) == -1) 850 return; 851 852 oldidfds = didfds; 853 didfds = 0; 854 ftmp = SHOUT; 855 SHOUT = fd; 856 dumphist[2] = hbuf; 857 dohist(dumphist, NULL); 858 SHOUT = ftmp; 859 (void) close(fd); 860 didfds = oldidfds; 861 } 862} 863 864void 865goodbye(void) 866{ 867 rechist(); 868 869 if (loginsh) { 870 (void) signal(SIGQUIT, SIG_IGN); 871 (void) signal(SIGINT, SIG_IGN); 872 (void) signal(SIGTERM, SIG_IGN); 873 setintr = 0; /* No interrupts after "logout" */ 874 if (!(adrof(STRlogout))) 875 set(STRlogout, STRnormal); 876 (void) srcfile(_PATH_DOTLOGOUT, 0, 0); 877 if (adrof(STRhome)) 878 (void) srccat(value(STRhome), STRsldtlogout); 879 } 880 exitstat(); 881} 882 883void 884exitstat(void) 885{ 886 Char *s; 887 /* 888 * Note that if STATUS is corrupted (i.e. getn bombs) then error will exit 889 * directly because we poke child here. Otherwise we might continue 890 * unwarrantedly (sic). 891 */ 892 child = 1; 893 s = value(STRstatus); 894 xexit(s ? getn(s) : 0); 895} 896 897/* 898 * in the event of a HUP we want to save the history 899 */ 900static void 901phup(int sig) 902{ 903 /* XXX sigh, everything after this is a signal race */ 904 905 rechist(); 906 907 /* 908 * We kill the last foreground process group. It then becomes 909 * responsible to propagate the SIGHUP to its progeny. 910 */ 911 { 912 struct process *pp, *np; 913 914 for (pp = proclist.p_next; pp; pp = pp->p_next) { 915 np = pp; 916 /* 917 * Find if this job is in the foreground. It could be that 918 * the process leader has exited and the foreground flag 919 * is cleared for it. 920 */ 921 do 922 /* 923 * If a process is in the foreground; we try to kill 924 * its process group. If we succeed, then the 925 * whole job is gone. Otherwise we keep going... 926 * But avoid sending HUP to the shell again. 927 */ 928 if ((np->p_flags & PFOREGND) != 0 && np->p_jobid != shpgrp && 929 kill(-np->p_jobid, SIGHUP) != -1) { 930 /* In case the job was suspended... */ 931 (void) kill(-np->p_jobid, SIGCONT); 932 break; 933 } 934 while ((np = np->p_friends) != pp); 935 } 936 } 937 xexit(sig); 938} 939 940Char *jobargv[2] = {STRjobs, 0}; 941 942/* 943 * Catch an interrupt, e.g. during lexical input. 944 * If we are an interactive shell, we reset the interrupt catch 945 * immediately. In any case we drain the shell output, 946 * and finally go through the normal error mechanism, which 947 * gets a chance to make the shell go away. 948 */ 949void 950pintr(int notused) 951{ 952 int save_errno = errno; 953 954 pintr1(1); 955 errno = save_errno; 956} 957 958void 959pintr1(bool wantnl) 960{ 961 sigset_t sigset, osigset; 962 963 sigemptyset(&sigset); 964 sigprocmask(SIG_BLOCK, &sigset, &osigset); 965 if (setintr) { 966 sigset = osigset; 967 sigdelset(&sigset, SIGINT); 968 sigprocmask(SIG_SETMASK, &sigset, NULL); 969 if (pjobs) { 970 pjobs = 0; 971 (void) fprintf(cshout, "\n"); 972 dojobs(jobargv, NULL); 973 stderror(ERR_NAME | ERR_INTR); 974 } 975 } 976 sigdelset(&osigset, SIGCHLD); 977 sigprocmask(SIG_SETMASK, &osigset, NULL); 978 (void) fpurge(cshout); 979 (void) endpwent(); 980 981 /* 982 * If we have an active "onintr" then we search for the label. Note that if 983 * one does "onintr -" then we shan't be interruptible so we needn't worry 984 * about that here. 985 */ 986 if (gointr) { 987 gotolab(gointr); 988 timflg = 0; 989 blkfree(pargv); 990 pargv = NULL; 991 blkfree(gargv); 992 gargv = NULL; 993 reset(); 994 } 995 else if (intty && wantnl) { 996 (void) fputc('\r', cshout); 997 (void) fputc('\n', cshout); 998 } 999 stderror(ERR_SILENT); 1000} 1001 1002/* 1003 * Process is the main driving routine for the shell. 1004 * It runs all command processing, except for those within { ... } 1005 * in expressions (which is run by a routine evalav in sh.exp.c which 1006 * is a stripped down process), and `...` evaluation which is run 1007 * also by a subset of this code in sh.glob.c in the routine backeval. 1008 * 1009 * The code here is a little strange because part of it is interruptible 1010 * and hence freeing of structures appears to occur when none is necessary 1011 * if this is ignored. 1012 * 1013 * Note that if catch is not set then we will unwind on any error. 1014 * If an end-of-file occurs, we return. 1015 */ 1016static struct command *savet = NULL; 1017void 1018process(bool catch) 1019{ 1020 jmp_buf osetexit; 1021 struct command *t = savet; 1022 sigset_t sigset; 1023 1024 savet = NULL; 1025 getexit(osetexit); 1026 for (;;) { 1027 pendjob(); 1028 paraml.next = paraml.prev = ¶ml; 1029 paraml.word = STRNULL; 1030 (void) setexit(); 1031 justpr = enterhist; /* execute if not entering history */ 1032 1033 /* 1034 * Interruptible during interactive reads 1035 */ 1036 if (setintr) { 1037 sigemptyset(&sigset); 1038 sigaddset(&sigset, SIGINT); 1039 sigprocmask(SIG_UNBLOCK, &sigset, NULL); 1040 } 1041 1042 /* 1043 * For the sake of reset() 1044 */ 1045 freelex(¶ml); 1046 if (savet) 1047 freesyn(savet), savet = NULL; 1048 1049 if (haderr) { 1050 if (!catch) { 1051 /* unwind */ 1052 doneinp = 0; 1053 resexit(osetexit); 1054 savet = t; 1055 reset(); 1056 } 1057 haderr = 0; 1058 /* 1059 * Every error is eventually caught here or the shell dies. It is 1060 * at this point that we clean up any left-over open files, by 1061 * closing all but a fixed number of pre-defined files. Thus 1062 * routines don't have to worry about leaving files open due to 1063 * deeper errors... they will get closed here. 1064 */ 1065 closem(); 1066 continue; 1067 } 1068 if (doneinp) { 1069 doneinp = 0; 1070 break; 1071 } 1072 if (chkstop) 1073 chkstop--; 1074 if (neednote) 1075 pnote(); 1076 if (intty && prompt && evalvec == 0) { 1077 mailchk(); 1078 /* 1079 * If we are at the end of the input buffer then we are going to 1080 * read fresh stuff. Otherwise, we are rereading input and don't 1081 * need or want to prompt. 1082 */ 1083 needprompt = aret == F_SEEK && fseekp == feobp; 1084 if (!filec && needprompt) 1085 printprompt(); 1086 (void) fflush(cshout); 1087 } 1088 free(seterr); 1089 seterr = NULL; 1090 1091 /* 1092 * Echo not only on VERBOSE, but also with history expansion. If there 1093 * is a lexical error then we forego history echo. 1094 */ 1095 if ((lex(¶ml) && !seterr && intty) || adrof(STRverbose)) { 1096 prlex(csherr, ¶ml); 1097 } 1098 1099 /* 1100 * The parser may lose space if interrupted. 1101 */ 1102 if (setintr) 1103 sigprocmask(SIG_BLOCK, &sigset, NULL); 1104 1105 /* 1106 * Save input text on the history list if reading in old history, or it 1107 * is from the terminal at the top level and not in a loop. 1108 * 1109 * PWP: entry of items in the history list while in a while loop is done 1110 * elsewhere... 1111 */ 1112 if (enterhist || (catch && intty && !whyles)) 1113 savehist(¶ml); 1114 1115 /* 1116 * Print lexical error messages, except when sourcing history lists. 1117 */ 1118 if (!enterhist && seterr) 1119 stderror(ERR_OLD); 1120 1121 /* 1122 * If had a history command :p modifier then this is as far as we 1123 * should go 1124 */ 1125 if (justpr) 1126 reset(); 1127 1128 alias(¶ml); 1129 1130 /* 1131 * Parse the words of the input into a parse tree. 1132 */ 1133 savet = syntax(paraml.next, ¶ml, 0); 1134 if (seterr) 1135 stderror(ERR_OLD); 1136 1137 execute(savet, (tpgrp > 0 ? tpgrp : -1), NULL, NULL); 1138 1139 /* 1140 * Made it! 1141 */ 1142 freelex(¶ml); 1143 freesyn((struct command *) savet), savet = NULL; 1144 } 1145 resexit(osetexit); 1146 savet = t; 1147} 1148 1149void 1150dosource(Char **v, struct command *t) 1151{ 1152 Char *f; 1153 bool hflg = 0; 1154 Char buf[BUFSIZ]; 1155 char sbuf[BUFSIZ]; 1156 1157 v++; 1158 if (*v && eq(*v, STRmh)) { 1159 if (*++v == NULL) 1160 stderror(ERR_NAME | ERR_HFLAG); 1161 hflg++; 1162 } 1163 (void) Strlcpy(buf, *v, sizeof buf/sizeof(Char)); 1164 f = globone(buf, G_ERROR); 1165 (void) strlcpy(sbuf, short2str(f), sizeof sbuf); 1166 free(f); 1167 if (!srcfile(sbuf, 0, hflg) && !hflg) 1168 stderror(ERR_SYSTEM, sbuf, strerror(errno)); 1169} 1170 1171/* 1172 * Check for mail. 1173 * If we are a login shell, then we don't want to tell 1174 * about any mail file unless its been modified 1175 * after the time we started. 1176 * This prevents us from telling the user things he already 1177 * knows, since the login program insists on saying 1178 * "You have mail." 1179 */ 1180static void 1181mailchk(void) 1182{ 1183 struct varent *v; 1184 Char **vp; 1185 time_t t; 1186 int intvl, cnt; 1187 struct stat stb; 1188 bool new; 1189 1190 v = adrof(STRmail); 1191 if (v == 0) 1192 return; 1193 (void) time(&t); 1194 vp = v->vec; 1195 cnt = blklen(vp); 1196 intvl = (cnt && number(*vp)) ? (--cnt, getn(*vp++)) : MAILINTVL; 1197 if (intvl < 1) 1198 intvl = 1; 1199 if (chktim + intvl > t) 1200 return; 1201 for (; *vp; vp++) { 1202 if (stat(short2str(*vp), &stb) == -1) 1203 continue; 1204 new = stb.st_mtime > time0.tv_sec; 1205 if (stb.st_size == 0 || stb.st_atime > stb.st_mtime || 1206 (stb.st_atime < chktim && stb.st_mtime < chktim) || 1207 (loginsh && !new)) 1208 continue; 1209 if (cnt == 1) 1210 (void) fprintf(cshout, "You have %smail.\n", new ? "new " : ""); 1211 else 1212 (void) fprintf(cshout, "%s in %s.\n", new ? "New mail" : "Mail", 1213 vis_str(*vp)); 1214 } 1215 chktim = t; 1216} 1217 1218/* 1219 * Extract a home directory from the password file 1220 * The argument points to a buffer where the name of the 1221 * user whose home directory is sought is currently. 1222 * We write the home directory of the user back there. 1223 */ 1224int 1225gethdir(Char *home, int len) 1226{ 1227 Char *h; 1228 struct passwd *pw; 1229 1230 /* 1231 * Is it us? 1232 */ 1233 if (*home == '\0') { 1234 if ((h = value(STRhome)) != NULL) { 1235 if (Strlcpy(home, h, len) >= len) 1236 return 1; 1237 return 0; 1238 } 1239 else 1240 return 1; 1241 } 1242 1243 if ((pw = getpwnam(short2str(home))) != NULL) { 1244 if (Strlcpy(home, str2short(pw->pw_dir), len) >= len) 1245 return 1; 1246 return 0; 1247 } 1248 else 1249 return 1; 1250} 1251 1252/* 1253 * When didfds is set, we do I/O from 0, 1, 2 otherwise from 15, 16, 17 1254 * We also check if the shell has already changed the descriptor to point to 1255 * 0, 1, 2 when didfds is set. 1256 */ 1257#define DESC(a) (*((int *) (a)) - (didfds && *((int *) a) >= FSHIN ? FSHIN : 0)) 1258 1259static int 1260readf(void *oreo, char *buf, int siz) 1261{ 1262 return read(DESC(oreo), buf, siz); 1263} 1264 1265 1266static int 1267writef(void *oreo, const char *buf, int siz) 1268{ 1269 return write(DESC(oreo), buf, siz); 1270} 1271 1272static off_t 1273seekf(void *oreo, off_t off, int whence) 1274{ 1275 return lseek(DESC(oreo), off, whence); 1276} 1277 1278 1279static int 1280closef(void *oreo) 1281{ 1282 return close(DESC(oreo)); 1283} 1284 1285 1286/* 1287 * Print the visible version of a string. 1288 */ 1289int 1290vis_fputc(int ch, FILE *fp) 1291{ 1292 char uenc[5]; /* 4 + NUL */ 1293 1294 if (ch & QUOTE) 1295 return fputc(ch & TRIM, fp); 1296 (void) vis(uenc, ch & TRIM, VIS_NOSLASH, 0); 1297 return fputs(uenc, fp); 1298} 1299 1300/* 1301 * Move the initial descriptors to their eventual 1302 * resting places, closing all other units. 1303 */ 1304void 1305initdesc(void) 1306{ 1307 1308 didfds = 0; /* 0, 1, 2 aren't set up */ 1309 (void) fcntl(SHIN = dcopy(0, FSHIN), F_SETFD, FD_CLOEXEC); 1310 (void) fcntl(SHOUT = dcopy(1, FSHOUT), F_SETFD, FD_CLOEXEC); 1311 (void) fcntl(SHERR = dcopy(2, FSHERR), F_SETFD, FD_CLOEXEC); 1312 (void) fcntl(OLDSTD = dcopy(SHIN, FOLDSTD), F_SETFD, FD_CLOEXEC); 1313 closem(); 1314} 1315 1316 1317void 1318xexit(int i) 1319{ 1320 untty(); 1321 _exit(i); 1322} 1323 1324static Char ** 1325defaultpath(void) 1326{ 1327 char *ptr; 1328 Char **blk, **blkp; 1329 struct stat stb; 1330 1331 blkp = blk = xreallocarray(NULL, 10, sizeof(Char *)); 1332 1333#define DIRAPPEND(a) \ 1334 if (stat(ptr = a, &stb) == 0 && S_ISDIR(stb.st_mode)) \ 1335 *blkp++ = SAVE(ptr) 1336 1337 DIRAPPEND(_PATH_BIN); 1338 DIRAPPEND(_PATH_USRBIN); 1339 1340#undef DIRAPPEND 1341 1342 *blkp = NULL; 1343 return (blk); 1344} 1345 1346void 1347printprompt(void) 1348{ 1349 Char *cp; 1350 1351 if (!whyles) { 1352 for (cp = value(STRprompt); *cp; cp++) 1353 if (*cp == HIST) 1354 (void) fprintf(cshout, "%d", eventno + 1); 1355 else if (*cp == '%' && *(cp + 1) == 'm') { 1356 char hostname[HOST_NAME_MAX + 1]; 1357 char *p; 1358 1359 gethostname(hostname, sizeof hostname); 1360 if ((p = strchr(hostname, '.')) != NULL) 1361 *p = '\0'; 1362 fprintf(cshout, "%s", hostname); 1363 cp++; 1364 } else { 1365 if (*cp == '\\' && cp[1] == HIST) 1366 cp++; 1367 (void) vis_fputc(*cp | QUOTE, cshout); 1368 } 1369 } 1370 else 1371 /* 1372 * Prompt for forward reading loop body content. 1373 */ 1374 (void) fprintf(cshout, "? "); 1375 (void) fflush(cshout); 1376} 1377