src/kash/input.c

   1 /*      $NetBSD: input.c,v 1.39 2003/08/07 09:05:32 agc 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. Neither the name of the University nor the names of its contributors
  19  *    may be used to endorse or promote products derived from this software
  20  *    without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  */
  34
  35 #if 0
  36 #ifndef lint
  37 static char sccsid[] = "@(#)input.c     8.3 (Berkeley) 6/9/95";
  38 #else
  39 __RCSID("$NetBSD: input.c,v 1.39 2003/08/07 09:05:32 agc Exp $");
  40 #endif /* not lint */
  41 #endif
  42
  43 #include <stdio.h>      /* defines BUFSIZ */
  44 #include <errno.h>
  45 #include <stdlib.h>
  46 #include <string.h>
  47
  48 /*
  49  * This file implements the input routines used by the parser.
  50  */
  51
  52 #include "shell.h"
  53 #include "redir.h"
  54 #include "syntax.h"
  55 #include "input.h"
  56 #include "output.h"
  57 #include "options.h"
  58 #include "memalloc.h"
  59 #include "error.h"
  60 #include "alias.h"
  61 #include "parser.h"
  62 #include "myhistedit.h"
  63 #include "shinstance.h"
  64
  65 #define EOF_NLEFT -99           /* value of parsenleft when EOF pushed back */
  66
  67 //MKINIT
  68 //struct strpush {
  69 //      struct strpush *prev;   /* preceding string on stack */
  70 //      char *prevstring;
  71 //      int prevnleft;
  72 //      int prevlleft;
  73 //      struct alias *ap;       /* if push was associated with an alias */
  74 //};
  75 //
  76 ///*
  77 // * The parsefile structure pointed to by the global variable parsefile
  78 // * contains information about the current file being read.
  79 // */
  80 //
  81 //MKINIT
  82 //struct parsefile {
  83 //      struct parsefile *prev; /* preceding file on stack */
  84 //      int linno;              /* current line */
  85 //      int fd;                 /* file descriptor (or -1 if string) */
  86 //      int nleft;              /* number of chars left in this line */
  87 //      int lleft;              /* number of chars left in this buffer */
  88 //      char *nextc;            /* next char in buffer */
  89 //      char *buf;              /* input buffer */
  90 //      struct strpush *strpush; /* for pushing strings at this level */
  91 //      struct strpush basestrpush; /* so pushing one is fast */
  92 //};
  93 //
  94 //
  95 //int plinno = 1;                       /* input line number */
  96 //int parsenleft;                       /* copy of parsefile->nleft */
  97 //MKINIT int parselleft;                /* copy of parsefile->lleft */
  98 //char *parsenextc;             /* copy of parsefile->nextc */
  99 //MKINIT struct parsefile basepf;       /* top level input file */
 100 //MKINIT char basebuf[BUFSIZ];  /* buffer for top level input file */
 101 //struct parsefile *parsefile = &basepf;        /* current input file */
 102 //int init_editline = 0;                /* editline library initialized? */
 103 //int whichprompt;              /* 1 == PS1, 2 == PS2 */
 104 //
 105 //#ifndef SMALL
 106 //EditLine *el;                 /* cookie for editline package */
 107 //#endif
 108
 109 STATIC void pushfile(shinstance *psh);
 110 static int preadfd(shinstance *psh);
 111
 112 #ifdef mkinit
 113 INCLUDE <stdio.h>
 114 INCLUDE "input.h"
 115 INCLUDE "error.h"
 116
 117 INIT {
 118         psh->basepf.nextc = psh->basepf.buf = psh->basebuf;
 119 }
 120
 121 RESET {
 122         if (psh->exception != EXSHELLPROC)
 123                 psh->parselleft = psh->parsenleft = 0;  /* clear input buffer */
 124         popallfiles(psh);
 125 }
 126
 127 SHELLPROC {
 128         popallfiles(psh);
 129 }
 130 #endif
 131
 132
 133 /*
 134  * Read a line from the script.
 135  */
 136
 137 char *
 138 pfgets(shinstance *psh, char *line, int len)
 139 {
 140         char *p = line;
 141         int nleft = len;
 142         int c;
 143
 144         while (--nleft > 0) {
 145                 c = pgetc_macro(psh);
 146                 if (c == PEOF) {
 147                         if (p == line)
 148                                 return NULL;
 149                         break;
 150                 }
 151                 *p++ = c;
 152                 if (c == '\n')
 153                         break;
 154         }
 155         *p = '\0';
 156         return line;
 157 }
 158
 159
 160
 161 /*
 162  * Read a character from the script, returning PEOF on end of file.
 163  * Nul characters in the input are silently discarded.
 164  */
 165
 166 int
 167 pgetc(shinstance *psh)
 168 {
 169         return pgetc_macro(psh);
 170 }
 171
 172
 173 static int
 174 preadfd(shinstance *psh)
 175 {
 176         int nr;
 177         char *buf = psh->parsefile->buf;
 178         psh->parsenextc = buf;
 179
 180 retry:
 181 #ifndef SMALL
 182         if (psh->parsefile->fd == 0 && psh->el) {
 183                 static const char *rl_cp;
 184                 static int el_len;
 185
 186                 if (rl_cp == NULL)
 187                         rl_cp = el_gets(psh->el, &el_len);
 188                 if (rl_cp == NULL)
 189                         nr = 0;
 190                 else {
 191                         nr = el_len;
 192                         if (nr > BUFSIZ - 8)
 193                                 nr = BUFSIZ - 8;
 194                         memcpy(buf, rl_cp, nr);
 195                         if (nr != el_len) {
 196                                 el_len -= nr;
 197                                 rl_cp += nr;
 198                         } else
 199                                 rl_cp = 0;
 200                 }
 201
 202         } else
 203 #endif
 204                 nr = shfile_read(&psh->fdtab, psh->parsefile->fd, buf, BUFSIZ - 8);
 205
 206
 207         if (nr <= 0) {
 208                 if (nr < 0) {
 209                         if (errno == EINTR)
 210                                 goto retry;
 211                         if (psh->parsefile->fd == 0 && errno == EWOULDBLOCK) {
 212                                 int flags = shfile_fcntl(&psh->fdtab, 0, F_GETFL, 0);
 213                                 if (flags >= 0 && flags & O_NONBLOCK) {
 214                                         flags &=~ O_NONBLOCK;
 215                                         if (shfile_fcntl(&psh->fdtab, 0, F_SETFL, flags) >= 0) {
 216                                                 out2str(psh, "sh: turning off NDELAY mode\n");
 217                                                 goto retry;
 218                                         }
 219                                 }
 220                         }
 221                 }
 222                 nr = -1;
 223         }
 224         return nr;
 225 }
 226
 227 /*
 228  * Refill the input buffer and return the next input character:
 229  *
 230  * 1) If a string was pushed back on the input, pop it;
 231  * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
 232  *    from a string so we can't refill the buffer, return EOF.
 233  * 3) If the is more stuff in this buffer, use it else call read to fill it.
 234  * 4) Process input up to the next newline, deleting nul characters.
 235  */
 236
 237 int
 238 preadbuffer(shinstance *psh)
 239 {
 240         char *p, *q;
 241         int more;
 242         int something;
 243         char savec;
 244
 245         if (psh->parsefile->strpush) {
 246                 popstring(psh);
 247                 if (--psh->parsenleft >= 0)
 248                         return (*psh->parsenextc++);
 249         }
 250         if (psh->parsenleft == EOF_NLEFT || psh->parsefile->buf == NULL)
 251                 return PEOF;
 252         flushout(&psh->output);
 253         flushout(&psh->errout);
 254
 255 again:
 256         if (psh->parselleft <= 0) {
 257                 if ((psh->parselleft = preadfd(psh)) == -1) {
 258                         psh->parselleft = psh->parsenleft = EOF_NLEFT;
 259                         return PEOF;
 260                 }
 261         }
 262
 263         q = p = psh->parsenextc;
 264
 265         /* delete nul characters */
 266         something = 0;
 267         for (more = 1; more;) {
 268                 switch (*p) {
 269                 case '\0':
 270                         p++;    /* Skip nul */
 271                         goto check;
 272
 273                 case '\t':
 274                 case ' ':
 275                         break;
 276
 277                 case '\n':
 278                         psh->parsenleft = (int)(q - psh->parsenextc);
 279                         more = 0; /* Stop processing here */
 280                         break;
 281
 282                 default:
 283                         something = 1;
 284                         break;
 285                 }
 286
 287                 *q++ = *p++;
 288 check:
 289                 if (--psh->parselleft <= 0) {
 290                         psh->parsenleft = (int)(q - psh->parsenextc - 1);
 291                         if (psh->parsenleft < 0)
 292                                 goto again;
 293                         *q = '\0';
 294                         more = 0;
 295                 }
 296         }
 297
 298         savec = *q;
 299         *q = '\0';
 300
 301 #ifndef SMALL
 302         if (psh->parsefile->fd == 0 && hist && something) {
 303                 HistEvent he;
 304                 INTOFF;
 305                 history(hist, &he, psh->whichprompt == 1? H_ENTER : H_APPEND,
 306                     psh->parsenextc);
 307                 INTON;
 308         }
 309 #endif
 310
 311         if (vflag(psh)) {
 312                 out2str(psh, psh->parsenextc);
 313                 flushout(psh->out2);
 314         }
 315
 316         *q = savec;
 317
 318         return *psh->parsenextc++;
 319 }
 320
 321 /*
 322  * Undo the last call to pgetc.  Only one character may be pushed back.
 323  * PEOF may be pushed back.
 324  */
 325
 326 void
 327 pungetc(shinstance *psh)
 328 {
 329         psh->parsenleft++;
 330         psh->parsenextc--;
 331 }
 332
 333 /*
 334  * Push a string back onto the input at this current parsefile level.
 335  * We handle aliases this way.
 336  */
 337 void
 338 pushstring(shinstance *psh, char *s, size_t len, void *ap)
 339 {
 340         struct strpush *sp;
 341
 342         INTOFF;
 343 /*dprintf("*** calling pushstring: %s, %d\n", s, len);*/
 344         if (psh->parsefile->strpush) {
 345                 sp = ckmalloc(sizeof (struct strpush));
 346                 sp->prev = psh->parsefile->strpush;
 347                 psh->parsefile->strpush = sp;
 348         } else
 349                 sp = psh->parsefile->strpush = &(psh->parsefile->basestrpush);
 350         sp->prevstring = psh->parsenextc;
 351         sp->prevnleft = psh->parsenleft;
 352         sp->prevlleft = psh->parselleft;
 353         sp->ap = (struct alias *)ap;
 354         if (ap)
 355                 ((struct alias *)ap)->flag |= ALIASINUSE;
 356         psh->parsenextc = s;
 357         psh->parsenleft = (int)len;
 358         INTON;
 359 }
 360
 361 void
 362 popstring(shinstance *psh)
 363 {
 364         struct strpush *sp = psh->parsefile->strpush;
 365
 366         INTOFF;
 367         psh->parsenextc = sp->prevstring;
 368         psh->parsenleft = sp->prevnleft;
 369         psh->parselleft = sp->prevlleft;
 370 /*dprintf("*** calling popstring: restoring to '%s'\n", psh->parsenextc);*/
 371         if (sp->ap)
 372                 sp->ap->flag &= ~ALIASINUSE;
 373         psh->parsefile->strpush = sp->prev;
 374         if (sp != &(psh->parsefile->basestrpush))
 375                 ckfree(sp);
 376         INTON;
 377 }
 378
 379 /*
 380  * Set the input to take input from a file.  If push is set, push the
 381  * old input onto the stack first.
 382  */
 383
 384 void
 385 setinputfile(shinstance *psh, const char *fname, int push)
 386 {
 387         int fd;
 388         int fd2;
 389
 390         INTOFF;
 391 /** @todo shfile fixme */
 392         if ((fd = shfile_open(&psh->fdtab, fname, O_RDONLY, 0)) < 0)
 393                 error(psh, "Can't open %s", fname);
 394         if (fd < 10) {
 395                 fd2 = copyfd(psh, fd, 10);
 396                 shfile_close(&psh->fdtab, fd);
 397                 if (fd2 < 0)
 398                         error(psh, "Out of file descriptors");
 399                 fd = fd2;
 400         }
 401         setinputfd(psh, fd, push);
 402         INTON;
 403 }
 404
 405
 406 /*
 407  * Like setinputfile, but takes an open file descriptor.  Call this with
 408  * interrupts off.
 409  */
 410
 411 void
 412 setinputfd(shinstance *psh, int fd, int push)
 413 {
 414         (void) shfile_fcntl(&psh->fdtab, fd, F_SETFD, FD_CLOEXEC);
 415         if (push) {
 416                 pushfile(psh);
 417                 psh->parsefile->buf = ckmalloc(BUFSIZ);
 418         }
 419         if (psh->parsefile->fd > 0)
 420                 shfile_close(&psh->fdtab, psh->parsefile->fd);
 421         psh->parsefile->fd = fd;
 422         if (psh->parsefile->buf == NULL)
 423                 psh->parsefile->buf = ckmalloc(BUFSIZ);
 424         psh->parselleft = psh->parsenleft = 0;
 425         psh->plinno = 1;
 426 }
 427
 428
 429 /*
 430  * Like setinputfile, but takes input from a string.
 431  */
 432
 433 void
 434 setinputstring(shinstance *psh, char *string, int push)
 435 {
 436         INTOFF;
 437         if (push)
 438                 pushfile(psh);
 439         psh->parsenextc = string;
 440         psh->parselleft = psh->parsenleft = (int)strlen(string);
 441         psh->parsefile->buf = NULL;
 442         psh->plinno = 1;
 443         INTON;
 444 }
 445
 446
 447
 448 /*
 449  * To handle the "." command, a stack of input files is used.  Pushfile
 450  * adds a new entry to the stack and popfile restores the previous level.
 451  */
 452
 453 STATIC void
 454 pushfile(shinstance *psh)
 455 {
 456         struct parsefile *pf;
 457
 458         psh->parsefile->nleft = psh->parsenleft;
 459         psh->parsefile->lleft = psh->parselleft;
 460         psh->parsefile->nextc = psh->parsenextc;
 461         psh->parsefile->linno = psh->plinno;
 462         pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile));
 463         pf->prev = psh->parsefile;
 464         pf->fd = -1;
 465         pf->strpush = NULL;
 466         pf->basestrpush.prev = NULL;
 467         psh->parsefile = pf;
 468 }
 469
 470
 471 void
 472 popfile(shinstance *psh)
 473 {
 474         struct parsefile *pf = psh->parsefile;
 475
 476         INTOFF;
 477         if (pf->fd >= 0)
 478                 shfile_close(&psh->fdtab, pf->fd);
 479         if (pf->buf)
 480                 ckfree(pf->buf);
 481         while (pf->strpush)
 482                 popstring(psh);
 483         psh->parsefile = pf->prev;
 484         ckfree(pf);
 485         psh->parsenleft = psh->parsefile->nleft;
 486         psh->parselleft = psh->parsefile->lleft;
 487         psh->parsenextc = psh->parsefile->nextc;
 488         psh->plinno = psh->parsefile->linno;
 489         INTON;
 490 }
 491
 492
 493 /*
 494  * Return to top level.
 495  */
 496
 497 void
 498 popallfiles(shinstance *psh)
 499 {
 500         while (psh->parsefile != &psh->basepf)
 501                 popfile(psh);
 502 }
 503
 504
 505
 506 /*
 507  * Close the file(s) that the shell is reading commands from.  Called
 508  * after a fork is done.
 509  *
 510  * Takes one arg, vfork, which tells it to not modify its global vars
 511  * as it is still running in the parent.
 512  *
 513  * This code is (probably) unnecessary as the 'close on exec' flag is
 514  * set and should be enough.  In the vfork case it is definitely wrong
 515  * to close the fds as another fork() may be done later to feed data
 516  * from a 'here' document into a pipe and we don't want to close the
 517  * pipe!
 518  */
 519
 520 void
 521 closescript(shinstance *psh, int vforked)
 522 {
 523         if (vforked)
 524                 return;
 525         popallfiles(psh);
 526         if (psh->parsefile->fd > 0) {
 527                 shfile_close(&psh->fdtab, psh->parsefile->fd);
 528                 psh->parsefile->fd = 0;
 529         }
 530 }