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 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)input.c 8.3 (Berkeley) 6/9/95 37 * $FreeBSD: head/bin/sh/input.c 245676 2013-01-19 22:12:08Z jilles $ 38 */ 39 40 #include <stdio.h> /* defines BUFSIZ */ 41 #include <fcntl.h> 42 #include <errno.h> 43 #include <unistd.h> 44 #include <stdlib.h> 45 #include <string.h> 46 47 /* 48 * This file implements the input routines used by the parser. 49 */ 50 51 #include "shell.h" 52 #include "redir.h" 53 #include "syntax.h" 54 #include "input.h" 55 #include "output.h" 56 #include "options.h" 57 #include "memalloc.h" 58 #include "error.h" 59 #include "alias.h" 60 #include "parser.h" 61 #include "myhistedit.h" 62 #include "trap.h" 63 64 #define EOF_NLEFT -99 /* value of parsenleft when EOF pushed back */ 65 66 struct strpush { 67 struct strpush *prev; /* preceding string on stack */ 68 char *prevstring; 69 int prevnleft; 70 int prevlleft; 71 struct alias *ap; /* if push was associated with an alias */ 72 }; 73 74 /* 75 * The parsefile structure pointed to by the global variable parsefile 76 * contains information about the current file being read. 77 */ 78 79 struct parsefile { 80 struct parsefile *prev; /* preceding file on stack */ 81 int linno; /* current line */ 82 int fd; /* file descriptor (or -1 if string) */ 83 int nleft; /* number of chars left in this line */ 84 int lleft; /* number of lines left in this buffer */ 85 char *nextc; /* next char in buffer */ 86 char *buf; /* input buffer */ 87 struct strpush *strpush; /* for pushing strings at this level */ 88 struct strpush basestrpush; /* so pushing one is fast */ 89 }; 90 91 92 int plinno = 1; /* input line number */ 93 int parsenleft; /* copy of parsefile->nleft */ 94 MKINIT int parselleft; /* copy of parsefile->lleft */ 95 char *parsenextc; /* copy of parsefile->nextc */ 96 static char basebuf[BUFSIZ + 1];/* buffer for top level input file */ 97 static struct parsefile basepf = { /* top level input file */ 98 .nextc = basebuf, 99 .buf = basebuf 100 }; 101 static struct parsefile *parsefile = &basepf; /* current input file */ 102 int whichprompt; /* 1 == PS1, 2 == PS2 */ 103 104 EditLine *el; /* cookie for editline package */ 105 106 static void pushfile(void); 107 static int preadfd(void); 108 static void popstring(void); 109 110 #ifdef mkinit 111 INCLUDE <stdio.h> 112 INCLUDE "input.h" 113 INCLUDE "error.h" 114 115 RESET { 116 popallfiles(); 117 parselleft = parsenleft = 0; /* clear input buffer */ 118 } 119 #endif 120 121 122 /* 123 * Read a line from the script. 124 */ 125 126 char * 127 pfgets(char *line, int len) 128 { 129 char *p = line; 130 int nleft = len; 131 int c; 132 133 while (--nleft > 0) { 134 c = pgetc_macro(); 135 if (c == PEOF) { 136 if (p == line) 137 return NULL; 138 break; 139 } 140 *p++ = c; 141 if (c == '\n') 142 break; 143 } 144 *p = '\0'; 145 return line; 146 } 147 148 149 150 /* 151 * Read a character from the script, returning PEOF on end of file. 152 * Nul characters in the input are silently discarded. 153 */ 154 155 int 156 pgetc(void) 157 { 158 return pgetc_macro(); 159 } 160 161 162 static int 163 preadfd(void) 164 { 165 int nr; 166 parsenextc = parsefile->buf; 167 168 #ifndef NO_HISTORY 169 if (el != NULL && gotwinch) { 170 gotwinch = 0; 171 el_resize(el); 172 } 173 #endif 174 retry: 175 #ifndef NO_HISTORY 176 if (parsefile->fd == 0 && el) { 177 static const char *rl_cp; 178 static int el_len; 179 180 if (rl_cp == NULL) 181 rl_cp = el_gets(el, &el_len); 182 if (rl_cp == NULL) 183 nr = el_len == 0 ? 0 : -1; 184 else { 185 nr = el_len; 186 if (nr > BUFSIZ) 187 nr = BUFSIZ; 188 memcpy(parsenextc, rl_cp, nr); 189 if (nr != el_len) { 190 el_len -= nr; 191 rl_cp += nr; 192 } else 193 rl_cp = NULL; 194 } 195 } else 196 #endif 197 nr = read(parsefile->fd, parsenextc, BUFSIZ); 198 199 if (nr <= 0) { 200 if (nr < 0) { 201 if (errno == EINTR) 202 goto retry; 203 if (parsefile->fd == 0 && errno == EWOULDBLOCK) { 204 int flags = fcntl(0, F_GETFL, 0); 205 if (flags >= 0 && flags & O_NONBLOCK) { 206 flags &=~ O_NONBLOCK; 207 if (fcntl(0, F_SETFL, flags) >= 0) { 208 out2fmt_flush("sh: turning off NDELAY mode\n"); 209 goto retry; 210 } 211 } 212 } 213 } 214 nr = -1; 215 } 216 return nr; 217 } 218 219 /* 220 * Refill the input buffer and return the next input character: 221 * 222 * 1) If a string was pushed back on the input, pop it; 223 * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading 224 * from a string so we can't refill the buffer, return EOF. 225 * 3) If there is more in this buffer, use it else call read to fill it. 226 * 4) Process input up to the next newline, deleting nul characters. 227 */ 228 229 int 230 preadbuffer(void) 231 { 232 char *p, *q; 233 int more; 234 int something; 235 char savec; 236 237 if (parsefile->strpush) { 238 popstring(); 239 if (--parsenleft >= 0) 240 return (*parsenextc++); 241 } 242 if (parsenleft == EOF_NLEFT || parsefile->buf == NULL) 243 return PEOF; 244 flushout(&output); 245 flushout(&errout); 246 247 again: 248 if (parselleft <= 0) { 249 if ((parselleft = preadfd()) == -1) { 250 parselleft = parsenleft = EOF_NLEFT; 251 return PEOF; 252 } 253 } 254 255 q = p = parsenextc; 256 257 /* delete nul characters */ 258 something = 0; 259 for (more = 1; more;) { 260 switch (*p) { 261 case '\0': 262 p++; /* Skip nul */ 263 goto check; 264 265 case '\t': 266 case ' ': 267 break; 268 269 case '\n': 270 parsenleft = q - parsenextc; 271 more = 0; /* Stop processing here */ 272 break; 273 274 default: 275 something = 1; 276 break; 277 } 278 279 *q++ = *p++; 280 check: 281 if (--parselleft <= 0) { 282 parsenleft = q - parsenextc - 1; 283 if (parsenleft < 0) 284 goto again; 285 *q = '\0'; 286 more = 0; 287 } 288 } 289 290 savec = *q; 291 *q = '\0'; 292 293 #ifndef NO_HISTORY 294 if (parsefile->fd == 0 && hist && something) { 295 HistEvent he; 296 INTOFF; 297 history(hist, &he, whichprompt == 1 ? H_ENTER : H_ADD, 298 parsenextc); 299 INTON; 300 } 301 #endif 302 303 if (vflag) { 304 out2str(parsenextc); 305 flushout(out2); 306 } 307 308 *q = savec; 309 310 return *parsenextc++; 311 } 312 313 /* 314 * Returns if we are certain we are at EOF. Does not cause any more input 315 * to be read from the outside world. 316 */ 317 318 int 319 preadateof(void) 320 { 321 if (parsenleft > 0) 322 return 0; 323 if (parsefile->strpush) 324 return 0; 325 if (parsenleft == EOF_NLEFT || parsefile->buf == NULL) 326 return 1; 327 return 0; 328 } 329 330 /* 331 * Undo the last call to pgetc. Only one character may be pushed back. 332 * PEOF may be pushed back. 333 */ 334 335 void 336 pungetc(void) 337 { 338 parsenleft++; 339 parsenextc--; 340 } 341 342 /* 343 * Push a string back onto the input at this current parsefile level. 344 * We handle aliases this way. 345 */ 346 void 347 pushstring(char *s, int len, struct alias *ap) 348 { 349 struct strpush *sp; 350 351 INTOFF; 352 /*out2fmt_flush("*** calling pushstring: %s, %d\n", s, len);*/ 353 if (parsefile->strpush) { 354 sp = ckmalloc(sizeof (struct strpush)); 355 sp->prev = parsefile->strpush; 356 parsefile->strpush = sp; 357 } else 358 sp = parsefile->strpush = &(parsefile->basestrpush); 359 sp->prevstring = parsenextc; 360 sp->prevnleft = parsenleft; 361 sp->prevlleft = parselleft; 362 sp->ap = ap; 363 if (ap) 364 ap->flag |= ALIASINUSE; 365 parsenextc = s; 366 parsenleft = len; 367 INTON; 368 } 369 370 static void 371 popstring(void) 372 { 373 struct strpush *sp = parsefile->strpush; 374 375 INTOFF; 376 parsenextc = sp->prevstring; 377 parsenleft = sp->prevnleft; 378 parselleft = sp->prevlleft; 379 /*out2fmt_flush("*** calling popstring: restoring to '%s'\n", parsenextc);*/ 380 if (sp->ap) 381 sp->ap->flag &= ~ALIASINUSE; 382 parsefile->strpush = sp->prev; 383 if (sp != &(parsefile->basestrpush)) 384 ckfree(sp); 385 INTON; 386 } 387 388 /* 389 * Set the input to take input from a file. If push is set, push the 390 * old input onto the stack first. 391 */ 392 393 void 394 setinputfile(const char *fname, int push) 395 { 396 int fd; 397 int fd2; 398 399 INTOFF; 400 if ((fd = open(fname, O_RDONLY)) < 0) 401 error("cannot open %s: %s", fname, strerror(errno)); 402 if (fd < 10) { 403 fd2 = fcntl(fd, F_DUPFD, 10); 404 close(fd); 405 if (fd2 < 0) 406 error("Out of file descriptors"); 407 fd = fd2; 408 } 409 setinputfd(fd, push); 410 INTON; 411 } 412 413 414 /* 415 * Like setinputfile, but takes an open file descriptor. Call this with 416 * interrupts off. 417 */ 418 419 void 420 setinputfd(int fd, int push) 421 { 422 fcntl(fd, F_SETFD, FD_CLOEXEC); 423 if (push) { 424 pushfile(); 425 parsefile->buf = ckmalloc(BUFSIZ + 1); 426 } 427 if (parsefile->fd > 0) 428 close(parsefile->fd); 429 parsefile->fd = fd; 430 if (parsefile->buf == NULL) 431 parsefile->buf = ckmalloc(BUFSIZ + 1); 432 parselleft = parsenleft = 0; 433 plinno = 1; 434 } 435 436 437 /* 438 * Like setinputfile, but takes input from a string. 439 */ 440 441 void 442 setinputstring(char *string, int push) 443 { 444 INTOFF; 445 if (push) 446 pushfile(); 447 parsenextc = string; 448 parselleft = parsenleft = strlen(string); 449 parsefile->buf = NULL; 450 plinno = 1; 451 INTON; 452 } 453 454 455 456 /* 457 * To handle the "." command, a stack of input files is used. Pushfile 458 * adds a new entry to the stack and popfile restores the previous level. 459 */ 460 461 static void 462 pushfile(void) 463 { 464 struct parsefile *pf; 465 466 parsefile->nleft = parsenleft; 467 parsefile->lleft = parselleft; 468 parsefile->nextc = parsenextc; 469 parsefile->linno = plinno; 470 pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile)); 471 pf->prev = parsefile; 472 pf->fd = -1; 473 pf->strpush = NULL; 474 pf->basestrpush.prev = NULL; 475 parsefile = pf; 476 } 477 478 479 void 480 popfile(void) 481 { 482 struct parsefile *pf = parsefile; 483 484 INTOFF; 485 if (pf->fd >= 0) 486 close(pf->fd); 487 if (pf->buf) 488 ckfree(pf->buf); 489 while (pf->strpush) 490 popstring(); 491 parsefile = pf->prev; 492 ckfree(pf); 493 parsenleft = parsefile->nleft; 494 parselleft = parsefile->lleft; 495 parsenextc = parsefile->nextc; 496 plinno = parsefile->linno; 497 INTON; 498 } 499 500 501 /* 502 * Return current file (to go back to it later using popfilesupto()). 503 */ 504 505 struct parsefile * 506 getcurrentfile(void) 507 { 508 return parsefile; 509 } 510 511 512 /* 513 * Pop files until the given file is on top again. Useful for regular 514 * builtins that read shell commands from files or strings. 515 * If the given file is not an active file, an error is raised. 516 */ 517 518 void 519 popfilesupto(struct parsefile *file) 520 { 521 while (parsefile != file && parsefile != &basepf) 522 popfile(); 523 if (parsefile != file) 524 error("popfilesupto() misused"); 525 } 526 527 /* 528 * Return to top level. 529 */ 530 531 void 532 popallfiles(void) 533 { 534 while (parsefile != &basepf) 535 popfile(); 536 } 537 538 539 540 /* 541 * Close the file(s) that the shell is reading commands from. Called 542 * after a fork is done. 543 */ 544 545 void 546 closescript(void) 547 { 548 popallfiles(); 549 if (parsefile->fd > 0) { 550 close(parsefile->fd); 551 parsefile->fd = 0; 552 } 553 } 554