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 /*
  39 #include <sys/cdefs.h>
  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
  51 /*
  52  * This file implements the input routines used by the parser.
  53  */
  54
  55 #include "shell.h"
  56 #include "redir.h"
  57 #include "syntax.h"
  58 #include "input.h"
  59 #include "output.h"
  60 #include "options.h"
  61 #include "memalloc.h"
  62 #include "error.h"
  63 #include "alias.h"
  64 #include "parser.h"
  65 #ifdef EDITLINE
  66 #ifdef __minix_vmd
  67 #include <readline/readline.h>
  68 #else
  69 /* What about other systems? */
  70 char *readline(char *prompt);
  71 #endif
  72 #else
  73 #include "myhistedit.h"
  74 #endif
  75 #include "redir.h"
  76 #include "trap.h"
  77
  78 static void popstring(void);
  79
  80 #define EOF_NLEFT -99           /* value of parsenleft when EOF pushed back */
  81
  82 MKINIT
  83 struct strpush {
  84         struct strpush *prev;   /* preceding string on stack */
  85         char *prevstring;
  86         int prevnleft;
  87         int prevlleft;
  88         struct alias *ap;       /* if push was associated with an alias */
  89 };
  90
  91 /*
  92  * The parsefile structure pointed to by the global variable parsefile
  93  * contains information about the current file being read.
  94  */
  95
  96 MKINIT
  97 struct parsefile {
  98         struct parsefile *prev; /* preceding file on stack */
  99         int linno;              /* current line */
 100         int fd;                 /* file descriptor (or -1 if string) */
 101         int nleft;              /* number of chars left in this line */
 102         int lleft;              /* number of lines left in this buffer */
 103         char *nextc;            /* next char in buffer */
 104         char *buf;              /* input buffer */
 105         struct strpush *strpush; /* for pushing strings at this level */
 106         struct strpush basestrpush; /* so pushing one is fast */
 107 };
 108
 109
 110 int plinno = 1;                 /* input line number */
 111 MKINIT int parsenleft;          /* copy of parsefile->nleft */
 112 MKINIT int parselleft;          /* copy of parsefile->lleft */
 113 char *parsenextc;               /* copy of parsefile->nextc */
 114 MKINIT struct parsefile basepf; /* top level input file */
 115 char basebuf[BUFSIZ];           /* buffer for top level input file */
 116 STATIC struct parsefile *parsefile = &basepf;   /* current input file */
 117 int init_editline = 0;          /* editline library initialized? */
 118 int whichprompt;                /* -1 == PSE, 1 == PS1, 2 == PS2 */
 119
 120 #ifndef EDITLINE
 121 EditLine *el;                   /* cookie for editline package */
 122 #endif
 123
 124 STATIC void pushfile(void);
 125 static int preadfd(void);
 126
 127 #ifdef mkinit
 128 INCLUDE "input.h"
 129 INCLUDE "error.h"
 130
 131 INIT {
 132         extern char basebuf[];
 133
 134         basepf.nextc = basepf.buf = basebuf;
 135 }
 136
 137 RESET {
 138         if (exception != EXSHELLPROC)
 139                 parselleft = parsenleft = 0;    /* clear input buffer */
 140         popallfiles();
 141 }
 142
 143 SHELLPROC {
 144         popallfiles();
 145 }
 146 #endif
 147
 148
 149 /*
 150  * Read a line from the script.
 151  */
 152
 153 char *
 154 pfgets(char *line, int len)
 155 {
 156         char *p = line;
 157         int nleft = len;
 158         int c;
 159
 160         while (--nleft > 0) {
 161                 c = pgetc_macro();
 162                 if (c == PEOF) {
 163                         if (p == line)
 164                                 return NULL;
 165                         break;
 166                 }
 167                 *p++ = c;
 168                 if (c == '\n')
 169                         break;
 170         }
 171         *p = '\0';
 172         return line;
 173 }
 174
 175
 176
 177 /*
 178  * Read a character from the script, returning PEOF on end of file.
 179  * Nul characters in the input are silently discarded.
 180  */
 181
 182 int
 183 pgetc(void)
 184 {
 185         return pgetc_macro();
 186 }
 187
 188
 189 static int
 190 preadfd(void)
 191 {
 192         int nr;
 193         parsenextc = parsefile->buf;
 194
 195 #if !defined(NO_HISTORY) && !defined(EDITLINE)
 196         if (el != NULL && gotwinch) {
 197                 gotwinch = 0;
 198                 el_resize(el);
 199         }
 200 #endif
 201 retry:
 202 #ifndef NO_HISTORY
 203 #ifdef EDITLINE
 204         if (parsefile->fd == 0 && editable) {
 205                 static const char *rl_cp= NULL;
 206                 static size_t rl_off= 0;
 207
 208                 if (!rl_cp)
 209                 {
 210                         rl_cp = readline(getprompt(NULL));
 211                         if (rl_cp == NULL)
 212                                 nr = 0;
 213                 }
 214                 if (rl_cp)
 215                 {
 216                         nr= strlen(rl_cp+rl_off);
 217                         if (nr >= BUFSIZ-1)
 218                         {
 219                                 nr= BUFSIZ-1;
 220                                 (void) memcpy(parsenextc, rl_cp+rl_off, nr);
 221                                 rl_off += nr;
 222                         }
 223                         else
 224                         {
 225                                 (void) memcpy(parsenextc, rl_cp+rl_off, nr);
 226                                 parsenextc[nr++]= '\n';
 227                                 free(rl_cp);
 228                                 rl_cp= NULL;
 229                                 rl_off= 0;
 230                         }
 231                 }
 232         } else
 233 #else /* !EDITLINE */
 234         if (parsefile->fd == 0 && el) {
 235                 const char *rl_cp;
 236
 237                 rl_cp = el_gets(el, &nr);
 238                 if (rl_cp == NULL)
 239                         nr = 0;
 240                 else {
 241                         /* XXX - BUFSIZE should redesign so not necessary */
 242                         (void) strcpy(parsenextc, rl_cp);
 243                 }
 244         } else
 245 #endif /* !EDITLINE */
 246 #endif
 247                 nr = read(parsefile->fd, parsenextc, BUFSIZ - 1);
 248
 249         if (nr <= 0) {
 250                 if (nr < 0) {
 251                         if (errno == EINTR)
 252                                 goto retry;
 253 #ifdef EWOULDBLOCK
 254                         if (parsefile->fd == 0 && errno == EWOULDBLOCK) {
 255                                 int flags = fcntl(0, F_GETFL, 0);
 256                                 if (flags >= 0 && flags & O_NONBLOCK) {
 257                                         flags &=~ O_NONBLOCK;
 258                                         if (fcntl(0, F_SETFL, flags) >= 0) {
 259                                                 out2str("sh: turning off NDELAY mode\n");
 260                                                 goto retry;
 261                                         }
 262                                 }
 263                         }
 264 #endif /* EWOULDBLOCK */
 265                 }
 266                 nr = -1;
 267         }
 268         return nr;
 269 }
 270
 271 /*
 272  * Refill the input buffer and return the next input character:
 273  *
 274  * 1) If a string was pushed back on the input, pop it;
 275  * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
 276  *    from a string so we can't refill the buffer, return EOF.
 277  * 3) If there is more in this buffer, use it else call read to fill it.
 278  * 4) Process input up to the next newline, deleting nul characters.
 279  */
 280
 281 int
 282 preadbuffer(void)
 283 {
 284         char *p, *q;
 285         int more;
 286         int something;
 287         char savec;
 288
 289         if (parsefile->strpush) {
 290                 popstring();
 291                 if (--parsenleft >= 0)
 292                         return (*parsenextc++);
 293         }
 294         if (parsenleft == EOF_NLEFT || parsefile->buf == NULL)
 295                 return PEOF;
 296         flushout(&output);
 297         flushout(&errout);
 298
 299 again:
 300         if (parselleft <= 0) {
 301                 if ((parselleft = preadfd()) == -1) {
 302                         parselleft = parsenleft = EOF_NLEFT;
 303                         return PEOF;
 304                 }
 305         }
 306
 307         q = p = parsenextc;
 308
 309         /* delete nul characters */
 310         something = 0;
 311         for (more = 1; more;) {
 312                 switch (*p) {
 313                 case '\0':
 314                         p++;    /* Skip nul */
 315                         goto check;
 316
 317                 case '\t':
 318                 case ' ':
 319                         break;
 320
 321                 case '\n':
 322                         parsenleft = q - parsenextc;
 323                         more = 0; /* Stop processing here */
 324                         break;
 325
 326                 default:
 327                         something = 1;
 328                         break;
 329                 }
 330
 331                 *q++ = *p++;
 332 check:
 333                 if (--parselleft <= 0) {
 334                         parsenleft = q - parsenextc - 1;
 335                         if (parsenleft < 0)
 336                                 goto again;
 337                         *q = '\0';
 338                         more = 0;
 339                 }
 340         }
 341
 342         savec = *q;
 343         *q = '\0';
 344
 345 #if !defined(NO_HISTORY) && !defined(EDITLINE)
 346         if (parsefile->fd == 0 && hist && something) {
 347                 HistEvent he;
 348                 INTOFF;
 349                 history(hist, &he, whichprompt == 1 ? H_ENTER : H_ADD,
 350                     parsenextc);
 351                 INTON;
 352         }
 353 #endif
 354
 355         if (vflag) {
 356                 out2str(parsenextc);
 357                 flushout(out2);
 358         }
 359
 360         *q = savec;
 361
 362         return *parsenextc++;
 363 }
 364
 365 /*
 366  * Undo the last call to pgetc.  Only one character may be pushed back.
 367  * PEOF may be pushed back.
 368  */
 369
 370 void
 371 pungetc(void)
 372 {
 373         parsenleft++;
 374         parsenextc--;
 375 }
 376
 377 /*
 378  * Push a string back onto the input at this current parsefile level.
 379  * We handle aliases this way.
 380  */
 381 void
 382 pushstring(char *s, int len, void *ap)
 383 {
 384         struct strpush *sp;
 385
 386         INTOFF;
 387 /*dprintf("*** calling pushstring: %s, %d\n", s, len);*/
 388         if (parsefile->strpush) {
 389                 sp = ckmalloc(sizeof (struct strpush));
 390                 sp->prev = parsefile->strpush;
 391                 parsefile->strpush = sp;
 392         } else
 393                 sp = parsefile->strpush = &(parsefile->basestrpush);
 394         sp->prevstring = parsenextc;
 395         sp->prevnleft = parsenleft;
 396         sp->prevlleft = parselleft;
 397         sp->ap = (struct alias *)ap;
 398         if (ap)
 399                 ((struct alias *)ap)->flag |= ALIASINUSE;
 400         parsenextc = s;
 401         parsenleft = len;
 402         INTON;
 403 }
 404
 405 static void
 406 popstring(void)
 407 {
 408         struct strpush *sp = parsefile->strpush;
 409
 410         INTOFF;
 411         parsenextc = sp->prevstring;
 412         parsenleft = sp->prevnleft;
 413         parselleft = sp->prevlleft;
 414 /*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/
 415         if (sp->ap)
 416                 sp->ap->flag &= ~ALIASINUSE;
 417         parsefile->strpush = sp->prev;
 418         if (sp != &(parsefile->basestrpush))
 419                 ckfree(sp);
 420         INTON;
 421 }
 422
 423 /*
 424  * Set the input to take input from a file.  If push is set, push the
 425  * old input onto the stack first.
 426  */
 427
 428 void
 429 setinputfile(char *fname, int push)
 430 {
 431         int fd;
 432         int fd2;
 433
 434         INTOFF;
 435         if ((fd = open(fname, O_RDONLY)) < 0)
 436                 error("Can't open %s: %s", fname, strerror(errno));
 437         if (fd < 10) {
 438                 fd2 = fcntl(fd, F_DUPFD, 10);
 439                 close(fd);
 440                 if (fd2 < 0)
 441                         error("Out of file descriptors");
 442                 fd = fd2;
 443         }
 444         setinputfd(fd, push);
 445         INTON;
 446 }
 447
 448
 449 /*
 450  * Like setinputfile, but takes an open file descriptor.  Call this with
 451  * interrupts off.
 452  */
 453
 454 void
 455 setinputfd(int fd, int push)
 456 {
 457         (void)fcntl(fd, F_SETFD, FD_CLOEXEC);
 458         if (push) {
 459                 pushfile();
 460                 parsefile->buf = ckmalloc(BUFSIZ);
 461         }
 462         if (parsefile->fd > 0)
 463                 close(parsefile->fd);
 464         parsefile->fd = fd;
 465         if (parsefile->buf == NULL)
 466                 parsefile->buf = ckmalloc(BUFSIZ);
 467         parselleft = parsenleft = 0;
 468         plinno = 1;
 469 }
 470
 471
 472 /*
 473  * Like setinputfile, but takes input from a string.
 474  */
 475
 476 void
 477 setinputstring(char *string, int push)
 478 {
 479         INTOFF;
 480         if (push)
 481                 pushfile();
 482         parsenextc = string;
 483         parselleft = parsenleft = strlen(string);
 484         parsefile->buf = NULL;
 485         plinno = 1;
 486         INTON;
 487 }
 488
 489
 490
 491 /*
 492  * To handle the "." command, a stack of input files is used.  Pushfile
 493  * adds a new entry to the stack and popfile restores the previous level.
 494  */
 495
 496 STATIC void
 497 pushfile(void)
 498 {
 499         struct parsefile *pf;
 500
 501         parsefile->nleft = parsenleft;
 502         parsefile->lleft = parselleft;
 503         parsefile->nextc = parsenextc;
 504         parsefile->linno = plinno;
 505         pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile));
 506         pf->prev = parsefile;
 507         pf->fd = -1;
 508         pf->strpush = NULL;
 509         pf->basestrpush.prev = NULL;
 510         parsefile = pf;
 511 }
 512
 513
 514 void
 515 popfile(void)
 516 {
 517         struct parsefile *pf = parsefile;
 518
 519         INTOFF;
 520         if (pf->fd >= 0)
 521                 close(pf->fd);
 522         if (pf->buf)
 523                 ckfree(pf->buf);
 524         while (pf->strpush)
 525                 popstring();
 526         parsefile = pf->prev;
 527         ckfree(pf);
 528         parsenleft = parsefile->nleft;
 529         parselleft = parsefile->lleft;
 530         parsenextc = parsefile->nextc;
 531         plinno = parsefile->linno;
 532         INTON;
 533 }
 534
 535
 536 /*
 537  * Return to top level.
 538  */
 539
 540 void
 541 popallfiles(void)
 542 {
 543         while (parsefile != &basepf)
 544                 popfile();
 545 }
 546
 547
 548
 549 /*
 550  * Close the file(s) that the shell is reading commands from.  Called
 551  * after a fork is done.
 552  */
 553
 554 void
 555 closescript(void)
 556 {
 557         popallfiles();
 558         if (parsefile->fd > 0) {
 559                 close(parsefile->fd);
 560                 parsefile->fd = 0;
 561         }
 562 }
 563
 564 /*
 565  * $PchId: input.c,v 1.7 2006/05/29 13:09:38 philip Exp $
 566  */