input.c revision 124780
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 37#ifndef lint 38#if 0 39static char sccsid[] = "@(#)input.c 8.3 (Berkeley) 6/9/95"; 40#endif 41#endif /* not lint */ 42#include <sys/cdefs.h> 43__FBSDID("$FreeBSD: head/bin/sh/input.c 124780 2004-01-21 12:50:01Z des $"); 44 45#include <stdio.h> /* defines BUFSIZ */ 46#include <fcntl.h> 47#include <errno.h> 48#include <unistd.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#include "trap.h" 68 69#define EOF_NLEFT -99 /* value of parsenleft when EOF pushed back */ 70 71MKINIT 72struct strpush { 73 struct strpush *prev; /* preceding string on stack */ 74 char *prevstring; 75 int prevnleft; 76 int prevlleft; 77 struct alias *ap; /* if push was associated with an alias */ 78}; 79 80/* 81 * The parsefile structure pointed to by the global variable parsefile 82 * contains information about the current file being read. 83 */ 84 85MKINIT 86struct parsefile { 87 struct parsefile *prev; /* preceding file on stack */ 88 int linno; /* current line */ 89 int fd; /* file descriptor (or -1 if string) */ 90 int nleft; /* number of chars left in this line */ 91 int lleft; /* number of lines left in this buffer */ 92 char *nextc; /* next char in buffer */ 93 char *buf; /* input buffer */ 94 struct strpush *strpush; /* for pushing strings at this level */ 95 struct strpush basestrpush; /* so pushing one is fast */ 96}; 97 98 99int plinno = 1; /* input line number */ 100MKINIT int parsenleft; /* copy of parsefile->nleft */ 101MKINIT int parselleft; /* copy of parsefile->lleft */ 102char *parsenextc; /* copy of parsefile->nextc */ 103MKINIT struct parsefile basepf; /* top level input file */ 104char basebuf[BUFSIZ]; /* buffer for top level input file */ 105STATIC struct parsefile *parsefile = &basepf; /* current input file */ 106int init_editline = 0; /* editline library initialized? */ 107int whichprompt; /* 1 == PS1, 2 == PS2 */ 108 109EditLine *el; /* cookie for editline package */ 110 111STATIC void pushfile(void); 112static int preadfd(void); 113 114#ifdef mkinit 115INCLUDE "input.h" 116INCLUDE "error.h" 117 118INIT { 119 extern char basebuf[]; 120 121 basepf.nextc = basepf.buf = basebuf; 122} 123 124RESET { 125 if (exception != EXSHELLPROC) 126 parselleft = parsenleft = 0; /* clear input buffer */ 127 popallfiles(); 128} 129 130SHELLPROC { 131 popallfiles(); 132} 133#endif 134 135 136/* 137 * Read a line from the script. 138 */ 139 140char * 141pfgets(char *line, int len) 142{ 143 char *p = line; 144 int nleft = len; 145 int c; 146 147 while (--nleft > 0) { 148 c = pgetc_macro(); 149 if (c == PEOF) { 150 if (p == line) 151 return NULL; 152 break; 153 } 154 *p++ = c; 155 if (c == '\n') 156 break; 157 } 158 *p = '\0'; 159 return line; 160} 161 162 163 164/* 165 * Read a character from the script, returning PEOF on end of file. 166 * Nul characters in the input are silently discarded. 167 */ 168 169int 170pgetc(void) 171{ 172 return pgetc_macro(); 173} 174 175 176static int 177preadfd(void) 178{ 179 int nr; 180 parsenextc = parsefile->buf; 181 182#ifndef NO_HISTORY 183 if (el != NULL && gotwinch) { 184 gotwinch = 0; 185 el_resize(el); 186 } 187#endif 188retry: 189#ifndef NO_HISTORY 190 if (parsefile->fd == 0 && el) { 191 const char *rl_cp; 192 193 rl_cp = el_gets(el, &nr); 194 if (rl_cp == NULL) 195 nr = 0; 196 else { 197 /* XXX - BUFSIZE should redesign so not necessary */ 198 (void) strcpy(parsenextc, rl_cp); 199 } 200 } else 201#endif 202 nr = read(parsefile->fd, parsenextc, BUFSIZ - 1); 203 204 if (nr <= 0) { 205 if (nr < 0) { 206 if (errno == EINTR) 207 goto retry; 208 if (parsefile->fd == 0 && errno == EWOULDBLOCK) { 209 int flags = fcntl(0, F_GETFL, 0); 210 if (flags >= 0 && flags & O_NONBLOCK) { 211 flags &=~ O_NONBLOCK; 212 if (fcntl(0, F_SETFL, flags) >= 0) { 213 out2str("sh: turning off NDELAY mode\n"); 214 goto retry; 215 } 216 } 217 } 218 } 219 nr = -1; 220 } 221 return nr; 222} 223 224/* 225 * Refill the input buffer and return the next input character: 226 * 227 * 1) If a string was pushed back on the input, pop it; 228 * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading 229 * from a string so we can't refill the buffer, return EOF. 230 * 3) If there is more in this buffer, use it else call read to fill it. 231 * 4) Process input up to the next newline, deleting nul characters. 232 */ 233 234int 235preadbuffer(void) 236{ 237 char *p, *q; 238 int more; 239 int something; 240 char savec; 241 242 if (parsefile->strpush) { 243 popstring(); 244 if (--parsenleft >= 0) 245 return (*parsenextc++); 246 } 247 if (parsenleft == EOF_NLEFT || parsefile->buf == NULL) 248 return PEOF; 249 flushout(&output); 250 flushout(&errout); 251 252again: 253 if (parselleft <= 0) { 254 if ((parselleft = preadfd()) == -1) { 255 parselleft = parsenleft = EOF_NLEFT; 256 return PEOF; 257 } 258 } 259 260 q = p = parsenextc; 261 262 /* delete nul characters */ 263 something = 0; 264 for (more = 1; more;) { 265 switch (*p) { 266 case '\0': 267 p++; /* Skip nul */ 268 goto check; 269 270 case '\t': 271 case ' ': 272 break; 273 274 case '\n': 275 parsenleft = q - parsenextc; 276 more = 0; /* Stop processing here */ 277 break; 278 279 default: 280 something = 1; 281 break; 282 } 283 284 *q++ = *p++; 285check: 286 if (--parselleft <= 0) { 287 parsenleft = q - parsenextc - 1; 288 if (parsenleft < 0) 289 goto again; 290 *q = '\0'; 291 more = 0; 292 } 293 } 294 295 savec = *q; 296 *q = '\0'; 297 298#ifndef NO_HISTORY 299 if (parsefile->fd == 0 && hist && something) { 300 HistEvent he; 301 INTOFF; 302 history(hist, &he, whichprompt == 1 ? H_ENTER : H_ADD, 303 parsenextc); 304 INTON; 305 } 306#endif 307 308 if (vflag) { 309 out2str(parsenextc); 310 flushout(out2); 311 } 312 313 *q = savec; 314 315 return *parsenextc++; 316} 317 318/* 319 * Undo the last call to pgetc. Only one character may be pushed back. 320 * PEOF may be pushed back. 321 */ 322 323void 324pungetc(void) 325{ 326 parsenleft++; 327 parsenextc--; 328} 329 330/* 331 * Push a string back onto the input at this current parsefile level. 332 * We handle aliases this way. 333 */ 334void 335pushstring(char *s, int len, void *ap) 336{ 337 struct strpush *sp; 338 339 INTOFF; 340/*dprintf("*** calling pushstring: %s, %d\n", s, len);*/ 341 if (parsefile->strpush) { 342 sp = ckmalloc(sizeof (struct strpush)); 343 sp->prev = parsefile->strpush; 344 parsefile->strpush = sp; 345 } else 346 sp = parsefile->strpush = &(parsefile->basestrpush); 347 sp->prevstring = parsenextc; 348 sp->prevnleft = parsenleft; 349 sp->prevlleft = parselleft; 350 sp->ap = (struct alias *)ap; 351 if (ap) 352 ((struct alias *)ap)->flag |= ALIASINUSE; 353 parsenextc = s; 354 parsenleft = len; 355 INTON; 356} 357 358void 359popstring(void) 360{ 361 struct strpush *sp = parsefile->strpush; 362 363 INTOFF; 364 parsenextc = sp->prevstring; 365 parsenleft = sp->prevnleft; 366 parselleft = sp->prevlleft; 367/*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/ 368 if (sp->ap) 369 sp->ap->flag &= ~ALIASINUSE; 370 parsefile->strpush = sp->prev; 371 if (sp != &(parsefile->basestrpush)) 372 ckfree(sp); 373 INTON; 374} 375 376/* 377 * Set the input to take input from a file. If push is set, push the 378 * old input onto the stack first. 379 */ 380 381void 382setinputfile(char *fname, int push) 383{ 384 int fd; 385 int fd2; 386 387 INTOFF; 388 if ((fd = open(fname, O_RDONLY)) < 0) 389 error("Can't open %s: %s", fname, strerror(errno)); 390 if (fd < 10) { 391 fd2 = fcntl(fd, F_DUPFD, 10); 392 close(fd); 393 if (fd2 < 0) 394 error("Out of file descriptors"); 395 fd = fd2; 396 } 397 setinputfd(fd, push); 398 INTON; 399} 400 401 402/* 403 * Like setinputfile, but takes an open file descriptor. Call this with 404 * interrupts off. 405 */ 406 407void 408setinputfd(int fd, int push) 409{ 410 (void)fcntl(fd, F_SETFD, FD_CLOEXEC); 411 if (push) { 412 pushfile(); 413 parsefile->buf = ckmalloc(BUFSIZ); 414 } 415 if (parsefile->fd > 0) 416 close(parsefile->fd); 417 parsefile->fd = fd; 418 if (parsefile->buf == NULL) 419 parsefile->buf = ckmalloc(BUFSIZ); 420 parselleft = parsenleft = 0; 421 plinno = 1; 422} 423 424 425/* 426 * Like setinputfile, but takes input from a string. 427 */ 428 429void 430setinputstring(char *string, int push) 431{ 432 INTOFF; 433 if (push) 434 pushfile(); 435 parsenextc = string; 436 parselleft = parsenleft = strlen(string); 437 parsefile->buf = NULL; 438 plinno = 1; 439 INTON; 440} 441 442 443 444/* 445 * To handle the "." command, a stack of input files is used. Pushfile 446 * adds a new entry to the stack and popfile restores the previous level. 447 */ 448 449STATIC void 450pushfile(void) 451{ 452 struct parsefile *pf; 453 454 parsefile->nleft = parsenleft; 455 parsefile->lleft = parselleft; 456 parsefile->nextc = parsenextc; 457 parsefile->linno = plinno; 458 pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile)); 459 pf->prev = parsefile; 460 pf->fd = -1; 461 pf->strpush = NULL; 462 pf->basestrpush.prev = NULL; 463 parsefile = pf; 464} 465 466 467void 468popfile(void) 469{ 470 struct parsefile *pf = parsefile; 471 472 INTOFF; 473 if (pf->fd >= 0) 474 close(pf->fd); 475 if (pf->buf) 476 ckfree(pf->buf); 477 while (pf->strpush) 478 popstring(); 479 parsefile = pf->prev; 480 ckfree(pf); 481 parsenleft = parsefile->nleft; 482 parselleft = parsefile->lleft; 483 parsenextc = parsefile->nextc; 484 plinno = parsefile->linno; 485 INTON; 486} 487 488 489/* 490 * Return to top level. 491 */ 492 493void 494popallfiles(void) 495{ 496 while (parsefile != &basepf) 497 popfile(); 498} 499 500 501 502/* 503 * Close the file(s) that the shell is reading commands from. Called 504 * after a fork is done. 505 */ 506 507void 508closescript(void) 509{ 510 popallfiles(); 511 if (parsefile->fd > 0) { 512 close(parsefile->fd); 513 parsefile->fd = 0; 514 } 515} 516