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input.c revision 1.27 
      1 /*	$NetBSD: input.c,v 1.27 1997/07/04 21:02:03 christos 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. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the University of
     21  *	California, Berkeley and its contributors.
     22  * 4. Neither the name of the University nor the names of its contributors
     23  *    may be used to endorse or promote products derived from this software
     24  *    without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36  * SUCH DAMAGE.
     37  */
     38 
     39 #include <sys/cdefs.h>
     40 #ifndef lint
     41 #if 0
     42 static char sccsid[] = "@(#)input.c	8.3 (Berkeley) 6/9/95";
     43 #else
     44 __RCSID("$NetBSD: input.c,v 1.27 1997/07/04 21:02:03 christos Exp $");
     45 #endif
     46 #endif /* not lint */
     47 
     48 #include <stdio.h>	/* defines BUFSIZ */
     49 #include <fcntl.h>
     50 #include <errno.h>
     51 #include <unistd.h>
     52 #include <stdlib.h>
     53 #include <string.h>
     54 
     55 /*
     56  * This file implements the input routines used by the parser.
     57  */
     58 
     59 #include "shell.h"
     60 #include "redir.h"
     61 #include "syntax.h"
     62 #include "input.h"
     63 #include "output.h"
     64 #include "options.h"
     65 #include "memalloc.h"
     66 #include "error.h"
     67 #include "alias.h"
     68 #include "parser.h"
     69 #include "myhistedit.h"
     70 
     71 #define EOF_NLEFT -99		/* value of parsenleft when EOF pushed back */
     72 
     73 MKINIT
     74 struct strpush {
     75 	struct strpush *prev;	/* preceding string on stack */
     76 	char *prevstring;
     77 	int prevnleft;
     78 	int prevlleft;
     79 	struct alias *ap;	/* if push was associated with an alias */
     80 };
     81 
     82 /*
     83  * The parsefile structure pointed to by the global variable parsefile
     84  * contains information about the current file being read.
     85  */
     86 
     87 MKINIT
     88 struct parsefile {
     89 	struct parsefile *prev;	/* preceding file on stack */
     90 	int linno;		/* current line */
     91 	int fd;			/* file descriptor (or -1 if string) */
     92 	int nleft;		/* number of chars left in this line */
     93 	int lleft;		/* number of chars left in this buffer */
     94 	char *nextc;		/* next char in buffer */
     95 	char *buf;		/* input buffer */
     96 	struct strpush *strpush; /* for pushing strings at this level */
     97 	struct strpush basestrpush; /* so pushing one is fast */
     98 };
     99 
    100 
    101 int plinno = 1;			/* input line number */
    102 MKINIT int parsenleft;		/* copy of parsefile->nleft */
    103 MKINIT int parselleft;		/* copy of parsefile->lleft */
    104 char *parsenextc;		/* copy of parsefile->nextc */
    105 MKINIT struct parsefile basepf;	/* top level input file */
    106 char basebuf[BUFSIZ];		/* buffer for top level input file */
    107 struct parsefile *parsefile = &basepf;	/* current input file */
    108 int init_editline = 0;		/* editline library initialized? */
    109 int whichprompt;		/* 1 == PS1, 2 == PS2 */
    110 
    111 EditLine *el;			/* cookie for editline package */
    112 
    113 STATIC void pushfile __P((void));
    114 static int preadfd __P((void));
    115 
    116 #ifdef mkinit
    117 INCLUDE "input.h"
    118 INCLUDE "error.h"
    119 
    120 INIT {
    121 	extern char basebuf[];
    122 
    123 	basepf.nextc = basepf.buf = basebuf;
    124 }
    125 
    126 RESET {
    127 	if (exception != EXSHELLPROC)
    128 		parselleft = parsenleft = 0;	/* clear input buffer */
    129 	popallfiles();
    130 }
    131 
    132 SHELLPROC {
    133 	popallfiles();
    134 }
    135 #endif
    136 
    137 
    138 /*
    139  * Read a line from the script.
    140  */
    141 
    142 char *
    143 pfgets(line, len)
    144 	char *line;
    145 	int len;
    146 {
    147 	char *p = line;
    148 	int nleft = len;
    149 	int c;
    150 
    151 	while (--nleft > 0) {
    152 		c = pgetc_macro();
    153 		if (c == PEOF) {
    154 			if (p == line)
    155 				return NULL;
    156 			break;
    157 		}
    158 		*p++ = c;
    159 		if (c == '\n')
    160 			break;
    161 	}
    162 	*p = '\0';
    163 	return line;
    164 }
    165 
    166 
    167 
    168 /*
    169  * Read a character from the script, returning PEOF on end of file.
    170  * Nul characters in the input are silently discarded.
    171  */
    172 
    173 int
    174 pgetc()
    175 {
    176 	return pgetc_macro();
    177 }
    178 
    179 
    180 static int
    181 preadfd()
    182 {
    183 	int nr;
    184 	parsenextc = parsefile->buf;
    185 
    186 retry:
    187 #ifndef SMALL
    188 	if (parsefile->fd == 0 && el) {
    189 		const char *rl_cp;
    190 
    191 		rl_cp = el_gets(el, &nr);
    192 		if (rl_cp == NULL)
    193 			nr = 0;
    194 		else {
    195 			/* XXX - BUFSIZE should redesign so not necessary */
    196 			(void) strcpy(parsenextc, rl_cp);
    197 		}
    198 	} else
    199 #endif
    200 		nr = read(parsefile->fd, parsenextc, BUFSIZ - 1);
    201 
    202 
    203 	if (nr <= 0) {
    204                 if (nr < 0) {
    205                         if (errno == EINTR)
    206                                 goto retry;
    207                         if (parsefile->fd == 0 && errno == EWOULDBLOCK) {
    208                                 int flags = fcntl(0, F_GETFL, 0);
    209                                 if (flags >= 0 && flags & O_NONBLOCK) {
    210                                         flags &=~ O_NONBLOCK;
    211                                         if (fcntl(0, F_SETFL, flags) >= 0) {
    212 						out2str("sh: turning off NDELAY mode\n");
    213                                                 goto retry;
    214                                         }
    215                                 }
    216                         }
    217                 }
    218                 nr = -1;
    219 	}
    220 	return nr;
    221 }
    222 
    223 /*
    224  * Refill the input buffer and return the next input character:
    225  *
    226  * 1) If a string was pushed back on the input, pop it;
    227  * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
    228  *    from a string so we can't refill the buffer, return EOF.
    229  * 3) If the is more stuff in this buffer, use it else call read to fill it.
    230  * 4) Process input up to the next newline, deleting nul characters.
    231  */
    232 
    233 int
    234 preadbuffer()
    235 {
    236 	char *p, *q;
    237 	int more;
    238 	int something;
    239 	extern EditLine *el;
    240 	char savec;
    241 
    242 	if (parsefile->strpush) {
    243 		popstring();
    244 		if (--parsenleft >= 0)
    245 			return (*parsenextc++);
    246 	}
    247 	if (parsenleft == EOF_NLEFT || parsefile->buf == NULL)
    248 		return PEOF;
    249 	flushout(&output);
    250 	flushout(&errout);
    251 
    252 again:
    253 	if (parselleft <= 0) {
    254 		if ((parselleft = preadfd()) == -1) {
    255 			parselleft = parsenleft = EOF_NLEFT;
    256 			return PEOF;
    257 		}
    258 	}
    259 
    260 	q = p = parsenextc;
    261 
    262 	/* delete nul characters */
    263 	something = 0;
    264 	for (more = 1; more;) {
    265 		switch (*p) {
    266 		case '\0':
    267 			p++;	/* Skip nul */
    268 			goto check;
    269 
    270 		case '\t':
    271 		case ' ':
    272 			break;
    273 
    274 		case '\n':
    275 			parsenleft = q - parsenextc;
    276 			more = 0; /* Stop processing here */
    277 			break;
    278 
    279 		default:
    280 			something = 1;
    281 			break;
    282 		}
    283 
    284 		*q++ = *p++;
    285 check:
    286 		if (--parselleft <= 0) {
    287 			parsenleft = q - parsenextc - 1;
    288 			if (parsenleft < 0)
    289 				goto again;
    290 			*q = '\0';
    291 			more = 0;
    292 		}
    293 	}
    294 
    295 	savec = *q;
    296 	*q = '\0';
    297 
    298 #ifndef SMALL
    299 	if (parsefile->fd == 0 && hist && something) {
    300 		INTOFF;
    301 		history(hist, whichprompt == 1 ? H_ENTER : H_ADD, parsenextc);
    302 		INTON;
    303 	}
    304 #endif
    305 
    306 	if (vflag) {
    307 		out2str(parsenextc);
    308 		flushout(out2);
    309 	}
    310 
    311 	*q = savec;
    312 
    313 	return *parsenextc++;
    314 }
    315 
    316 /*
    317  * Undo the last call to pgetc.  Only one character may be pushed back.
    318  * PEOF may be pushed back.
    319  */
    320 
    321 void
    322 pungetc() {
    323 	parsenleft++;
    324 	parsenextc--;
    325 }
    326 
    327 /*
    328  * Push a string back onto the input at this current parsefile level.
    329  * We handle aliases this way.
    330  */
    331 void
    332 pushstring(s, len, ap)
    333 	char *s;
    334 	int len;
    335 	void *ap;
    336 	{
    337 	struct strpush *sp;
    338 
    339 	INTOFF;
    340 /*dprintf("*** calling pushstring: %s, %d\n", s, len);*/
    341 	if (parsefile->strpush) {
    342 		sp = ckmalloc(sizeof (struct strpush));
    343 		sp->prev = parsefile->strpush;
    344 		parsefile->strpush = sp;
    345 	} else
    346 		sp = parsefile->strpush = &(parsefile->basestrpush);
    347 	sp->prevstring = parsenextc;
    348 	sp->prevnleft = parsenleft;
    349 	sp->prevlleft = parselleft;
    350 	sp->ap = (struct alias *)ap;
    351 	if (ap)
    352 		((struct alias *)ap)->flag |= ALIASINUSE;
    353 	parsenextc = s;
    354 	parsenleft = len;
    355 	INTON;
    356 }
    357 
    358 void
    359 popstring()
    360 {
    361 	struct strpush *sp = parsefile->strpush;
    362 
    363 	INTOFF;
    364 	parsenextc = sp->prevstring;
    365 	parsenleft = sp->prevnleft;
    366 	parselleft = sp->prevlleft;
    367 /*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/
    368 	if (sp->ap)
    369 		sp->ap->flag &= ~ALIASINUSE;
    370 	parsefile->strpush = sp->prev;
    371 	if (sp != &(parsefile->basestrpush))
    372 		ckfree(sp);
    373 	INTON;
    374 }
    375 
    376 /*
    377  * Set the input to take input from a file.  If push is set, push the
    378  * old input onto the stack first.
    379  */
    380 
    381 void
    382 setinputfile(fname, push)
    383 	char *fname;
    384 	int push;
    385 {
    386 	int fd;
    387 	int fd2;
    388 
    389 	INTOFF;
    390 	if ((fd = open(fname, O_RDONLY)) < 0)
    391 		error("Can't open %s", fname);
    392 	if (fd < 10) {
    393 		fd2 = copyfd(fd, 10);
    394 		close(fd);
    395 		if (fd2 < 0)
    396 			error("Out of file descriptors");
    397 		fd = fd2;
    398 	}
    399 	setinputfd(fd, push);
    400 	INTON;
    401 }
    402 
    403 
    404 /*
    405  * Like setinputfile, but takes an open file descriptor.  Call this with
    406  * interrupts off.
    407  */
    408 
    409 void
    410 setinputfd(fd, push)
    411 	int fd, push;
    412 {
    413 	(void) fcntl(fd, F_SETFD, FD_CLOEXEC);
    414 	if (push) {
    415 		pushfile();
    416 		parsefile->buf = ckmalloc(BUFSIZ);
    417 	}
    418 	if (parsefile->fd > 0)
    419 		close(parsefile->fd);
    420 	parsefile->fd = fd;
    421 	if (parsefile->buf == NULL)
    422 		parsefile->buf = ckmalloc(BUFSIZ);
    423 	parselleft = parsenleft = 0;
    424 	plinno = 1;
    425 }
    426 
    427 
    428 /*
    429  * Like setinputfile, but takes input from a string.
    430  */
    431 
    432 void
    433 setinputstring(string, push)
    434 	char *string;
    435 	int push;
    436 	{
    437 	INTOFF;
    438 	if (push)
    439 		pushfile();
    440 	parsenextc = string;
    441 	parselleft = parsenleft = strlen(string);
    442 	parsefile->buf = NULL;
    443 	plinno = 1;
    444 	INTON;
    445 }
    446 
    447 
    448 
    449 /*
    450  * To handle the "." command, a stack of input files is used.  Pushfile
    451  * adds a new entry to the stack and popfile restores the previous level.
    452  */
    453 
    454 STATIC void
    455 pushfile() {
    456 	struct parsefile *pf;
    457 
    458 	parsefile->nleft = parsenleft;
    459 	parsefile->lleft = parselleft;
    460 	parsefile->nextc = parsenextc;
    461 	parsefile->linno = plinno;
    462 	pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile));
    463 	pf->prev = parsefile;
    464 	pf->fd = -1;
    465 	pf->strpush = NULL;
    466 	pf->basestrpush.prev = NULL;
    467 	parsefile = pf;
    468 }
    469 
    470 
    471 void
    472 popfile() {
    473 	struct parsefile *pf = parsefile;
    474 
    475 	INTOFF;
    476 	if (pf->fd >= 0)
    477 		close(pf->fd);
    478 	if (pf->buf)
    479 		ckfree(pf->buf);
    480 	while (pf->strpush)
    481 		popstring();
    482 	parsefile = pf->prev;
    483 	ckfree(pf);
    484 	parsenleft = parsefile->nleft;
    485 	parselleft = parsefile->lleft;
    486 	parsenextc = parsefile->nextc;
    487 	plinno = parsefile->linno;
    488 	INTON;
    489 }
    490 
    491 
    492 /*
    493  * Return to top level.
    494  */
    495 
    496 void
    497 popallfiles() {
    498 	while (parsefile != &basepf)
    499 		popfile();
    500 }
    501 
    502 
    503 
    504 /*
    505  * Close the file(s) that the shell is reading commands from.  Called
    506  * after a fork is done.
    507  */
    508 
    509 void
    510 closescript() {
    511 	popallfiles();
    512 	if (parsefile->fd > 0) {
    513 		close(parsefile->fd);
    514 		parsefile->fd = 0;
    515 	}
    516 }
    517