commands/ash/input.c

   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  * 4. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #ifndef lint
  34 #if 0
  35 static char sccsid[] = "@(#)input.c     8.3 (Berkeley) 6/9/95";
  36 #endif
  37 #endif /* not lint */
  38 #include <sys/cdefs.h>
  39 /*
  40 __FBSDID("$FreeBSD: src/bin/sh/input.c,v 1.22 2004/04/06 20:06:51 markm Exp $");
  41 */
  42
  43 #include <sys/types.h>
  44 #include <stdio.h>      /* defines BUFSIZ */
  45 #include <fcntl.h>
  46 #include <errno.h>
  47 #include <unistd.h>
  48 #include <stdlib.h>
  49 #include <string.h>
  50 #include <sys/stat.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 #ifdef EDITLINE
  67 #ifdef __minix_vmd
  68 #include <readline/readline.h>
  69 #else
  70 /* What about other systems? */
  71 char *readline(char *prompt);
  72 #endif
  73 #else
  74 #include "myhistedit.h"
  75 #endif
  76 #include "redir.h"
  77 #include "trap.h"
  78
  79 static void popstring(void);
  80
  81 #define EOF_NLEFT -99           /* value of parsenleft when EOF pushed back */
  82
  83 MKINIT
  84 struct strpush {
  85         struct strpush *prev;   /* preceding string on stack */
  86         char *prevstring;
  87         int prevnleft;
  88         int prevlleft;
  89         struct alias *ap;       /* if push was associated with an alias */
  90 };
  91
  92 /*
  93  * The parsefile structure pointed to by the global variable parsefile
  94  * contains information about the current file being read.
  95  */
  96
  97 MKINIT
  98 struct parsefile {
  99         struct parsefile *prev; /* preceding file on stack */
 100         int linno;              /* current line */
 101         int fd;                 /* file descriptor (or -1 if string) */
 102         int nleft;              /* number of chars left in this line */
 103         int lleft;              /* number of lines left in this buffer */
 104         char *nextc;            /* next char in buffer */
 105         char *buf;              /* input buffer */
 106         struct strpush *strpush; /* for pushing strings at this level */
 107         struct strpush basestrpush; /* so pushing one is fast */
 108 };
 109
 110
 111 int plinno = 1;                 /* input line number */
 112 MKINIT int parsenleft;          /* copy of parsefile->nleft */
 113 MKINIT int parselleft;          /* copy of parsefile->lleft */
 114 char *parsenextc;               /* copy of parsefile->nextc */
 115 MKINIT struct parsefile basepf; /* top level input file */
 116 char basebuf[BUFSIZ];           /* buffer for top level input file */
 117 STATIC struct parsefile *parsefile = &basepf;   /* current input file */
 118 int init_editline = 0;          /* editline library initialized? */
 119 int whichprompt;                /* -1 == PSE, 1 == PS1, 2 == PS2 */
 120
 121 #ifndef EDITLINE
 122 EditLine *el;                   /* cookie for editline package */
 123 #endif
 124
 125 STATIC void pushfile(void);
 126 static int preadfd(void);
 127
 128 #ifdef mkinit
 129 INCLUDE "input.h"
 130 INCLUDE "error.h"
 131
 132 INIT {
 133         extern char basebuf[];
 134
 135         basepf.nextc = basepf.buf = basebuf;
 136 }
 137
 138 RESET {
 139         if (exception != EXSHELLPROC)
 140                 parselleft = parsenleft = 0;    /* clear input buffer */
 141         popallfiles();
 142 }
 143
 144 SHELLPROC {
 145         popallfiles();
 146 }
 147 #endif
 148
 149
 150 /*
 151  * Read a line from the script.
 152  */
 153
 154 char *
 155 pfgets(char *line, int len)
 156 {
 157         char *p = line;
 158         int nleft = len;
 159         int c;
 160
 161         while (--nleft > 0) {
 162                 c = pgetc_macro();
 163                 if (c == PEOF) {
 164                         if (p == line)
 165                                 return NULL;
 166                         break;
 167                 }
 168                 *p++ = c;
 169                 if (c == '\n')
 170                         break;
 171         }
 172         *p = '\0';
 173         return line;
 174 }
 175
 176
 177
 178 /*
 179  * Read a character from the script, returning PEOF on end of file.
 180  * Nul characters in the input are silently discarded.
 181  */
 182
 183 int
 184 pgetc(void)
 185 {
 186         return pgetc_macro();
 187 }
 188
 189
 190 static int
 191 preadfd(void)
 192 {
 193         int nr;
 194         parsenextc = parsefile->buf;
 195
 196 #if !defined(NO_HISTORY) && !defined(EDITLINE)
 197         if (el != NULL && gotwinch) {
 198                 gotwinch = 0;
 199                 el_resize(el);
 200         }
 201 #endif
 202 retry:
 203 #ifndef NO_HISTORY
 204 #ifdef EDITLINE
 205         if (parsefile->fd == 0 && editable) {
 206                 static const char *rl_cp= NULL;
 207                 static size_t rl_off= 0;
 208
 209                 if (!rl_cp)
 210                 {
 211                         rl_cp = readline(getprompt(NULL));
 212                         if (rl_cp == NULL)
 213                                 nr = 0;
 214                 }
 215                 if (rl_cp)
 216                 {
 217                         nr= strlen(rl_cp+rl_off);
 218                         if (nr >= BUFSIZ-1)
 219                         {
 220                                 nr= BUFSIZ-1;
 221                                 (void) memcpy(parsenextc, rl_cp+rl_off, nr);
 222                                 rl_off += nr;
 223                         }
 224                         else
 225                         {
 226                                 (void) memcpy(parsenextc, rl_cp+rl_off, nr);
 227                                 parsenextc[nr++]= '\n';
 228                                 free((void *)rl_cp);
 229                                 rl_cp= NULL;
 230                                 rl_off= 0;
 231                         }
 232                 }
 233         } else
 234 #else /* !EDITLINE */
 235         if (parsefile->fd == 0 && el) {
 236                 const char *rl_cp;
 237
 238                 rl_cp = el_gets(el, &nr);
 239                 if (rl_cp == NULL)
 240                         nr = 0;
 241                 else {
 242                         /* XXX - BUFSIZE should redesign so not necessary */
 243                         (void) strcpy(parsenextc, rl_cp);
 244                 }
 245         } else
 246 #endif /* !EDITLINE */
 247 #endif
 248                 nr = read(parsefile->fd, parsenextc, BUFSIZ - 1);
 249
 250         if (nr <= 0) {
 251                 if (nr < 0) {
 252                         if (errno == EINTR)
 253                                 goto retry;
 254 #ifdef EWOULDBLOCK
 255                         if (parsefile->fd == 0 && errno == EWOULDBLOCK) {
 256                                 int flags = fcntl(0, F_GETFL, 0);
 257                                 if (flags >= 0 && flags & O_NONBLOCK) {
 258                                         flags &=~ O_NONBLOCK;
 259                                         if (fcntl(0, F_SETFL, flags) >= 0) {
 260                                                 out2str("sh: turning off NDELAY mode\n");
 261                                                 goto retry;
 262                                         }
 263                                 }
 264                         }
 265 #endif /* EWOULDBLOCK */
 266                 }
 267                 nr = -1;
 268         }
 269         return nr;
 270 }
 271
 272 /*
 273  * Refill the input buffer and return the next input character:
 274  *
 275  * 1) If a string was pushed back on the input, pop it;
 276  * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
 277  *    from a string so we can't refill the buffer, return EOF.
 278  * 3) If there is more in this buffer, use it else call read to fill it.
 279  * 4) Process input up to the next newline, deleting nul characters.
 280  */
 281
 282 int
 283 preadbuffer(void)
 284 {
 285         char *p, *q;
 286         int more;
 287         int something;
 288         char savec;
 289
 290         if (parsefile->strpush) {
 291                 popstring();
 292                 if (--parsenleft >= 0)
 293                         return (*parsenextc++);
 294         }
 295         if (parsenleft == EOF_NLEFT || parsefile->buf == NULL)
 296                 return PEOF;
 297         flushout(&output);
 298         flushout(&errout);
 299
 300 again:
 301         if (parselleft <= 0) {
 302                 if ((parselleft = preadfd()) == -1) {
 303                         parselleft = parsenleft = EOF_NLEFT;
 304                         return PEOF;
 305                 }
 306         }
 307
 308         q = p = parsenextc;
 309
 310         /* delete nul characters */
 311         something = 0;
 312         for (more = 1; more;) {
 313                 switch (*p) {
 314                 case '\0':
 315                         p++;    /* Skip nul */
 316                         goto check;
 317
 318                 case '\t':
 319                 case ' ':
 320                         break;
 321
 322                 case '\n':
 323                         parsenleft = q - parsenextc;
 324                         more = 0; /* Stop processing here */
 325                         break;
 326
 327                 default:
 328                         something = 1;
 329                         break;
 330                 }
 331
 332                 *q++ = *p++;
 333 check:
 334                 if (--parselleft <= 0) {
 335                         parsenleft = q - parsenextc - 1;
 336                         if (parsenleft < 0)
 337                                 goto again;
 338                         *q = '\0';
 339                         more = 0;
 340                 }
 341         }
 342
 343         savec = *q;
 344         *q = '\0';
 345
 346 #if !defined(NO_HISTORY) && !defined(EDITLINE)
 347         if (parsefile->fd == 0 && hist && something) {
 348                 HistEvent he;
 349                 INTOFF;
 350                 history(hist, &he, whichprompt == 1 ? H_ENTER : H_ADD,
 351                     parsenextc);
 352                 INTON;
 353         }
 354 #endif
 355
 356         if (vflag) {
 357                 out2str(parsenextc);
 358                 flushout(out2);
 359         }
 360
 361         *q = savec;
 362
 363         return *parsenextc++;
 364 }
 365
 366 /*
 367  * Undo the last call to pgetc.  Only one character may be pushed back.
 368  * PEOF may be pushed back.
 369  */
 370
 371 void
 372 pungetc(void)
 373 {
 374         parsenleft++;
 375         parsenextc--;
 376 }
 377
 378 /*
 379  * Push a string back onto the input at this current parsefile level.
 380  * We handle aliases this way.
 381  */
 382 void
 383 pushstring(char *s, int len, void *ap)
 384 {
 385         struct strpush *sp;
 386
 387         INTOFF;
 388 /*dbgprintf("*** calling pushstring: %s, %d\n", s, len);*/
 389         if (parsefile->strpush) {
 390                 sp = ckmalloc(sizeof (struct strpush));
 391                 sp->prev = parsefile->strpush;
 392                 parsefile->strpush = sp;
 393         } else
 394                 sp = parsefile->strpush = &(parsefile->basestrpush);
 395         sp->prevstring = parsenextc;
 396         sp->prevnleft = parsenleft;
 397         sp->prevlleft = parselleft;
 398         sp->ap = (struct alias *)ap;
 399         if (ap)
 400                 ((struct alias *)ap)->flag |= ALIASINUSE;
 401         parsenextc = s;
 402         parsenleft = len;
 403         INTON;
 404 }
 405
 406 static void
 407 popstring(void)
 408 {
 409         struct strpush *sp = parsefile->strpush;
 410
 411         INTOFF;
 412         parsenextc = sp->prevstring;
 413         parsenleft = sp->prevnleft;
 414         parselleft = sp->prevlleft;
 415 /*dbgprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/
 416         if (sp->ap)
 417                 sp->ap->flag &= ~ALIASINUSE;
 418         parsefile->strpush = sp->prev;
 419         if (sp != &(parsefile->basestrpush))
 420                 ckfree(sp);
 421         INTON;
 422 }
 423
 424 /*
 425  * Set the input to take input from a file.  If push is set, push the
 426  * old input onto the stack first.
 427  */
 428
 429 void
 430 setinputfile(char *fname, int push)
 431 {
 432         int fd;
 433         int fd2;
 434         struct stat statbuf;
 435         int saved_errno;
 436
 437         INTOFF;
 438         if ((fd = open(fname, O_RDONLY)) < 0)
 439                 error("Can't open %s: %s", fname, strerror(errno));
 440         if (fstat(fd, &statbuf) < 0) {
 441                 saved_errno = errno;
 442                 close(fd);
 443                 error("Can't stat %s: %s", fname, strerror(saved_errno));
 444         }
 445         if (!S_ISREG(statbuf.st_mode)) {
 446                 close(fd);
 447                 error("Can't open %s: %s", fname, strerror(ENOEXEC));
 448         }
 449         if (fd < 10) {
 450                 fd2 = fcntl(fd, F_DUPFD, 10);
 451                 close(fd);
 452                 if (fd2 < 0)
 453                         error("Out of file descriptors");
 454                 fd = fd2;
 455         }
 456         setinputfd(fd, push);
 457         INTON;
 458 }
 459
 460
 461 /*
 462  * Like setinputfile, but takes an open file descriptor.  Call this with
 463  * interrupts off.
 464  */
 465
 466 void
 467 setinputfd(int fd, int push)
 468 {
 469         (void)fcntl(fd, F_SETFD, FD_CLOEXEC);
 470         if (push) {
 471                 pushfile();
 472                 parsefile->buf = ckmalloc(BUFSIZ);
 473         }
 474         if (parsefile->fd > 0)
 475                 close(parsefile->fd);
 476         parsefile->fd = fd;
 477         if (parsefile->buf == NULL)
 478                 parsefile->buf = ckmalloc(BUFSIZ);
 479         parselleft = parsenleft = 0;
 480         plinno = 1;
 481 }
 482
 483
 484 /*
 485  * Like setinputfile, but takes input from a string.
 486  */
 487
 488 void
 489 setinputstring(char *string, int push)
 490 {
 491         INTOFF;
 492         if (push)
 493                 pushfile();
 494         parsenextc = string;
 495         parselleft = parsenleft = strlen(string);
 496         parsefile->buf = NULL;
 497         plinno = 1;
 498         INTON;
 499 }
 500
 501
 502
 503 /*
 504  * To handle the "." command, a stack of input files is used.  Pushfile
 505  * adds a new entry to the stack and popfile restores the previous level.
 506  */
 507
 508 STATIC void
 509 pushfile(void)
 510 {
 511         struct parsefile *pf;
 512
 513         parsefile->nleft = parsenleft;
 514         parsefile->lleft = parselleft;
 515         parsefile->nextc = parsenextc;
 516         parsefile->linno = plinno;
 517         pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile));
 518         pf->prev = parsefile;
 519         pf->fd = -1;
 520         pf->strpush = NULL;
 521         pf->basestrpush.prev = NULL;
 522         parsefile = pf;
 523 }
 524
 525
 526 void
 527 popfile(void)
 528 {
 529         struct parsefile *pf = parsefile;
 530
 531         INTOFF;
 532         if (pf->fd >= 0)
 533                 close(pf->fd);
 534         if (pf->buf)
 535                 ckfree(pf->buf);
 536         while (pf->strpush)
 537                 popstring();
 538         parsefile = pf->prev;
 539         ckfree(pf);
 540         parsenleft = parsefile->nleft;
 541         parselleft = parsefile->lleft;
 542         parsenextc = parsefile->nextc;
 543         plinno = parsefile->linno;
 544         INTON;
 545 }
 546
 547
 548 /*
 549  * Return to top level.
 550  */
 551
 552 void
 553 popallfiles(void)
 554 {
 555         while (parsefile != &basepf)
 556                 popfile();
 557 }
 558
 559
 560
 561 /*
 562  * Close the file(s) that the shell is reading commands from.  Called
 563  * after a fork is done.
 564  */
 565
 566 void
 567 closescript(void)
 568 {
 569         popallfiles();
 570         if (parsefile->fd > 0) {
 571                 close(parsefile->fd);
 572                 parsefile->fd = 0;
 573         }
 574 }
 575
 576 /*
 577  * $PchId: input.c,v 1.7 2006/05/29 13:09:38 philip Exp $
 578  */