input.c revision 1.29
1/* $NetBSD: input.c,v 1.29 1998/03/29 04:41:44 mrg 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. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the University of 21 * California, Berkeley and its contributors. 22 * 4. Neither the name of the University nor the names of its contributors 23 * may be used to endorse or promote products derived from this software 24 * without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36 * SUCH DAMAGE. 37 */ 38 39#include <sys/cdefs.h> 40#ifndef lint 41#if 0 42static char sccsid[] = "@(#)input.c 8.3 (Berkeley) 6/9/95"; 43#else 44__RCSID("$NetBSD: input.c,v 1.29 1998/03/29 04:41:44 mrg Exp $"); 45#endif 46#endif /* not lint */ 47 48#include <stdio.h> /* defines BUFSIZ */ 49#include <fcntl.h> 50#include <errno.h> 51#include <unistd.h> 52#include <stdlib.h> 53#include <string.h> 54 55/* 56 * This file implements the input routines used by the parser. 57 */ 58 59#include "shell.h" 60#include "redir.h" 61#include "syntax.h" 62#include "input.h" 63#include "output.h" 64#include "options.h" 65#include "memalloc.h" 66#include "error.h" 67#include "alias.h" 68#include "parser.h" 69#include "myhistedit.h" 70 71#define EOF_NLEFT -99 /* value of parsenleft when EOF pushed back */ 72 73MKINIT 74struct strpush { 75 struct strpush *prev; /* preceding string on stack */ 76 char *prevstring; 77 int prevnleft; 78 int prevlleft; 79 struct alias *ap; /* if push was associated with an alias */ 80}; 81 82/* 83 * The parsefile structure pointed to by the global variable parsefile 84 * contains information about the current file being read. 85 */ 86 87MKINIT 88struct parsefile { 89 struct parsefile *prev; /* preceding file on stack */ 90 int linno; /* current line */ 91 int fd; /* file descriptor (or -1 if string) */ 92 int nleft; /* number of chars left in this line */ 93 int lleft; /* number of chars left in this buffer */ 94 char *nextc; /* next char in buffer */ 95 char *buf; /* input buffer */ 96 struct strpush *strpush; /* for pushing strings at this level */ 97 struct strpush basestrpush; /* so pushing one is fast */ 98}; 99 100 101int plinno = 1; /* input line number */ 102MKINIT int parsenleft; /* copy of parsefile->nleft */ 103MKINIT int parselleft; /* copy of parsefile->lleft */ 104char *parsenextc; /* copy of parsefile->nextc */ 105MKINIT struct parsefile basepf; /* top level input file */ 106char basebuf[BUFSIZ]; /* buffer for top level input file */ 107struct parsefile *parsefile = &basepf; /* current input file */ 108int init_editline = 0; /* editline library initialized? */ 109int whichprompt; /* 1 == PS1, 2 == PS2 */ 110 111EditLine *el; /* cookie for editline package */ 112 113STATIC void pushfile __P((void)); 114static int preadfd __P((void)); 115 116#ifdef mkinit 117INCLUDE "input.h" 118INCLUDE "error.h" 119 120INIT { 121 extern char basebuf[]; 122 123 basepf.nextc = basepf.buf = basebuf; 124} 125 126RESET { 127 if (exception != EXSHELLPROC) 128 parselleft = parsenleft = 0; /* clear input buffer */ 129 popallfiles(); 130} 131 132SHELLPROC { 133 popallfiles(); 134} 135#endif 136 137 138/* 139 * Read a line from the script. 140 */ 141 142char * 143pfgets(line, len) 144 char *line; 145 int len; 146{ 147 char *p = line; 148 int nleft = len; 149 int c; 150 151 while (--nleft > 0) { 152 c = pgetc_macro(); 153 if (c == PEOF) { 154 if (p == line) 155 return NULL; 156 break; 157 } 158 *p++ = c; 159 if (c == '\n') 160 break; 161 } 162 *p = '\0'; 163 return line; 164} 165 166 167 168/* 169 * Read a character from the script, returning PEOF on end of file. 170 * Nul characters in the input are silently discarded. 171 */ 172 173int 174pgetc() 175{ 176 return pgetc_macro(); 177} 178 179 180static int 181preadfd() 182{ 183 int nr; 184 parsenextc = parsefile->buf; 185 186retry: 187#ifndef SMALL 188 if (parsefile->fd == 0 && el) { 189 const char *rl_cp; 190 191 rl_cp = el_gets(el, &nr); 192 if (rl_cp == NULL) 193 nr = 0; 194 else { 195 /* XXX - BUFSIZE should redesign so not necessary */ 196 (void) strcpy(parsenextc, rl_cp); 197 } 198 } else 199#endif 200 nr = read(parsefile->fd, parsenextc, BUFSIZ - 1); 201 202 203 if (nr <= 0) { 204 if (nr < 0) { 205 if (errno == EINTR) 206 goto retry; 207 if (parsefile->fd == 0 && errno == EWOULDBLOCK) { 208 int flags = fcntl(0, F_GETFL, 0); 209 if (flags >= 0 && flags & O_NONBLOCK) { 210 flags &=~ O_NONBLOCK; 211 if (fcntl(0, F_SETFL, flags) >= 0) { 212 out2str("sh: turning off NDELAY mode\n"); 213 goto retry; 214 } 215 } 216 } 217 } 218 nr = -1; 219 } 220 return nr; 221} 222 223/* 224 * Refill the input buffer and return the next input character: 225 * 226 * 1) If a string was pushed back on the input, pop it; 227 * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading 228 * from a string so we can't refill the buffer, return EOF. 229 * 3) If the is more stuff in this buffer, use it else call read to fill it. 230 * 4) Process input up to the next newline, deleting nul characters. 231 */ 232 233int 234preadbuffer() 235{ 236 char *p, *q; 237 int more; 238 int something; 239 char savec; 240 241 if (parsefile->strpush) { 242 popstring(); 243 if (--parsenleft >= 0) 244 return (*parsenextc++); 245 } 246 if (parsenleft == EOF_NLEFT || parsefile->buf == NULL) 247 return PEOF; 248 flushout(&output); 249 flushout(&errout); 250 251again: 252 if (parselleft <= 0) { 253 if ((parselleft = preadfd()) == -1) { 254 parselleft = parsenleft = EOF_NLEFT; 255 return PEOF; 256 } 257 } 258 259 q = p = parsenextc; 260 261 /* delete nul characters */ 262 something = 0; 263 for (more = 1; more;) { 264 switch (*p) { 265 case '\0': 266 p++; /* Skip nul */ 267 goto check; 268 269 case '\t': 270 case ' ': 271 break; 272 273 case '\n': 274 parsenleft = q - parsenextc; 275 more = 0; /* Stop processing here */ 276 break; 277 278 default: 279 something = 1; 280 break; 281 } 282 283 *q++ = *p++; 284check: 285 if (--parselleft <= 0) { 286 parsenleft = q - parsenextc - 1; 287 if (parsenleft < 0) 288 goto again; 289 *q = '\0'; 290 more = 0; 291 } 292 } 293 294 savec = *q; 295 *q = '\0'; 296 297#ifndef SMALL 298 if (parsefile->fd == 0 && hist && something) { 299 HistEvent he; 300 INTOFF; 301 history(hist, &he, 302 whichprompt == 1 ? H_ENTER : H_ADD, parsenextc); 303 INTON; 304 } 305#endif 306 307 if (vflag) { 308 out2str(parsenextc); 309 flushout(out2); 310 } 311 312 *q = savec; 313 314 return *parsenextc++; 315} 316 317/* 318 * Undo the last call to pgetc. Only one character may be pushed back. 319 * PEOF may be pushed back. 320 */ 321 322void 323pungetc() { 324 parsenleft++; 325 parsenextc--; 326} 327 328/* 329 * Push a string back onto the input at this current parsefile level. 330 * We handle aliases this way. 331 */ 332void 333pushstring(s, len, ap) 334 char *s; 335 int len; 336 void *ap; 337 { 338 struct strpush *sp; 339 340 INTOFF; 341/*dprintf("*** calling pushstring: %s, %d\n", s, len);*/ 342 if (parsefile->strpush) { 343 sp = ckmalloc(sizeof (struct strpush)); 344 sp->prev = parsefile->strpush; 345 parsefile->strpush = sp; 346 } else 347 sp = parsefile->strpush = &(parsefile->basestrpush); 348 sp->prevstring = parsenextc; 349 sp->prevnleft = parsenleft; 350 sp->prevlleft = parselleft; 351 sp->ap = (struct alias *)ap; 352 if (ap) 353 ((struct alias *)ap)->flag |= ALIASINUSE; 354 parsenextc = s; 355 parsenleft = len; 356 INTON; 357} 358 359void 360popstring() 361{ 362 struct strpush *sp = parsefile->strpush; 363 364 INTOFF; 365 parsenextc = sp->prevstring; 366 parsenleft = sp->prevnleft; 367 parselleft = sp->prevlleft; 368/*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/ 369 if (sp->ap) 370 sp->ap->flag &= ~ALIASINUSE; 371 parsefile->strpush = sp->prev; 372 if (sp != &(parsefile->basestrpush)) 373 ckfree(sp); 374 INTON; 375} 376 377/* 378 * Set the input to take input from a file. If push is set, push the 379 * old input onto the stack first. 380 */ 381 382void 383setinputfile(fname, push) 384 char *fname; 385 int push; 386{ 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 if (fd < 10) { 394 fd2 = copyfd(fd, 10); 395 close(fd); 396 if (fd2 < 0) 397 error("Out of file descriptors"); 398 fd = fd2; 399 } 400 setinputfd(fd, push); 401 INTON; 402} 403 404 405/* 406 * Like setinputfile, but takes an open file descriptor. Call this with 407 * interrupts off. 408 */ 409 410void 411setinputfd(fd, push) 412 int fd, push; 413{ 414 (void) fcntl(fd, F_SETFD, FD_CLOEXEC); 415 if (push) { 416 pushfile(); 417 parsefile->buf = ckmalloc(BUFSIZ); 418 } 419 if (parsefile->fd > 0) 420 close(parsefile->fd); 421 parsefile->fd = fd; 422 if (parsefile->buf == NULL) 423 parsefile->buf = ckmalloc(BUFSIZ); 424 parselleft = parsenleft = 0; 425 plinno = 1; 426} 427 428 429/* 430 * Like setinputfile, but takes input from a string. 431 */ 432 433void 434setinputstring(string, push) 435 char *string; 436 int push; 437 { 438 INTOFF; 439 if (push) 440 pushfile(); 441 parsenextc = string; 442 parselleft = parsenleft = strlen(string); 443 parsefile->buf = NULL; 444 plinno = 1; 445 INTON; 446} 447 448 449 450/* 451 * To handle the "." command, a stack of input files is used. Pushfile 452 * adds a new entry to the stack and popfile restores the previous level. 453 */ 454 455STATIC void 456pushfile() { 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 472void 473popfile() { 474 struct parsefile *pf = parsefile; 475 476 INTOFF; 477 if (pf->fd >= 0) 478 close(pf->fd); 479 if (pf->buf) 480 ckfree(pf->buf); 481 while (pf->strpush) 482 popstring(); 483 parsefile = pf->prev; 484 ckfree(pf); 485 parsenleft = parsefile->nleft; 486 parselleft = parsefile->lleft; 487 parsenextc = parsefile->nextc; 488 plinno = parsefile->linno; 489 INTON; 490} 491 492 493/* 494 * Return to top level. 495 */ 496 497void 498popallfiles() { 499 while (parsefile != &basepf) 500 popfile(); 501} 502 503 504 505/* 506 * Close the file(s) that the shell is reading commands from. Called 507 * after a fork is done. 508 */ 509 510void 511closescript() { 512 popallfiles(); 513 if (parsefile->fd > 0) { 514 close(parsefile->fd); 515 parsefile->fd = 0; 516 } 517} 518