input.c revision 53891
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 41static const char rcsid[] = 42 "$FreeBSD: head/bin/sh/input.c 53891 1999-11-29 19:11:01Z cracauer $"; 43#endif /* not lint */ 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 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 lines 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 */ 99MKINIT int 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 */ 103char 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 108EditLine *el; /* cookie for editline package */ 109 110STATIC void pushfile __P((void)); 111static int preadfd __P((void)); 112 113#ifdef mkinit 114INCLUDE "input.h" 115INCLUDE "error.h" 116 117INIT { 118 extern char basebuf[]; 119 120 basepf.nextc = basepf.buf = basebuf; 121} 122 123RESET { 124 if (exception != EXSHELLPROC) 125 parselleft = parsenleft = 0; /* clear input buffer */ 126 popallfiles(); 127} 128 129SHELLPROC { 130 popallfiles(); 131} 132#endif 133 134 135/* 136 * Read a line from the script. 137 */ 138 139char * 140pfgets(line, len) 141 char *line; 142 int len; 143{ 144 char *p = line; 145 int nleft = len; 146 int c; 147 148 while (--nleft > 0) { 149 c = pgetc_macro(); 150 if (c == PEOF) { 151 if (p == line) 152 return NULL; 153 break; 154 } 155 *p++ = c; 156 if (c == '\n') 157 break; 158 } 159 *p = '\0'; 160 return line; 161} 162 163 164 165/* 166 * Read a character from the script, returning PEOF on end of file. 167 * Nul characters in the input are silently discarded. 168 */ 169 170int 171pgetc() 172{ 173 return pgetc_macro(); 174} 175 176 177static int 178preadfd() 179{ 180 int nr; 181 parsenextc = parsefile->buf; 182 183retry: 184#ifndef NO_HISTORY 185 if (parsefile->fd == 0 && el) { 186 const char *rl_cp; 187 188 rl_cp = el_gets(el, &nr); 189 if (rl_cp == NULL) 190 nr = 0; 191 else { 192 /* XXX - BUFSIZE should redesign so not necessary */ 193 (void) strcpy(parsenextc, rl_cp); 194 } 195 } else 196#endif 197 nr = read(parsefile->fd, parsenextc, BUFSIZ - 1); 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 out2str("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 229int 230preadbuffer() 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 247again: 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++; 280check: 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 INTOFF; 296 history(hist, whichprompt == 1 ? H_ENTER : H_ADD, parsenextc); 297 INTON; 298 } 299#endif 300 301 if (vflag) { 302 out2str(parsenextc); 303 flushout(out2); 304 } 305 306 *q = savec; 307 308 return *parsenextc++; 309} 310 311/* 312 * Undo the last call to pgetc. Only one character may be pushed back. 313 * PEOF may be pushed back. 314 */ 315 316void 317pungetc() { 318 parsenleft++; 319 parsenextc--; 320} 321 322/* 323 * Push a string back onto the input at this current parsefile level. 324 * We handle aliases this way. 325 */ 326void 327pushstring(s, len, ap) 328 char *s; 329 int len; 330 void *ap; 331 { 332 struct strpush *sp; 333 334 INTOFF; 335/*dprintf("*** calling pushstring: %s, %d\n", s, len);*/ 336 if (parsefile->strpush) { 337 sp = ckmalloc(sizeof (struct strpush)); 338 sp->prev = parsefile->strpush; 339 parsefile->strpush = sp; 340 } else 341 sp = parsefile->strpush = &(parsefile->basestrpush); 342 sp->prevstring = parsenextc; 343 sp->prevnleft = parsenleft; 344 sp->prevlleft = parselleft; 345 sp->ap = (struct alias *)ap; 346 if (ap) 347 ((struct alias *)ap)->flag |= ALIASINUSE; 348 parsenextc = s; 349 parsenleft = len; 350 INTON; 351} 352 353void 354popstring() 355{ 356 struct strpush *sp = parsefile->strpush; 357 358 INTOFF; 359 parsenextc = sp->prevstring; 360 parsenleft = sp->prevnleft; 361 parselleft = sp->prevlleft; 362/*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/ 363 if (sp->ap) 364 sp->ap->flag &= ~ALIASINUSE; 365 parsefile->strpush = sp->prev; 366 if (sp != &(parsefile->basestrpush)) 367 ckfree(sp); 368 INTON; 369} 370 371/* 372 * Set the input to take input from a file. If push is set, push the 373 * old input onto the stack first. 374 */ 375 376void 377setinputfile(fname, push) 378 char *fname; 379 int push; 380{ 381 int fd; 382 int fd2; 383 384 INTOFF; 385 if ((fd = open(fname, O_RDONLY)) < 0) 386 error("Can't open %s: %s", fname, strerror(errno)); 387 if (fd < 10) { 388 fd2 = copyfd(fd, 10); 389 close(fd); 390 if (fd2 < 0) 391 error("Out of file descriptors"); 392 fd = fd2; 393 } 394 setinputfd(fd, push); 395 INTON; 396} 397 398 399/* 400 * Like setinputfile, but takes an open file descriptor. Call this with 401 * interrupts off. 402 */ 403 404void 405setinputfd(fd, push) 406 int fd, push; 407{ 408 (void)fcntl(fd, F_SETFD, FD_CLOEXEC); 409 if (push) { 410 pushfile(); 411 parsefile->buf = ckmalloc(BUFSIZ); 412 } 413 if (parsefile->fd > 0) 414 close(parsefile->fd); 415 parsefile->fd = fd; 416 if (parsefile->buf == NULL) 417 parsefile->buf = ckmalloc(BUFSIZ); 418 parselleft = parsenleft = 0; 419 plinno = 1; 420} 421 422 423/* 424 * Like setinputfile, but takes input from a string. 425 */ 426 427void 428setinputstring(string, push) 429 char *string; 430 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() { 451 struct parsefile *pf; 452 453 parsefile->nleft = parsenleft; 454 parsefile->lleft = parselleft; 455 parsefile->nextc = parsenextc; 456 parsefile->linno = plinno; 457 pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile)); 458 pf->prev = parsefile; 459 pf->fd = -1; 460 pf->strpush = NULL; 461 pf->basestrpush.prev = NULL; 462 parsefile = pf; 463} 464 465 466void 467popfile() { 468 struct parsefile *pf = parsefile; 469 470 INTOFF; 471 if (pf->fd >= 0) 472 close(pf->fd); 473 if (pf->buf) 474 ckfree(pf->buf); 475 while (pf->strpush) 476 popstring(); 477 parsefile = pf->prev; 478 ckfree(pf); 479 parsenleft = parsefile->nleft; 480 parselleft = parsefile->lleft; 481 parsenextc = parsefile->nextc; 482 plinno = parsefile->linno; 483 INTON; 484} 485 486 487/* 488 * Return to top level. 489 */ 490 491void 492popallfiles() { 493 while (parsefile != &basepf) 494 popfile(); 495} 496 497 498 499/* 500 * Close the file(s) that the shell is reading commands from. Called 501 * after a fork is done. 502 */ 503 504void 505closescript() { 506 popallfiles(); 507 if (parsefile->fd > 0) { 508 close(parsefile->fd); 509 parsefile->fd = 0; 510 } 511} 512