input.c revision 99110
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 99110 2002-06-30 05:15:05Z obrien $"); 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(void); 111static int preadfd(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(char *line, int len) 141{ 142 char *p = line; 143 int nleft = len; 144 int c; 145 146 while (--nleft > 0) { 147 c = pgetc_macro(); 148 if (c == PEOF) { 149 if (p == line) 150 return NULL; 151 break; 152 } 153 *p++ = c; 154 if (c == '\n') 155 break; 156 } 157 *p = '\0'; 158 return line; 159} 160 161 162 163/* 164 * Read a character from the script, returning PEOF on end of file. 165 * Nul characters in the input are silently discarded. 166 */ 167 168int 169pgetc(void) 170{ 171 return pgetc_macro(); 172} 173 174 175static int 176preadfd(void) 177{ 178 int nr; 179 parsenextc = parsefile->buf; 180 181retry: 182#ifndef NO_HISTORY 183 if (parsefile->fd == 0 && el) { 184 const char *rl_cp; 185 186 rl_cp = el_gets(el, &nr); 187 if (rl_cp == NULL) 188 nr = 0; 189 else { 190 /* XXX - BUFSIZE should redesign so not necessary */ 191 (void) strcpy(parsenextc, rl_cp); 192 } 193 } else 194#endif 195 nr = read(parsefile->fd, parsenextc, BUFSIZ - 1); 196 197 if (nr <= 0) { 198 if (nr < 0) { 199 if (errno == EINTR) 200 goto retry; 201 if (parsefile->fd == 0 && errno == EWOULDBLOCK) { 202 int flags = fcntl(0, F_GETFL, 0); 203 if (flags >= 0 && flags & O_NONBLOCK) { 204 flags &=~ O_NONBLOCK; 205 if (fcntl(0, F_SETFL, flags) >= 0) { 206 out2str("sh: turning off NDELAY mode\n"); 207 goto retry; 208 } 209 } 210 } 211 } 212 nr = -1; 213 } 214 return nr; 215} 216 217/* 218 * Refill the input buffer and return the next input character: 219 * 220 * 1) If a string was pushed back on the input, pop it; 221 * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading 222 * from a string so we can't refill the buffer, return EOF. 223 * 3) If there is more in this buffer, use it else call read to fill it. 224 * 4) Process input up to the next newline, deleting nul characters. 225 */ 226 227int 228preadbuffer(void) 229{ 230 char *p, *q; 231 int more; 232 int something; 233 char savec; 234 235 if (parsefile->strpush) { 236 popstring(); 237 if (--parsenleft >= 0) 238 return (*parsenextc++); 239 } 240 if (parsenleft == EOF_NLEFT || parsefile->buf == NULL) 241 return PEOF; 242 flushout(&output); 243 flushout(&errout); 244 245again: 246 if (parselleft <= 0) { 247 if ((parselleft = preadfd()) == -1) { 248 parselleft = parsenleft = EOF_NLEFT; 249 return PEOF; 250 } 251 } 252 253 q = p = parsenextc; 254 255 /* delete nul characters */ 256 something = 0; 257 for (more = 1; more;) { 258 switch (*p) { 259 case '\0': 260 p++; /* Skip nul */ 261 goto check; 262 263 case '\t': 264 case ' ': 265 break; 266 267 case '\n': 268 parsenleft = q - parsenextc; 269 more = 0; /* Stop processing here */ 270 break; 271 272 default: 273 something = 1; 274 break; 275 } 276 277 *q++ = *p++; 278check: 279 if (--parselleft <= 0) { 280 parsenleft = q - parsenextc - 1; 281 if (parsenleft < 0) 282 goto again; 283 *q = '\0'; 284 more = 0; 285 } 286 } 287 288 savec = *q; 289 *q = '\0'; 290 291#ifndef NO_HISTORY 292 if (parsefile->fd == 0 && hist && something) { 293 HistEvent he; 294 INTOFF; 295 history(hist, &he, whichprompt == 1 ? H_ENTER : H_ADD, 296 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(void) 318{ 319 parsenleft++; 320 parsenextc--; 321} 322 323/* 324 * Push a string back onto the input at this current parsefile level. 325 * We handle aliases this way. 326 */ 327void 328pushstring(char *s, int len, void *ap) 329{ 330 struct strpush *sp; 331 332 INTOFF; 333/*dprintf("*** calling pushstring: %s, %d\n", s, len);*/ 334 if (parsefile->strpush) { 335 sp = ckmalloc(sizeof (struct strpush)); 336 sp->prev = parsefile->strpush; 337 parsefile->strpush = sp; 338 } else 339 sp = parsefile->strpush = &(parsefile->basestrpush); 340 sp->prevstring = parsenextc; 341 sp->prevnleft = parsenleft; 342 sp->prevlleft = parselleft; 343 sp->ap = (struct alias *)ap; 344 if (ap) 345 ((struct alias *)ap)->flag |= ALIASINUSE; 346 parsenextc = s; 347 parsenleft = len; 348 INTON; 349} 350 351void 352popstring(void) 353{ 354 struct strpush *sp = parsefile->strpush; 355 356 INTOFF; 357 parsenextc = sp->prevstring; 358 parsenleft = sp->prevnleft; 359 parselleft = sp->prevlleft; 360/*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/ 361 if (sp->ap) 362 sp->ap->flag &= ~ALIASINUSE; 363 parsefile->strpush = sp->prev; 364 if (sp != &(parsefile->basestrpush)) 365 ckfree(sp); 366 INTON; 367} 368 369/* 370 * Set the input to take input from a file. If push is set, push the 371 * old input onto the stack first. 372 */ 373 374void 375setinputfile(char *fname, int push) 376{ 377 int fd; 378 int fd2; 379 380 INTOFF; 381 if ((fd = open(fname, O_RDONLY)) < 0) 382 error("Can't open %s: %s", fname, strerror(errno)); 383 if (fd < 10) { 384 fd2 = copyfd(fd, 10); 385 close(fd); 386 if (fd2 < 0) 387 error("Out of file descriptors"); 388 fd = fd2; 389 } 390 setinputfd(fd, push); 391 INTON; 392} 393 394 395/* 396 * Like setinputfile, but takes an open file descriptor. Call this with 397 * interrupts off. 398 */ 399 400void 401setinputfd(int fd, int push) 402{ 403 (void)fcntl(fd, F_SETFD, FD_CLOEXEC); 404 if (push) { 405 pushfile(); 406 parsefile->buf = ckmalloc(BUFSIZ); 407 } 408 if (parsefile->fd > 0) 409 close(parsefile->fd); 410 parsefile->fd = fd; 411 if (parsefile->buf == NULL) 412 parsefile->buf = ckmalloc(BUFSIZ); 413 parselleft = parsenleft = 0; 414 plinno = 1; 415} 416 417 418/* 419 * Like setinputfile, but takes input from a string. 420 */ 421 422void 423setinputstring(char *string, int push) 424{ 425 INTOFF; 426 if (push) 427 pushfile(); 428 parsenextc = string; 429 parselleft = parsenleft = strlen(string); 430 parsefile->buf = NULL; 431 plinno = 1; 432 INTON; 433} 434 435 436 437/* 438 * To handle the "." command, a stack of input files is used. Pushfile 439 * adds a new entry to the stack and popfile restores the previous level. 440 */ 441 442STATIC void 443pushfile(void) 444{ 445 struct parsefile *pf; 446 447 parsefile->nleft = parsenleft; 448 parsefile->lleft = parselleft; 449 parsefile->nextc = parsenextc; 450 parsefile->linno = plinno; 451 pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile)); 452 pf->prev = parsefile; 453 pf->fd = -1; 454 pf->strpush = NULL; 455 pf->basestrpush.prev = NULL; 456 parsefile = pf; 457} 458 459 460void 461popfile(void) 462{ 463 struct parsefile *pf = parsefile; 464 465 INTOFF; 466 if (pf->fd >= 0) 467 close(pf->fd); 468 if (pf->buf) 469 ckfree(pf->buf); 470 while (pf->strpush) 471 popstring(); 472 parsefile = pf->prev; 473 ckfree(pf); 474 parsenleft = parsefile->nleft; 475 parselleft = parsefile->lleft; 476 parsenextc = parsefile->nextc; 477 plinno = parsefile->linno; 478 INTON; 479} 480 481 482/* 483 * Return to top level. 484 */ 485 486void 487popallfiles(void) 488{ 489 while (parsefile != &basepf) 490 popfile(); 491} 492 493 494 495/* 496 * Close the file(s) that the shell is reading commands from. Called 497 * after a fork is done. 498 */ 499 500void 501closescript(void) 502{ 503 popallfiles(); 504 if (parsefile->fd > 0) { 505 close(parsefile->fd); 506 parsefile->fd = 0; 507 } 508} 509