1 /*- 2 * Copyright (c) 1991, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software contributed to Berkeley by 6 * Kenneth Almquist. 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 * 4. 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 #ifndef lint 34 #if 0 35 static char sccsid[] = "@(#)input.c 8.3 (Berkeley) 6/9/95"; 36 #endif 37 #endif /* not lint */ 38 #include <sys/cdefs.h> 39 __FBSDID("$FreeBSD$"); 40 41 #include <stdio.h> /* defines BUFSIZ */ 42 #include <fcntl.h> 43 #include <errno.h> 44 #include <unistd.h> 45 #include <stdlib.h> 46 #include <string.h> 47 48 /* 49 * This file implements the input routines used by the parser. 50 */ 51 52 #include "shell.h" 53 #include "redir.h" 54 #include "syntax.h" 55 #include "input.h" 56 #include "output.h" 57 #include "options.h" 58 #include "memalloc.h" 59 #include "error.h" 60 #include "alias.h" 61 #include "parser.h" 62 #include "myhistedit.h" 63 #include "trap.h" 64 65 #define EOF_NLEFT -99 /* value of parsenleft when EOF pushed back */ 66 67 MKINIT 68 struct strpush { 69 struct strpush *prev; /* preceding string on stack */ 70 char *prevstring; 71 int prevnleft; 72 int prevlleft; 73 struct alias *ap; /* if push was associated with an alias */ 74 }; 75 76 /* 77 * The parsefile structure pointed to by the global variable parsefile 78 * contains information about the current file being read. 79 */ 80 81 MKINIT 82 struct parsefile { 83 struct parsefile *prev; /* preceding file on stack */ 84 int linno; /* current line */ 85 int fd; /* file descriptor (or -1 if string) */ 86 int nleft; /* number of chars left in this line */ 87 int lleft; /* number of lines left in this buffer */ 88 char *nextc; /* next char in buffer */ 89 char *buf; /* input buffer */ 90 struct strpush *strpush; /* for pushing strings at this level */ 91 struct strpush basestrpush; /* so pushing one is fast */ 92 }; 93 94 95 int plinno = 1; /* input line number */ 96 int parsenleft; /* copy of parsefile->nleft */ 97 MKINIT int parselleft; /* copy of parsefile->lleft */ 98 char *parsenextc; /* copy of parsefile->nextc */ 99 MKINIT struct parsefile basepf; /* top level input file */ 100 char basebuf[BUFSIZ + 1]; /* buffer for top level input file */ 101 static struct parsefile *parsefile = &basepf; /* current input file */ 102 int init_editline = 0; /* editline library initialized? */ 103 int whichprompt; /* 1 == PS1, 2 == PS2 */ 104 105 EditLine *el; /* cookie for editline package */ 106 107 static void pushfile(void); 108 static int preadfd(void); 109 static void popstring(void); 110 111 #ifdef mkinit 112 INCLUDE "input.h" 113 INCLUDE "error.h" 114 115 MKINIT char basebuf[]; 116 117 INIT { 118 basepf.nextc = basepf.buf = basebuf; 119 } 120 121 RESET { 122 popallfiles(); 123 parselleft = parsenleft = 0; /* clear input buffer */ 124 } 125 #endif 126 127 128 /* 129 * Read a line from the script. 130 */ 131 132 char * 133 pfgets(char *line, int len) 134 { 135 char *p = line; 136 int nleft = len; 137 int c; 138 139 while (--nleft > 0) { 140 c = pgetc_macro(); 141 if (c == PEOF) { 142 if (p == line) 143 return NULL; 144 break; 145 } 146 *p++ = c; 147 if (c == '\n') 148 break; 149 } 150 *p = '\0'; 151 return line; 152 } 153 154 155 156 /* 157 * Read a character from the script, returning PEOF on end of file. 158 * Nul characters in the input are silently discarded. 159 */ 160 161 int 162 pgetc(void) 163 { 164 return pgetc_macro(); 165 } 166 167 168 static int 169 preadfd(void) 170 { 171 int nr; 172 parsenextc = parsefile->buf; 173 174 #ifndef NO_HISTORY 175 if (el != NULL && gotwinch) { 176 gotwinch = 0; 177 el_resize(el); 178 } 179 #endif 180 retry: 181 #ifndef NO_HISTORY 182 if (parsefile->fd == 0 && el) { 183 static const char *rl_cp; 184 static int el_len; 185 186 if (rl_cp == NULL) 187 rl_cp = el_gets(el, &el_len); 188 if (rl_cp == NULL) 189 nr = 0; 190 else { 191 nr = el_len; 192 if (nr > BUFSIZ) 193 nr = BUFSIZ; 194 memcpy(parsenextc, rl_cp, nr); 195 if (nr != el_len) { 196 el_len -= nr; 197 rl_cp += nr; 198 } else 199 rl_cp = NULL; 200 } 201 } else 202 #endif 203 nr = read(parsefile->fd, parsenextc, BUFSIZ); 204 205 if (nr <= 0) { 206 if (nr < 0) { 207 if (errno == EINTR) 208 goto retry; 209 if (parsefile->fd == 0 && errno == EWOULDBLOCK) { 210 int flags = fcntl(0, F_GETFL, 0); 211 if (flags >= 0 && flags & O_NONBLOCK) { 212 flags &=~ O_NONBLOCK; 213 if (fcntl(0, F_SETFL, flags) >= 0) { 214 out2fmt_flush("sh: turning off NDELAY mode\n"); 215 goto retry; 216 } 217 } 218 } 219 } 220 nr = -1; 221 } 222 return nr; 223 } 224 225 /* 226 * Refill the input buffer and return the next input character: 227 * 228 * 1) If a string was pushed back on the input, pop it; 229 * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading 230 * from a string so we can't refill the buffer, return EOF. 231 * 3) If there is more in this buffer, use it else call read to fill it. 232 * 4) Process input up to the next newline, deleting nul characters. 233 */ 234 235 int 236 preadbuffer(void) 237 { 238 char *p, *q; 239 int more; 240 int something; 241 char savec; 242 243 if (parsefile->strpush) { 244 popstring(); 245 if (--parsenleft >= 0) 246 return (*parsenextc++); 247 } 248 if (parsenleft == EOF_NLEFT || parsefile->buf == NULL) 249 return PEOF; 250 flushout(&output); 251 flushout(&errout); 252 253 again: 254 if (parselleft <= 0) { 255 if ((parselleft = preadfd()) == -1) { 256 parselleft = parsenleft = EOF_NLEFT; 257 return PEOF; 258 } 259 } 260 261 q = p = parsenextc; 262 263 /* delete nul characters */ 264 something = 0; 265 for (more = 1; more;) { 266 switch (*p) { 267 case '\0': 268 p++; /* Skip nul */ 269 goto check; 270 271 case '\t': 272 case ' ': 273 break; 274 275 case '\n': 276 parsenleft = q - parsenextc; 277 more = 0; /* Stop processing here */ 278 break; 279 280 default: 281 something = 1; 282 break; 283 } 284 285 *q++ = *p++; 286 check: 287 if (--parselleft <= 0) { 288 parsenleft = q - parsenextc - 1; 289 if (parsenleft < 0) 290 goto again; 291 *q = '\0'; 292 more = 0; 293 } 294 } 295 296 savec = *q; 297 *q = '\0'; 298 299 #ifndef NO_HISTORY 300 if (parsefile->fd == 0 && hist && something) { 301 HistEvent he; 302 INTOFF; 303 history(hist, &he, whichprompt == 1 ? H_ENTER : H_ADD, 304 parsenextc); 305 INTON; 306 } 307 #endif 308 309 if (vflag) { 310 out2str(parsenextc); 311 flushout(out2); 312 } 313 314 *q = savec; 315 316 return *parsenextc++; 317 } 318 319 /* 320 * Returns if we are certain we are at EOF. Does not cause any more input 321 * to be read from the outside world. 322 */ 323 324 int 325 preadateof(void) 326 { 327 if (parsenleft > 0) 328 return 0; 329 if (parsefile->strpush) 330 return 0; 331 if (parsenleft == EOF_NLEFT || parsefile->buf == NULL) 332 return 1; 333 return 0; 334 } 335 336 /* 337 * Undo the last call to pgetc. Only one character may be pushed back. 338 * PEOF may be pushed back. 339 */ 340 341 void 342 pungetc(void) 343 { 344 parsenleft++; 345 parsenextc--; 346 } 347 348 /* 349 * Push a string back onto the input at this current parsefile level. 350 * We handle aliases this way. 351 */ 352 void 353 pushstring(char *s, int len, void *ap) 354 { 355 struct strpush *sp; 356 357 INTOFF; 358 /*out2fmt_flush("*** calling pushstring: %s, %d\n", s, len);*/ 359 if (parsefile->strpush) { 360 sp = ckmalloc(sizeof (struct strpush)); 361 sp->prev = parsefile->strpush; 362 parsefile->strpush = sp; 363 } else 364 sp = parsefile->strpush = &(parsefile->basestrpush); 365 sp->prevstring = parsenextc; 366 sp->prevnleft = parsenleft; 367 sp->prevlleft = parselleft; 368 sp->ap = (struct alias *)ap; 369 if (ap) 370 ((struct alias *)ap)->flag |= ALIASINUSE; 371 parsenextc = s; 372 parsenleft = len; 373 INTON; 374 } 375 376 static void 377 popstring(void) 378 { 379 struct strpush *sp = parsefile->strpush; 380 381 INTOFF; 382 parsenextc = sp->prevstring; 383 parsenleft = sp->prevnleft; 384 parselleft = sp->prevlleft; 385 /*out2fmt_flush("*** calling popstring: restoring to '%s'\n", parsenextc);*/ 386 if (sp->ap) 387 sp->ap->flag &= ~ALIASINUSE; 388 parsefile->strpush = sp->prev; 389 if (sp != &(parsefile->basestrpush)) 390 ckfree(sp); 391 INTON; 392 } 393 394 /* 395 * Set the input to take input from a file. If push is set, push the 396 * old input onto the stack first. 397 */ 398 399 void 400 setinputfile(const char *fname, int push) 401 { 402 int fd; 403 int fd2; 404 405 INTOFF; 406 if ((fd = open(fname, O_RDONLY)) < 0) 407 error("cannot open %s: %s", fname, strerror(errno)); 408 if (fd < 10) { 409 fd2 = fcntl(fd, F_DUPFD, 10); 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 */ 424 425 void 426 setinputfd(int fd, int push) 427 { 428 (void)fcntl(fd, F_SETFD, FD_CLOEXEC); 429 if (push) { 430 pushfile(); 431 parsefile->buf = ckmalloc(BUFSIZ + 1); 432 } 433 if (parsefile->fd > 0) 434 close(parsefile->fd); 435 parsefile->fd = fd; 436 if (parsefile->buf == NULL) 437 parsefile->buf = ckmalloc(BUFSIZ + 1); 438 parselleft = parsenleft = 0; 439 plinno = 1; 440 } 441 442 443 /* 444 * Like setinputfile, but takes input from a string. 445 */ 446 447 void 448 setinputstring(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 */ 466 467 static void 468 pushfile(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 } 483 484 485 void 486 popfile(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 current file (to go back to it later using popfilesupto()). 509 */ 510 511 struct parsefile * 512 getcurrentfile(void) 513 { 514 return parsefile; 515 } 516 517 518 /* 519 * Pop files until the given file is on top again. Useful for regular 520 * builtins that read shell commands from files or strings. 521 * If the given file is not an active file, an error is raised. 522 */ 523 524 void 525 popfilesupto(struct parsefile *file) 526 { 527 while (parsefile != file && parsefile != &basepf) 528 popfile(); 529 if (parsefile != file) 530 error("popfilesupto() misused"); 531 } 532 533 /* 534 * Return to top level. 535 */ 536 537 void 538 popallfiles(void) 539 { 540 while (parsefile != &basepf) 541 popfile(); 542 } 543 544 545 546 /* 547 * Close the file(s) that the shell is reading commands from. Called 548 * after a fork is done. 549 */ 550 551 void 552 closescript(void) 553 { 554 popallfiles(); 555 if (parsefile->fd > 0) { 556 close(parsefile->fd); 557 parsefile->fd = 0; 558 } 559 } 560