Home | History | Annotate | Line # | Download | only in sh
input.c revision 1.34 
      1 /*	$NetBSD: input.c,v 1.34 2000/05/22 10:18:47 elric 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 1.34 2000/05/22 10:18:47 elric 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 	char *buf =  parsefile->buf;
    185 	parsenextc = buf;
    186 
    187 retry:
    188 #ifndef SMALL
    189 	if (parsefile->fd == 0 && el) {
    190 		const char *rl_cp;
    191 
    192 		rl_cp = el_gets(el, &nr);
    193 		if (rl_cp == NULL)
    194 			nr = 0;
    195 		else {
    196 			/* XXX - BUFSIZE should redesign so not necessary */
    197 			(void) strcpy(buf, rl_cp);
    198 		}
    199 	} else
    200 #endif
    201 		nr = read(parsefile->fd, buf, BUFSIZ - 1);
    202 
    203 
    204 	if (nr <= 0) {
    205                 if (nr < 0) {
    206                         if (errno == EINTR)
    207                                 goto retry;
    208                         if (parsefile->fd == 0 && errno == EWOULDBLOCK) {
    209                                 int flags = fcntl(0, F_GETFL, 0);
    210                                 if (flags >= 0 && flags & O_NONBLOCK) {
    211                                         flags &=~ O_NONBLOCK;
    212                                         if (fcntl(0, F_SETFL, flags) >= 0) {
    213 						out2str("sh: turning off NDELAY mode\n");
    214                                                 goto retry;
    215                                         }
    216                                 }
    217                         }
    218                 }
    219                 nr = -1;
    220 	}
    221 	return nr;
    222 }
    223 
    224 /*
    225  * Refill the input buffer and return the next input character:
    226  *
    227  * 1) If a string was pushed back on the input, pop it;
    228  * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
    229  *    from a string so we can't refill the buffer, return EOF.
    230  * 3) If the is more stuff in this buffer, use it else call read to fill it.
    231  * 4) Process input up to the next newline, deleting nul characters.
    232  */
    233 
    234 int
    235 preadbuffer()
    236 {
    237 	char *p, *q;
    238 	int more;
    239 	int something;
    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 		HistEvent he;
    301 		INTOFF;
    302 		history(hist, &he, whichprompt == 1? H_ENTER : H_APPEND,
    303 		    parsenextc);
    304 		INTON;
    305 	}
    306 #endif
    307 
    308 	if (vflag) {
    309 		out2str(parsenextc);
    310 		flushout(out2);
    311 	}
    312 
    313 	*q = savec;
    314 
    315 	return *parsenextc++;
    316 }
    317 
    318 /*
    319  * Undo the last call to pgetc.  Only one character may be pushed back.
    320  * PEOF may be pushed back.
    321  */
    322 
    323 void
    324 pungetc() {
    325 	parsenleft++;
    326 	parsenextc--;
    327 }
    328 
    329 /*
    330  * Push a string back onto the input at this current parsefile level.
    331  * We handle aliases this way.
    332  */
    333 void
    334 pushstring(s, len, ap)
    335 	char *s;
    336 	int len;
    337 	void *ap;
    338 	{
    339 	struct strpush *sp;
    340 
    341 	INTOFF;
    342 /*dprintf("*** calling pushstring: %s, %d\n", s, len);*/
    343 	if (parsefile->strpush) {
    344 		sp = ckmalloc(sizeof (struct strpush));
    345 		sp->prev = parsefile->strpush;
    346 		parsefile->strpush = sp;
    347 	} else
    348 		sp = parsefile->strpush = &(parsefile->basestrpush);
    349 	sp->prevstring = parsenextc;
    350 	sp->prevnleft = parsenleft;
    351 	sp->prevlleft = parselleft;
    352 	sp->ap = (struct alias *)ap;
    353 	if (ap)
    354 		((struct alias *)ap)->flag |= ALIASINUSE;
    355 	parsenextc = s;
    356 	parsenleft = len;
    357 	INTON;
    358 }
    359 
    360 void
    361 popstring()
    362 {
    363 	struct strpush *sp = parsefile->strpush;
    364 
    365 	INTOFF;
    366 	parsenextc = sp->prevstring;
    367 	parsenleft = sp->prevnleft;
    368 	parselleft = sp->prevlleft;
    369 /*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/
    370 	if (sp->ap)
    371 		sp->ap->flag &= ~ALIASINUSE;
    372 	parsefile->strpush = sp->prev;
    373 	if (sp != &(parsefile->basestrpush))
    374 		ckfree(sp);
    375 	INTON;
    376 }
    377 
    378 /*
    379  * Set the input to take input from a file.  If push is set, push the
    380  * old input onto the stack first.
    381  */
    382 
    383 void
    384 setinputfile(fname, push)
    385 	const char *fname;
    386 	int push;
    387 {
    388 	int fd;
    389 	int fd2;
    390 
    391 	INTOFF;
    392 	if ((fd = open(fname, O_RDONLY)) < 0)
    393 		error("Can't open %s", fname);
    394 	if (fd < 10) {
    395 		fd2 = copyfd(fd, 10);
    396 		close(fd);
    397 		if (fd2 < 0)
    398 			error("Out of file descriptors");
    399 		fd = fd2;
    400 	}
    401 	setinputfd(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(fd, push)
    413 	int fd, push;
    414 {
    415 	(void) fcntl(fd, F_SETFD, FD_CLOEXEC);
    416 	if (push) {
    417 		pushfile();
    418 		parsefile->buf = ckmalloc(BUFSIZ);
    419 	}
    420 	if (parsefile->fd > 0)
    421 		close(parsefile->fd);
    422 	parsefile->fd = fd;
    423 	if (parsefile->buf == NULL)
    424 		parsefile->buf = ckmalloc(BUFSIZ);
    425 	parselleft = parsenleft = 0;
    426 	plinno = 1;
    427 }
    428 
    429 
    430 /*
    431  * Like setinputfile, but takes input from a string.
    432  */
    433 
    434 void
    435 setinputstring(string, push)
    436 	char *string;
    437 	int push;
    438 	{
    439 	INTOFF;
    440 	if (push)
    441 		pushfile();
    442 	parsenextc = string;
    443 	parselleft = parsenleft = strlen(string);
    444 	parsefile->buf = NULL;
    445 	plinno = 1;
    446 	INTON;
    447 }
    448 
    449 
    450 
    451 /*
    452  * To handle the "." command, a stack of input files is used.  Pushfile
    453  * adds a new entry to the stack and popfile restores the previous level.
    454  */
    455 
    456 STATIC void
    457 pushfile() {
    458 	struct parsefile *pf;
    459 
    460 	parsefile->nleft = parsenleft;
    461 	parsefile->lleft = parselleft;
    462 	parsefile->nextc = parsenextc;
    463 	parsefile->linno = plinno;
    464 	pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile));
    465 	pf->prev = parsefile;
    466 	pf->fd = -1;
    467 	pf->strpush = NULL;
    468 	pf->basestrpush.prev = NULL;
    469 	parsefile = pf;
    470 }
    471 
    472 
    473 void
    474 popfile() {
    475 	struct parsefile *pf = parsefile;
    476 
    477 	INTOFF;
    478 	if (pf->fd >= 0)
    479 		close(pf->fd);
    480 	if (pf->buf)
    481 		ckfree(pf->buf);
    482 	while (pf->strpush)
    483 		popstring();
    484 	parsefile = pf->prev;
    485 	ckfree(pf);
    486 	parsenleft = parsefile->nleft;
    487 	parselleft = parsefile->lleft;
    488 	parsenextc = parsefile->nextc;
    489 	plinno = parsefile->linno;
    490 	INTON;
    491 }
    492 
    493 
    494 /*
    495  * Return to top level.
    496  */
    497 
    498 void
    499 popallfiles() {
    500 	while (parsefile != &basepf)
    501 		popfile();
    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 
    511 void
    512 closescript() {
    513 	popallfiles();
    514 	if (parsefile->fd > 0) {
    515 		close(parsefile->fd);
    516 		parsefile->fd = 0;
    517 	}
    518 }
    519