input.c revision 1.44.4.1
1/* $NetBSD: input.c,v 1.44.4.1 2012/04/17 00:01:38 yamt 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 38static char sccsid[] = "@(#)input.c 8.3 (Berkeley) 6/9/95"; 39#else 40__RCSID("$NetBSD: input.c,v 1.44.4.1 2012/04/17 00:01:38 yamt 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 70MKINIT 71struct 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 84MKINIT 85struct 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 98int plinno = 1; /* input line number */ 99int parsenleft; /* copy of parsefile->nleft */ 100MKINIT int parselleft; /* copy of parsefile->lleft */ 101char *parsenextc; /* copy of parsefile->nextc */ 102MKINIT struct parsefile basepf; /* top level input file */ 103MKINIT char basebuf[BUFSIZ]; /* buffer for top level input file */ 104struct parsefile *parsefile = &basepf; /* current input file */ 105int init_editline = 0; /* editline library initialized? */ 106int whichprompt; /* 1 == PS1, 2 == PS2 */ 107 108STATIC void pushfile(void); 109static int preadfd(void); 110 111#ifdef mkinit 112INCLUDE <stdio.h> 113INCLUDE "input.h" 114INCLUDE "error.h" 115 116INIT { 117 basepf.nextc = basepf.buf = basebuf; 118} 119 120RESET { 121 if (exception != EXSHELLPROC) 122 parselleft = parsenleft = 0; /* clear input buffer */ 123 popallfiles(); 124} 125 126SHELLPROC { 127 popallfiles(); 128} 129#endif 130 131 132/* 133 * Read a line from the script. 134 */ 135 136char * 137pfgets(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 165int 166pgetc(void) 167{ 168 return pgetc_macro(); 169} 170 171 172static int 173preadfd(void) 174{ 175 int nr; 176 char *buf = parsefile->buf; 177 parsenextc = buf; 178 179retry: 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 236int 237preadbuffer(void) 238{ 239 char *p, *q; 240 int more; 241 int something; 242 char savec; 243 244 if (parsefile->strpush) { 245 popstring(); 246 if (--parsenleft >= 0) 247 return (*parsenextc++); 248 } 249 if (parsenleft == EOF_NLEFT || parsefile->buf == NULL) 250 return PEOF; 251 flushout(&output); 252 flushout(&errout); 253 254again: 255 if (parselleft <= 0) { 256 if ((parselleft = preadfd()) == -1) { 257 parselleft = parsenleft = EOF_NLEFT; 258 return PEOF; 259 } 260 } 261 262 q = p = parsenextc; 263 264 /* delete nul characters */ 265 something = 0; 266 for (more = 1; more;) { 267 switch (*p) { 268 case '\0': 269 p++; /* Skip nul */ 270 goto check; 271 272 case '\t': 273 case ' ': 274 break; 275 276 case '\n': 277 parsenleft = q - parsenextc; 278 more = 0; /* Stop processing here */ 279 break; 280 281 default: 282 something = 1; 283 break; 284 } 285 286 *q++ = *p++; 287check: 288 if (--parselleft <= 0) { 289 parsenleft = q - parsenextc - 1; 290 if (parsenleft < 0) 291 goto again; 292 *q = '\0'; 293 more = 0; 294 } 295 } 296 297 savec = *q; 298 *q = '\0'; 299 300#ifndef SMALL 301 if (parsefile->fd == 0 && hist && something) { 302 HistEvent he; 303 INTOFF; 304 history(hist, &he, whichprompt == 1? H_ENTER : H_APPEND, 305 parsenextc); 306 INTON; 307 } 308#endif 309 310 if (vflag) { 311 out2str(parsenextc); 312 flushout(out2); 313 } 314 315 *q = savec; 316 317 return *parsenextc++; 318} 319 320/* 321 * Undo the last call to pgetc. Only one character may be pushed back. 322 * PEOF may be pushed back. 323 */ 324 325void 326pungetc(void) 327{ 328 parsenleft++; 329 parsenextc--; 330} 331 332/* 333 * Push a string back onto the input at this current parsefile level. 334 * We handle aliases this way. 335 */ 336void 337pushstring(char *s, int len, void *ap) 338{ 339 struct strpush *sp; 340 341 INTOFF; 342/*debugprintf("*** calling pushstring: %s, %d\n", s, len);*/ 343 if (parsefile->strpush) { 344 sp = ckmalloc(sizeof (struct strpush)); 345 sp->prev = parsefile->strpush; 346 parsefile->strpush = sp; 347 } else 348 sp = parsefile->strpush = &(parsefile->basestrpush); 349 sp->prevstring = parsenextc; 350 sp->prevnleft = parsenleft; 351 sp->prevlleft = parselleft; 352 sp->ap = (struct alias *)ap; 353 if (ap) 354 ((struct alias *)ap)->flag |= ALIASINUSE; 355 parsenextc = s; 356 parsenleft = len; 357 INTON; 358} 359 360void 361popstring(void) 362{ 363 struct strpush *sp = parsefile->strpush; 364 365 INTOFF; 366 parsenextc = sp->prevstring; 367 parsenleft = sp->prevnleft; 368 parselleft = sp->prevlleft; 369/*debugprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/ 370 if (sp->ap) 371 sp->ap->flag &= ~ALIASINUSE; 372 parsefile->strpush = sp->prev; 373 if (sp != &(parsefile->basestrpush)) 374 ckfree(sp); 375 INTON; 376} 377 378/* 379 * Set the input to take input from a file. If push is set, push the 380 * old input onto the stack first. 381 */ 382 383void 384setinputfile(const char *fname, int push) 385{ 386 unsigned char magic[4]; 387 int fd; 388 int fd2; 389 390 INTOFF; 391 if ((fd = open(fname, O_RDONLY)) < 0) 392 error("Can't open %s", fname); 393 394 /* Since the message "Syntax error: "(" unexpected" is not very 395 * helpful, we check if the file starts with the ELF magic to 396 * avoid that message. The first lseek tries to make sure that 397 * we can later rewind the file. 398 */ 399 if (lseek(fd, 0, SEEK_SET) == 0) { 400 if (read(fd, magic, 4) == 4) { 401 if (memcmp(magic, "\177ELF", 4) == 0) 402 error("Cannot execute ELF binary %s", fname); 403 } 404 if (lseek(fd, 0, SEEK_SET) != 0) 405 error("Cannot rewind the file %s", fname); 406 } 407 408 if (fd < 10) { 409 fd2 = copyfd(fd, 10, 0); 410 close(fd); 411 if (fd2 < 0) 412 error("Out of file descriptors"); 413 fd = fd2; 414 } 415 setinputfd(fd, push); 416 INTON; 417} 418 419 420/* 421 * Like setinputfile, but takes an open file descriptor. Call this with 422 * interrupts off. 423 */ 424 425void 426setinputfd(int fd, int push) 427{ 428 (void) fcntl(fd, F_SETFD, FD_CLOEXEC); 429 if (push) { 430 pushfile(); 431 parsefile->buf = ckmalloc(BUFSIZ); 432 } 433 if (parsefile->fd > 0) 434 close(parsefile->fd); 435 parsefile->fd = fd; 436 if (parsefile->buf == NULL) 437 parsefile->buf = ckmalloc(BUFSIZ); 438 parselleft = parsenleft = 0; 439 plinno = 1; 440} 441 442 443/* 444 * Like setinputfile, but takes input from a string. 445 */ 446 447void 448setinputstring(char *string, int push) 449{ 450 INTOFF; 451 if (push) 452 pushfile(); 453 parsenextc = string; 454 parselleft = parsenleft = strlen(string); 455 parsefile->buf = NULL; 456 plinno = 1; 457 INTON; 458} 459 460 461 462/* 463 * To handle the "." command, a stack of input files is used. Pushfile 464 * adds a new entry to the stack and popfile restores the previous level. 465 */ 466 467STATIC void 468pushfile(void) 469{ 470 struct parsefile *pf; 471 472 parsefile->nleft = parsenleft; 473 parsefile->lleft = parselleft; 474 parsefile->nextc = parsenextc; 475 parsefile->linno = plinno; 476 pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile)); 477 pf->prev = parsefile; 478 pf->fd = -1; 479 pf->strpush = NULL; 480 pf->basestrpush.prev = NULL; 481 parsefile = pf; 482} 483 484 485void 486popfile(void) 487{ 488 struct parsefile *pf = parsefile; 489 490 INTOFF; 491 if (pf->fd >= 0) 492 close(pf->fd); 493 if (pf->buf) 494 ckfree(pf->buf); 495 while (pf->strpush) 496 popstring(); 497 parsefile = pf->prev; 498 ckfree(pf); 499 parsenleft = parsefile->nleft; 500 parselleft = parsefile->lleft; 501 parsenextc = parsefile->nextc; 502 plinno = parsefile->linno; 503 INTON; 504} 505 506 507/* 508 * Return to top level. 509 */ 510 511void 512popallfiles(void) 513{ 514 while (parsefile != &basepf) 515 popfile(); 516} 517 518 519 520/* 521 * Close the file(s) that the shell is reading commands from. Called 522 * after a fork is done. 523 * 524 * Takes one arg, vfork, which tells it to not modify its global vars 525 * as it is still running in the parent. 526 * 527 * This code is (probably) unnecessary as the 'close on exec' flag is 528 * set and should be enough. In the vfork case it is definitely wrong 529 * to close the fds as another fork() may be done later to feed data 530 * from a 'here' document into a pipe and we don't want to close the 531 * pipe! 532 */ 533 534void 535closescript(int vforked) 536{ 537 if (vforked) 538 return; 539 popallfiles(); 540 if (parsefile->fd > 0) { 541 close(parsefile->fd); 542 parsefile->fd = 0; 543 } 544} 545