1 /* $NetBSD: input.c,v 1.47 2016/01/04 03:00:24 christos Exp $ */ 2 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 #include <sys/cdefs.h> 36 #ifndef lint 37 #if 0 38 static char sccsid[] = "@(#)input.c 8.3 (Berkeley) 6/9/95"; 39 #else 40 __RCSID("$NetBSD: input.c,v 1.47 2016/01/04 03:00:24 christos Exp $"); 41 #endif 42 #endif /* not lint */ 43 44 #include <stdio.h> /* defines BUFSIZ */ 45 #include <fcntl.h> 46 #include <errno.h> 47 #include <unistd.h> 48 #include <limits.h> 49 #include <stdlib.h> 50 #include <string.h> 51 52 /* 53 * This file implements the input routines used by the parser. 54 */ 55 56 #include "shell.h" 57 #include "redir.h" 58 #include "syntax.h" 59 #include "input.h" 60 #include "output.h" 61 #include "options.h" 62 #include "memalloc.h" 63 #include "error.h" 64 #include "alias.h" 65 #include "parser.h" 66 #include "myhistedit.h" 67 68 #define EOF_NLEFT -99 /* value of parsenleft when EOF pushed back */ 69 70 MKINIT 71 struct strpush { 72 struct strpush *prev; /* preceding string on stack */ 73 char *prevstring; 74 int prevnleft; 75 int prevlleft; 76 struct alias *ap; /* if push was associated with an alias */ 77 }; 78 79 /* 80 * The parsefile structure pointed to by the global variable parsefile 81 * contains information about the current file being read. 82 */ 83 84 MKINIT 85 struct parsefile { 86 struct parsefile *prev; /* preceding file on stack */ 87 int linno; /* current line */ 88 int fd; /* file descriptor (or -1 if string) */ 89 int nleft; /* number of chars left in this line */ 90 int lleft; /* number of chars left in this buffer */ 91 char *nextc; /* next char in buffer */ 92 char *buf; /* input buffer */ 93 struct strpush *strpush; /* for pushing strings at this level */ 94 struct strpush basestrpush; /* so pushing one is fast */ 95 }; 96 97 98 int plinno = 1; /* input line number */ 99 int parsenleft; /* copy of parsefile->nleft */ 100 MKINIT int parselleft; /* copy of parsefile->lleft */ 101 char *parsenextc; /* copy of parsefile->nextc */ 102 MKINIT struct parsefile basepf; /* top level input file */ 103 MKINIT char basebuf[BUFSIZ]; /* buffer for top level input file */ 104 struct parsefile *parsefile = &basepf; /* current input file */ 105 int init_editline = 0; /* editline library initialized? */ 106 int whichprompt; /* 1 == PS1, 2 == PS2 */ 107 108 STATIC void pushfile(void); 109 static int preadfd(void); 110 111 #ifdef mkinit 112 INCLUDE <stdio.h> 113 INCLUDE "input.h" 114 INCLUDE "error.h" 115 116 INIT { 117 basepf.nextc = basepf.buf = basebuf; 118 } 119 120 RESET { 121 if (exception != EXSHELLPROC) 122 parselleft = parsenleft = 0; /* clear input buffer */ 123 popallfiles(); 124 } 125 126 SHELLPROC { 127 popallfiles(); 128 } 129 #endif 130 131 132 /* 133 * Read a line from the script. 134 */ 135 136 char * 137 pfgets(char *line, int len) 138 { 139 char *p = line; 140 int nleft = len; 141 int c; 142 143 while (--nleft > 0) { 144 c = pgetc_macro(); 145 if (c == PEOF) { 146 if (p == line) 147 return NULL; 148 break; 149 } 150 *p++ = c; 151 if (c == '\n') 152 break; 153 } 154 *p = '\0'; 155 return line; 156 } 157 158 159 160 /* 161 * Read a character from the script, returning PEOF on end of file. 162 * Nul characters in the input are silently discarded. 163 */ 164 165 int 166 pgetc(void) 167 { 168 return pgetc_macro(); 169 } 170 171 172 static int 173 preadfd(void) 174 { 175 int nr; 176 char *buf = parsefile->buf; 177 parsenextc = buf; 178 179 retry: 180 #ifndef SMALL 181 if (parsefile->fd == 0 && el) { 182 static const char *rl_cp; 183 static int el_len; 184 185 if (rl_cp == NULL) 186 rl_cp = el_gets(el, &el_len); 187 if (rl_cp == NULL) 188 nr = el_len == 0 ? 0 : -1; 189 else { 190 nr = el_len; 191 if (nr > BUFSIZ - 8) 192 nr = BUFSIZ - 8; 193 memcpy(buf, rl_cp, nr); 194 if (nr != el_len) { 195 el_len -= nr; 196 rl_cp += nr; 197 } else 198 rl_cp = 0; 199 } 200 201 } else 202 #endif 203 nr = read(parsefile->fd, buf, BUFSIZ - 8); 204 205 206 if (nr <= 0) { 207 if (nr < 0) { 208 if (errno == EINTR) 209 goto retry; 210 if (parsefile->fd == 0 && errno == EWOULDBLOCK) { 211 int flags = fcntl(0, F_GETFL, 0); 212 if (flags >= 0 && flags & O_NONBLOCK) { 213 flags &=~ O_NONBLOCK; 214 if (fcntl(0, F_SETFL, flags) >= 0) { 215 out2str("sh: turning off NDELAY mode\n"); 216 goto retry; 217 } 218 } 219 } 220 } 221 nr = -1; 222 } 223 return nr; 224 } 225 226 /* 227 * Refill the input buffer and return the next input character: 228 * 229 * 1) If a string was pushed back on the input, pop it; 230 * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading 231 * from a string so we can't refill the buffer, return EOF. 232 * 3) If the is more stuff in this buffer, use it else call read to fill it. 233 * 4) Process input up to the next newline, deleting nul characters. 234 */ 235 236 int 237 preadbuffer(void) 238 { 239 char *p, *q; 240 int more; 241 #ifndef SMALL 242 int something; 243 #endif 244 char savec; 245 246 if (parsefile->strpush) { 247 popstring(); 248 if (--parsenleft >= 0) 249 return (*parsenextc++); 250 } 251 if (parsenleft == EOF_NLEFT || parsefile->buf == NULL) 252 return PEOF; 253 flushout(&output); 254 flushout(&errout); 255 256 again: 257 if (parselleft <= 0) { 258 if ((parselleft = preadfd()) == -1) { 259 parselleft = parsenleft = EOF_NLEFT; 260 return PEOF; 261 } 262 } 263 264 q = p = parsenextc; 265 266 /* delete nul characters */ 267 #ifndef SMALL 268 something = 0; 269 #endif 270 for (more = 1; more;) { 271 switch (*p) { 272 case '\0': 273 p++; /* Skip nul */ 274 goto check; 275 276 case '\t': 277 case ' ': 278 break; 279 280 case '\n': 281 parsenleft = q - parsenextc; 282 more = 0; /* Stop processing here */ 283 break; 284 285 default: 286 #ifndef SMALL 287 something = 1; 288 #endif 289 break; 290 } 291 292 *q++ = *p++; 293 check: 294 if (--parselleft <= 0) { 295 parsenleft = q - parsenextc - 1; 296 if (parsenleft < 0) 297 goto again; 298 *q = '\0'; 299 more = 0; 300 } 301 } 302 303 savec = *q; 304 *q = '\0'; 305 306 #ifndef SMALL 307 if (parsefile->fd == 0 && hist && something) { 308 HistEvent he; 309 INTOFF; 310 history(hist, &he, whichprompt == 1? H_ENTER : H_APPEND, 311 parsenextc); 312 INTON; 313 } 314 #endif 315 316 if (vflag) { 317 out2str(parsenextc); 318 flushout(out2); 319 } 320 321 *q = savec; 322 323 return *parsenextc++; 324 } 325 326 /* 327 * Undo the last call to pgetc. Only one character may be pushed back. 328 * PEOF may be pushed back. 329 */ 330 331 void 332 pungetc(void) 333 { 334 parsenleft++; 335 parsenextc--; 336 } 337 338 /* 339 * Push a string back onto the input at this current parsefile level. 340 * We handle aliases this way. 341 */ 342 void 343 pushstring(char *s, int len, void *ap) 344 { 345 struct strpush *sp; 346 347 INTOFF; 348 /*debugprintf("*** calling pushstring: %s, %d\n", s, len);*/ 349 if (parsefile->strpush) { 350 sp = ckmalloc(sizeof (struct strpush)); 351 sp->prev = parsefile->strpush; 352 parsefile->strpush = sp; 353 } else 354 sp = parsefile->strpush = &(parsefile->basestrpush); 355 sp->prevstring = parsenextc; 356 sp->prevnleft = parsenleft; 357 sp->prevlleft = parselleft; 358 sp->ap = (struct alias *)ap; 359 if (ap) 360 ((struct alias *)ap)->flag |= ALIASINUSE; 361 parsenextc = s; 362 parsenleft = len; 363 INTON; 364 } 365 366 void 367 popstring(void) 368 { 369 struct strpush *sp = parsefile->strpush; 370 371 INTOFF; 372 parsenextc = sp->prevstring; 373 parsenleft = sp->prevnleft; 374 parselleft = sp->prevlleft; 375 /*debugprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/ 376 if (sp->ap) 377 sp->ap->flag &= ~ALIASINUSE; 378 parsefile->strpush = sp->prev; 379 if (sp != &(parsefile->basestrpush)) 380 ckfree(sp); 381 INTON; 382 } 383 384 /* 385 * Set the input to take input from a file. If push is set, push the 386 * old input onto the stack first. 387 */ 388 389 void 390 setinputfile(const char *fname, int push) 391 { 392 unsigned char magic[4]; 393 int fd; 394 int fd2; 395 396 INTOFF; 397 if ((fd = open(fname, O_RDONLY)) < 0) 398 error("Can't open %s", fname); 399 400 /* Since the message "Syntax error: "(" unexpected" is not very 401 * helpful, we check if the file starts with the ELF magic to 402 * avoid that message. The first lseek tries to make sure that 403 * we can later rewind the file. 404 */ 405 if (lseek(fd, 0, SEEK_SET) == 0) { 406 if (read(fd, magic, 4) == 4) { 407 if (memcmp(magic, "\177ELF", 4) == 0) 408 error("Cannot execute ELF binary %s", fname); 409 } 410 if (lseek(fd, 0, SEEK_SET) != 0) 411 error("Cannot rewind the file %s", fname); 412 } 413 414 if (fd < 10) { 415 fd2 = copyfd(fd, 10, 0, 0); 416 close(fd); 417 if (fd2 < 0) 418 error("Out of file descriptors"); 419 fd = fd2; 420 } 421 setinputfd(fd, push); 422 INTON; 423 } 424 425 426 /* 427 * Like setinputfile, but takes an open file descriptor. Call this with 428 * interrupts off. 429 */ 430 431 void 432 setinputfd(int fd, int push) 433 { 434 (void) fcntl(fd, F_SETFD, FD_CLOEXEC); 435 if (push) { 436 pushfile(); 437 parsefile->buf = ckmalloc(BUFSIZ); 438 } 439 if (parsefile->fd > 0) 440 close(parsefile->fd); 441 parsefile->fd = fd; 442 if (parsefile->buf == NULL) 443 parsefile->buf = ckmalloc(BUFSIZ); 444 parselleft = parsenleft = 0; 445 plinno = 1; 446 } 447 448 449 /* 450 * Like setinputfile, but takes input from a string. 451 */ 452 453 void 454 setinputstring(char *string, int push) 455 { 456 INTOFF; 457 if (push) 458 pushfile(); 459 parsenextc = string; 460 parselleft = parsenleft = strlen(string); 461 parsefile->buf = NULL; 462 plinno = 1; 463 INTON; 464 } 465 466 467 468 /* 469 * To handle the "." command, a stack of input files is used. Pushfile 470 * adds a new entry to the stack and popfile restores the previous level. 471 */ 472 473 STATIC void 474 pushfile(void) 475 { 476 struct parsefile *pf; 477 478 parsefile->nleft = parsenleft; 479 parsefile->lleft = parselleft; 480 parsefile->nextc = parsenextc; 481 parsefile->linno = plinno; 482 pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile)); 483 pf->prev = parsefile; 484 pf->fd = -1; 485 pf->strpush = NULL; 486 pf->basestrpush.prev = NULL; 487 parsefile = pf; 488 } 489 490 491 void 492 popfile(void) 493 { 494 struct parsefile *pf = parsefile; 495 496 INTOFF; 497 if (pf->fd >= 0) 498 close(pf->fd); 499 if (pf->buf) 500 ckfree(pf->buf); 501 while (pf->strpush) 502 popstring(); 503 parsefile = pf->prev; 504 ckfree(pf); 505 parsenleft = parsefile->nleft; 506 parselleft = parsefile->lleft; 507 parsenextc = parsefile->nextc; 508 plinno = parsefile->linno; 509 INTON; 510 } 511 512 513 /* 514 * Return to top level. 515 */ 516 517 void 518 popallfiles(void) 519 { 520 while (parsefile != &basepf) 521 popfile(); 522 } 523 524 525 526 /* 527 * Close the file(s) that the shell is reading commands from. Called 528 * after a fork is done. 529 * 530 * Takes one arg, vfork, which tells it to not modify its global vars 531 * as it is still running in the parent. 532 * 533 * This code is (probably) unnecessary as the 'close on exec' flag is 534 * set and should be enough. In the vfork case it is definitely wrong 535 * to close the fds as another fork() may be done later to feed data 536 * from a 'here' document into a pipe and we don't want to close the 537 * pipe! 538 */ 539 540 void 541 closescript(int vforked) 542 { 543 if (vforked) 544 return; 545 popallfiles(); 546 if (parsefile->fd > 0) { 547 close(parsefile->fd); 548 parsefile->fd = 0; 549 } 550 } 551