The Android Open Source Project | dd7bc33 | 2009-03-03 19:32:55 -0800 | [diff] [blame^] | 1 | /* $NetBSD: input.c,v 1.39 2003/08/07 09:05:32 agc 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 1.39 2003/08/07 09:05:32 agc 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 <stdlib.h> |
| 49 | #include <string.h> |
| 50 | |
| 51 | /* |
| 52 | * This file implements the input routines used by the parser. |
| 53 | */ |
| 54 | |
| 55 | #include "shell.h" |
| 56 | #include "redir.h" |
| 57 | #include "syntax.h" |
| 58 | #include "input.h" |
| 59 | #include "output.h" |
| 60 | #include "options.h" |
| 61 | #include "memalloc.h" |
| 62 | #include "error.h" |
| 63 | #include "alias.h" |
| 64 | #include "parser.h" |
| 65 | #include "myhistedit.h" |
| 66 | |
| 67 | #define EOF_NLEFT -99 /* value of parsenleft when EOF pushed back */ |
| 68 | |
| 69 | MKINIT |
| 70 | struct strpush { |
| 71 | struct strpush *prev; /* preceding string on stack */ |
| 72 | char *prevstring; |
| 73 | int prevnleft; |
| 74 | int prevlleft; |
| 75 | struct alias *ap; /* if push was associated with an alias */ |
| 76 | }; |
| 77 | |
| 78 | /* |
| 79 | * The parsefile structure pointed to by the global variable parsefile |
| 80 | * contains information about the current file being read. |
| 81 | */ |
| 82 | |
| 83 | MKINIT |
| 84 | struct parsefile { |
| 85 | struct parsefile *prev; /* preceding file on stack */ |
| 86 | int linno; /* current line */ |
| 87 | int fd; /* file descriptor (or -1 if string) */ |
| 88 | int nleft; /* number of chars left in this line */ |
| 89 | int lleft; /* number of chars left in this buffer */ |
| 90 | char *nextc; /* next char in buffer */ |
| 91 | char *buf; /* input buffer */ |
| 92 | struct strpush *strpush; /* for pushing strings at this level */ |
| 93 | struct strpush basestrpush; /* so pushing one is fast */ |
| 94 | }; |
| 95 | |
| 96 | |
| 97 | int plinno = 1; /* input line number */ |
| 98 | int parsenleft; /* copy of parsefile->nleft */ |
| 99 | MKINIT int parselleft; /* copy of parsefile->lleft */ |
| 100 | char *parsenextc; /* copy of parsefile->nextc */ |
| 101 | MKINIT struct parsefile basepf; /* top level input file */ |
| 102 | MKINIT char basebuf[BUFSIZ]; /* buffer for top level input file */ |
| 103 | struct parsefile *parsefile = &basepf; /* current input file */ |
| 104 | int init_editline = 0; /* editline library initialized? */ |
| 105 | int whichprompt; /* 1 == PS1, 2 == PS2 */ |
| 106 | |
| 107 | #if WITH_HISTORY |
| 108 | EditLine *el; /* cookie for editline package */ |
| 109 | #endif |
| 110 | |
| 111 | STATIC void pushfile(void); |
| 112 | static int preadfd(void); |
| 113 | |
| 114 | #ifdef mkinit |
| 115 | INCLUDE <stdio.h> |
| 116 | INCLUDE "input.h" |
| 117 | INCLUDE "error.h" |
| 118 | |
| 119 | INIT { |
| 120 | basepf.nextc = basepf.buf = basebuf; |
| 121 | } |
| 122 | |
| 123 | RESET { |
| 124 | if (exception != EXSHELLPROC) |
| 125 | parselleft = parsenleft = 0; /* clear input buffer */ |
| 126 | popallfiles(); |
| 127 | } |
| 128 | |
| 129 | SHELLPROC { |
| 130 | popallfiles(); |
| 131 | } |
| 132 | #endif |
| 133 | |
| 134 | |
| 135 | /* |
| 136 | * Read a line from the script. |
| 137 | */ |
| 138 | |
| 139 | char * |
| 140 | pfgets(char *line, int len) |
| 141 | { |
| 142 | char *p = line; |
| 143 | int nleft = len; |
| 144 | int c; |
| 145 | |
| 146 | while (--nleft > 0) { |
| 147 | c = pgetc_macro(); |
| 148 | if (c == PEOF) { |
| 149 | if (p == line) |
| 150 | return NULL; |
| 151 | break; |
| 152 | } |
| 153 | *p++ = c; |
| 154 | if (c == '\n') |
| 155 | break; |
| 156 | } |
| 157 | *p = '\0'; |
| 158 | return line; |
| 159 | } |
| 160 | |
| 161 | |
| 162 | |
| 163 | /* |
| 164 | * Read a character from the script, returning PEOF on end of file. |
| 165 | * Nul characters in the input are silently discarded. |
| 166 | */ |
| 167 | |
| 168 | int |
| 169 | pgetc(void) |
| 170 | { |
| 171 | return pgetc_macro(); |
| 172 | } |
| 173 | |
| 174 | |
| 175 | static int |
| 176 | preadfd(void) |
| 177 | { |
| 178 | int nr; |
| 179 | char *buf = parsefile->buf; |
| 180 | parsenextc = buf; |
| 181 | |
| 182 | retry: |
| 183 | #ifdef WITH_HISTORY |
| 184 | if (parsefile->fd == 0 && el) { |
| 185 | static const char *rl_cp; |
| 186 | static int el_len; |
| 187 | |
| 188 | if (rl_cp == NULL) |
| 189 | rl_cp = el_gets(el, &el_len); |
| 190 | if (rl_cp == NULL) |
| 191 | nr = 0; |
| 192 | else { |
| 193 | nr = el_len; |
| 194 | if (nr > BUFSIZ - 8) |
| 195 | nr = BUFSIZ - 8; |
| 196 | memcpy(buf, rl_cp, nr); |
| 197 | if (nr != el_len) { |
| 198 | el_len -= nr; |
| 199 | rl_cp += nr; |
| 200 | } else |
| 201 | rl_cp = 0; |
| 202 | } |
| 203 | |
| 204 | } else |
| 205 | #endif |
| 206 | nr = read(parsefile->fd, buf, BUFSIZ - 8); |
| 207 | |
| 208 | |
| 209 | if (nr <= 0) { |
| 210 | if (nr < 0) { |
| 211 | if (errno == EINTR) |
| 212 | goto retry; |
| 213 | if (parsefile->fd == 0 && errno == EWOULDBLOCK) { |
| 214 | int flags = fcntl(0, F_GETFL, 0); |
| 215 | if (flags >= 0 && flags & O_NONBLOCK) { |
| 216 | flags &=~ O_NONBLOCK; |
| 217 | if (fcntl(0, F_SETFL, flags) >= 0) { |
| 218 | out2str("sh: turning off NDELAY mode\n"); |
| 219 | goto retry; |
| 220 | } |
| 221 | } |
| 222 | } |
| 223 | } |
| 224 | nr = -1; |
| 225 | } |
| 226 | return nr; |
| 227 | } |
| 228 | |
| 229 | /* |
| 230 | * Refill the input buffer and return the next input character: |
| 231 | * |
| 232 | * 1) If a string was pushed back on the input, pop it; |
| 233 | * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading |
| 234 | * from a string so we can't refill the buffer, return EOF. |
| 235 | * 3) If the is more stuff in this buffer, use it else call read to fill it. |
| 236 | * 4) Process input up to the next newline, deleting nul characters. |
| 237 | */ |
| 238 | |
| 239 | int |
| 240 | preadbuffer(void) |
| 241 | { |
| 242 | char *p, *q; |
| 243 | int more; |
| 244 | int something; |
| 245 | char savec; |
| 246 | |
| 247 | if (parsefile->strpush) { |
| 248 | popstring(); |
| 249 | if (--parsenleft >= 0) |
| 250 | return (*parsenextc++); |
| 251 | } |
| 252 | if (parsenleft == EOF_NLEFT || parsefile->buf == NULL) |
| 253 | return PEOF; |
| 254 | flushout(&output); |
| 255 | flushout(&errout); |
| 256 | |
| 257 | again: |
| 258 | if (parselleft <= 0) { |
| 259 | if ((parselleft = preadfd()) == -1) { |
| 260 | parselleft = parsenleft = EOF_NLEFT; |
| 261 | return PEOF; |
| 262 | } |
| 263 | } |
| 264 | |
| 265 | q = p = parsenextc; |
| 266 | |
| 267 | /* delete nul characters */ |
| 268 | something = 0; |
| 269 | for (more = 1; more;) { |
| 270 | switch (*p) { |
| 271 | case '\0': |
| 272 | p++; /* Skip nul */ |
| 273 | goto check; |
| 274 | |
| 275 | case '\t': |
| 276 | case ' ': |
| 277 | break; |
| 278 | |
| 279 | case '\n': |
| 280 | parsenleft = q - parsenextc; |
| 281 | more = 0; /* Stop processing here */ |
| 282 | break; |
| 283 | |
| 284 | default: |
| 285 | something = 1; |
| 286 | break; |
| 287 | } |
| 288 | |
| 289 | *q++ = *p++; |
| 290 | check: |
| 291 | if (--parselleft <= 0) { |
| 292 | parsenleft = q - parsenextc - 1; |
| 293 | if (parsenleft < 0) |
| 294 | goto again; |
| 295 | *q = '\0'; |
| 296 | more = 0; |
| 297 | } |
| 298 | } |
| 299 | |
| 300 | savec = *q; |
| 301 | *q = '\0'; |
| 302 | |
| 303 | #ifdef WITH_HISTORY |
| 304 | if (parsefile->fd == 0 && hist && something) { |
| 305 | HistEvent he; |
| 306 | INTOFF; |
| 307 | history(hist, &he, whichprompt == 1? H_ENTER : H_APPEND, |
| 308 | parsenextc); |
| 309 | INTON; |
| 310 | } |
| 311 | #endif |
| 312 | |
| 313 | if (vflag) { |
| 314 | out2str(parsenextc); |
| 315 | flushout(out2); |
| 316 | } |
| 317 | |
| 318 | *q = savec; |
| 319 | |
| 320 | return *parsenextc++; |
| 321 | } |
| 322 | |
| 323 | /* |
| 324 | * Undo the last call to pgetc. Only one character may be pushed back. |
| 325 | * PEOF may be pushed back. |
| 326 | */ |
| 327 | |
| 328 | void |
| 329 | pungetc(void) |
| 330 | { |
| 331 | parsenleft++; |
| 332 | parsenextc--; |
| 333 | } |
| 334 | |
| 335 | /* |
| 336 | * Push a string back onto the input at this current parsefile level. |
| 337 | * We handle aliases this way. |
| 338 | */ |
| 339 | void |
| 340 | pushstring(char *s, int len, void *ap) |
| 341 | { |
| 342 | struct strpush *sp; |
| 343 | |
| 344 | INTOFF; |
| 345 | /*dprintf("*** calling pushstring: %s, %d\n", s, len);*/ |
| 346 | if (parsefile->strpush) { |
| 347 | sp = ckmalloc(sizeof (struct strpush)); |
| 348 | sp->prev = parsefile->strpush; |
| 349 | parsefile->strpush = sp; |
| 350 | } else |
| 351 | sp = parsefile->strpush = &(parsefile->basestrpush); |
| 352 | sp->prevstring = parsenextc; |
| 353 | sp->prevnleft = parsenleft; |
| 354 | sp->prevlleft = parselleft; |
| 355 | sp->ap = (struct alias *)ap; |
| 356 | if (ap) |
| 357 | ((struct alias *)ap)->flag |= ALIASINUSE; |
| 358 | parsenextc = s; |
| 359 | parsenleft = len; |
| 360 | INTON; |
| 361 | } |
| 362 | |
| 363 | void |
| 364 | popstring(void) |
| 365 | { |
| 366 | struct strpush *sp = parsefile->strpush; |
| 367 | |
| 368 | INTOFF; |
| 369 | parsenextc = sp->prevstring; |
| 370 | parsenleft = sp->prevnleft; |
| 371 | parselleft = sp->prevlleft; |
| 372 | /*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/ |
| 373 | if (sp->ap) |
| 374 | sp->ap->flag &= ~ALIASINUSE; |
| 375 | parsefile->strpush = sp->prev; |
| 376 | if (sp != &(parsefile->basestrpush)) |
| 377 | ckfree(sp); |
| 378 | INTON; |
| 379 | } |
| 380 | |
| 381 | /* |
| 382 | * Set the input to take input from a file. If push is set, push the |
| 383 | * old input onto the stack first. |
| 384 | */ |
| 385 | |
| 386 | void |
| 387 | setinputfile(const char *fname, int push) |
| 388 | { |
| 389 | int fd; |
| 390 | int fd2; |
| 391 | |
| 392 | INTOFF; |
| 393 | if ((fd = open(fname, O_RDONLY)) < 0) |
| 394 | error("Can't open %s", fname); |
| 395 | if (fd < 10) { |
| 396 | fd2 = copyfd(fd, 10); |
| 397 | close(fd); |
| 398 | if (fd2 < 0) |
| 399 | error("Out of file descriptors"); |
| 400 | fd = fd2; |
| 401 | } |
| 402 | setinputfd(fd, push); |
| 403 | INTON; |
| 404 | } |
| 405 | |
| 406 | |
| 407 | /* |
| 408 | * Like setinputfile, but takes an open file descriptor. Call this with |
| 409 | * interrupts off. |
| 410 | */ |
| 411 | |
| 412 | void |
| 413 | setinputfd(int fd, int push) |
| 414 | { |
| 415 | (void) fcntl(fd, F_SETFD, FD_CLOEXEC); |
| 416 | if (push) { |
| 417 | pushfile(); |
| 418 | parsefile->buf = ckmalloc(BUFSIZ); |
| 419 | } |
| 420 | if (parsefile->fd > 0) |
| 421 | close(parsefile->fd); |
| 422 | parsefile->fd = fd; |
| 423 | if (parsefile->buf == NULL) |
| 424 | parsefile->buf = ckmalloc(BUFSIZ); |
| 425 | parselleft = parsenleft = 0; |
| 426 | plinno = 1; |
| 427 | } |
| 428 | |
| 429 | |
| 430 | /* |
| 431 | * Like setinputfile, but takes input from a string. |
| 432 | */ |
| 433 | |
| 434 | void |
| 435 | setinputstring(char *string, int push) |
| 436 | { |
| 437 | INTOFF; |
| 438 | if (push) |
| 439 | pushfile(); |
| 440 | parsenextc = string; |
| 441 | parselleft = parsenleft = strlen(string); |
| 442 | parsefile->buf = NULL; |
| 443 | plinno = 1; |
| 444 | INTON; |
| 445 | } |
| 446 | |
| 447 | |
| 448 | |
| 449 | /* |
| 450 | * To handle the "." command, a stack of input files is used. Pushfile |
| 451 | * adds a new entry to the stack and popfile restores the previous level. |
| 452 | */ |
| 453 | |
| 454 | STATIC void |
| 455 | pushfile(void) |
| 456 | { |
| 457 | struct parsefile *pf; |
| 458 | |
| 459 | parsefile->nleft = parsenleft; |
| 460 | parsefile->lleft = parselleft; |
| 461 | parsefile->nextc = parsenextc; |
| 462 | parsefile->linno = plinno; |
| 463 | pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile)); |
| 464 | pf->prev = parsefile; |
| 465 | pf->fd = -1; |
| 466 | pf->strpush = NULL; |
| 467 | pf->basestrpush.prev = NULL; |
| 468 | parsefile = pf; |
| 469 | } |
| 470 | |
| 471 | |
| 472 | void |
| 473 | popfile(void) |
| 474 | { |
| 475 | struct parsefile *pf = parsefile; |
| 476 | |
| 477 | INTOFF; |
| 478 | if (pf->fd >= 0) |
| 479 | close(pf->fd); |
| 480 | if (pf->buf) |
| 481 | ckfree(pf->buf); |
| 482 | while (pf->strpush) |
| 483 | popstring(); |
| 484 | parsefile = pf->prev; |
| 485 | ckfree(pf); |
| 486 | parsenleft = parsefile->nleft; |
| 487 | parselleft = parsefile->lleft; |
| 488 | parsenextc = parsefile->nextc; |
| 489 | plinno = parsefile->linno; |
| 490 | INTON; |
| 491 | } |
| 492 | |
| 493 | |
| 494 | /* |
| 495 | * Return to top level. |
| 496 | */ |
| 497 | |
| 498 | void |
| 499 | popallfiles(void) |
| 500 | { |
| 501 | while (parsefile != &basepf) |
| 502 | popfile(); |
| 503 | } |
| 504 | |
| 505 | |
| 506 | |
| 507 | /* |
| 508 | * Close the file(s) that the shell is reading commands from. Called |
| 509 | * after a fork is done. |
| 510 | * |
| 511 | * Takes one arg, vfork, which tells it to not modify its global vars |
| 512 | * as it is still running in the parent. |
| 513 | * |
| 514 | * This code is (probably) unnecessary as the 'close on exec' flag is |
| 515 | * set and should be enough. In the vfork case it is definitely wrong |
| 516 | * to close the fds as another fork() may be done later to feed data |
| 517 | * from a 'here' document into a pipe and we don't want to close the |
| 518 | * pipe! |
| 519 | */ |
| 520 | |
| 521 | void |
| 522 | closescript(int vforked) |
| 523 | { |
| 524 | if (vforked) |
| 525 | return; |
| 526 | popallfiles(); |
| 527 | if (parsefile->fd > 0) { |
| 528 | close(parsefile->fd); |
| 529 | parsefile->fd = 0; |
| 530 | } |
| 531 | } |