Home | History | Annotate | Line # | Download | only in sh
input.c revision 1.20 
      1 /*	$NetBSD: input.c,v 1.20 1996/10/16 15:45:08 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 #ifndef lint
     40 #if 0
     41 static char sccsid[] = "@(#)input.c	8.3 (Berkeley) 6/9/95";
     42 #else
     43 static char rcsid[] = "$NetBSD: input.c,v 1.20 1996/10/16 15:45:08 christos Exp $";
     44 #endif
     45 #endif /* not lint */
     46 
     47 #include <stdio.h>	/* defines BUFSIZ */
     48 #include <fcntl.h>
     49 #include <errno.h>
     50 #include <unistd.h>
     51 #include <stdlib.h>
     52 #include <string.h>
     53 
     54 /*
     55  * This file implements the input routines used by the parser.
     56  */
     57 
     58 #include "shell.h"
     59 #include "redir.h"
     60 #include "syntax.h"
     61 #include "input.h"
     62 #include "output.h"
     63 #include "options.h"
     64 #include "memalloc.h"
     65 #include "error.h"
     66 #include "alias.h"
     67 #include "parser.h"
     68 #include "myhistedit.h"
     69 
     70 #define EOF_NLEFT -99		/* value of parsenleft when EOF pushed back */
     71 
     72 MKINIT
     73 struct strpush {
     74 	struct strpush *prev;	/* preceding string on stack */
     75 	char *prevstring;
     76 	int prevnleft;
     77 	int prevlleft;
     78 	struct alias *ap;	/* if push was associated with an alias */
     79 };
     80 
     81 /*
     82  * The parsefile structure pointed to by the global variable parsefile
     83  * contains information about the current file being read.
     84  */
     85 
     86 MKINIT
     87 struct parsefile {
     88 	struct parsefile *prev;	/* preceding file on stack */
     89 	int linno;		/* current line */
     90 	int fd;			/* file descriptor (or -1 if string) */
     91 	int nleft;		/* number of chars left in this line */
     92 	int lleft;		/* number of chars left in this buffer */
     93 	char *nextc;		/* next char in buffer */
     94 	char *buf;		/* input buffer */
     95 	struct strpush *strpush; /* for pushing strings at this level */
     96 	struct strpush basestrpush; /* so pushing one is fast */
     97 };
     98 
     99 
    100 int plinno = 1;			/* input line number */
    101 MKINIT int parsenleft;		/* copy of parsefile->nleft */
    102 MKINIT int parselleft;		/* copy of parsefile->lleft */
    103 char *parsenextc;		/* copy of parsefile->nextc */
    104 MKINIT struct parsefile basepf;	/* top level input file */
    105 char basebuf[BUFSIZ];		/* buffer for top level input file */
    106 struct parsefile *parsefile = &basepf;	/* current input file */
    107 int init_editline = 0;		/* editline library initialized? */
    108 int whichprompt;		/* 1 == PS1, 2 == PS2 */
    109 
    110 EditLine *el;			/* cookie for editline package */
    111 
    112 STATIC void pushfile __P((void));
    113 static int pread __P((void));
    114 
    115 #ifdef mkinit
    116 INCLUDE "input.h"
    117 INCLUDE "error.h"
    118 
    119 INIT {
    120 	extern char basebuf[];
    121 
    122 	basepf.nextc = basepf.buf = basebuf;
    123 }
    124 
    125 RESET {
    126 	if (exception != EXSHELLPROC)
    127 		parselleft = parsenleft = 0;	/* clear input buffer */
    128 	popallfiles();
    129 }
    130 
    131 SHELLPROC {
    132 	popallfiles();
    133 }
    134 #endif
    135 
    136 
    137 /*
    138  * Read a line from the script.
    139  */
    140 
    141 char *
    142 pfgets(line, len)
    143 	char *line;
    144 	int len;
    145 {
    146 	register char *p = line;
    147 	int nleft = len;
    148 	int c;
    149 
    150 	while (--nleft > 0) {
    151 		c = pgetc_macro();
    152 		if (c == PEOF) {
    153 			if (p == line)
    154 				return NULL;
    155 			break;
    156 		}
    157 		*p++ = c;
    158 		if (c == '\n')
    159 			break;
    160 	}
    161 	*p = '\0';
    162 	return line;
    163 }
    164 
    165 
    166 
    167 /*
    168  * Read a character from the script, returning PEOF on end of file.
    169  * Nul characters in the input are silently discarded.
    170  */
    171 
    172 int
    173 pgetc()
    174 {
    175 	return pgetc_macro();
    176 }
    177 
    178 
    179 static int
    180 pread()
    181 {
    182 	int nr;
    183 	parsenextc = parsefile->buf;
    184 
    185 retry:
    186 	if (parsefile->fd == 0 && el) {
    187 		const char *rl_cp;
    188 		int len;
    189 
    190 		rl_cp = el_gets(el, &nr);
    191 		if (rl_cp == NULL)
    192 			nr = 0;
    193 		else {
    194 			/* XXX - BUFSIZE should redesign so not necessary */
    195 			(void) strcpy(parsenextc, rl_cp);
    196 		}
    197 	} else {
    198 		nr = read(parsefile->fd, parsenextc, BUFSIZ - 1);
    199 	}
    200 
    201 	if (nr <= 0) {
    202                 if (nr < 0) {
    203                         if (errno == EINTR)
    204                                 goto retry;
    205                         if (parsefile->fd == 0 && errno == EWOULDBLOCK) {
    206                                 int flags = fcntl(0, F_GETFL, 0);
    207                                 if (flags >= 0 && flags & O_NONBLOCK) {
    208                                         flags &=~ O_NONBLOCK;
    209                                         if (fcntl(0, F_SETFL, flags) >= 0) {
    210 						out2str("sh: turning off NDELAY mode\n");
    211                                                 goto retry;
    212                                         }
    213                                 }
    214                         }
    215                 }
    216                 nr = -1;
    217 	}
    218 	return nr;
    219 }
    220 
    221 /*
    222  * Refill the input buffer and return the next input character:
    223  *
    224  * 1) If a string was pushed back on the input, pop it;
    225  * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
    226  *    from a string so we can't refill the buffer, return EOF.
    227  * 3) If the is more stuff in this buffer, use it else call read to fill it.
    228  * 4) Process input up to the next newline, deleting nul characters.
    229  */
    230 
    231 int
    232 preadbuffer()
    233 {
    234 	char *p, *q;
    235 	int more;
    236 	int something;
    237 	extern EditLine *el;
    238 	char savec;
    239 
    240 	if (parsefile->strpush) {
    241 		popstring();
    242 		if (--parsenleft >= 0)
    243 			return (*parsenextc++);
    244 	}
    245 	if (parsenleft == EOF_NLEFT || parsefile->buf == NULL)
    246 		return PEOF;
    247 	flushout(&output);
    248 	flushout(&errout);
    249 
    250 again:
    251 	if (parselleft <= 0) {
    252 		if ((parselleft = pread()) == -1) {
    253 			parselleft = parsenleft = EOF_NLEFT;
    254 			return PEOF;
    255 		}
    256 	}
    257 
    258 	q = p = parsenextc;
    259 
    260 	/* delete nul characters */
    261 	something = 0;
    262 	for (more = 1; more;) {
    263 		switch (*p) {
    264 		case '\0':
    265 			p++;	/* Skip nul */
    266 			goto check;
    267 
    268 		case '\t':
    269 		case ' ':
    270 			break;
    271 
    272 		case '\n':
    273 			parsenleft = q - parsenextc;
    274 			more = 0; /* Stop processing here */
    275 			break;
    276 
    277 		default:
    278 			something = 1;
    279 			break;
    280 		}
    281 
    282 		*q++ = *p++;
    283 check:
    284 		if (--parselleft <= 0) {
    285 			parsenleft = q - parsenextc - 1;
    286 			if (parsenleft < 0)
    287 				goto again;
    288 			*q = '\0';
    289 			more = 0;
    290 		}
    291 	}
    292 
    293 	savec = *q;
    294 	*q = '\0';
    295 
    296 #ifndef NO_HISTORY
    297 	if (parsefile->fd == 0 && hist && something) {
    298 		INTOFF;
    299 		history(hist, whichprompt == 1 ? H_ENTER : H_ADD, parsenextc);
    300 		INTON;
    301 	}
    302 #endif
    303 
    304 	if (vflag) {
    305 		out2str(parsenextc);
    306 		flushout(out2);
    307 	}
    308 
    309 	*q = savec;
    310 
    311 	return *parsenextc++;
    312 }
    313 
    314 /*
    315  * Undo the last call to pgetc.  Only one character may be pushed back.
    316  * PEOF may be pushed back.
    317  */
    318 
    319 void
    320 pungetc() {
    321 	parsenleft++;
    322 	parsenextc--;
    323 }
    324 
    325 /*
    326  * Push a string back onto the input at this current parsefile level.
    327  * We handle aliases this way.
    328  */
    329 void
    330 pushstring(s, len, ap)
    331 	char *s;
    332 	int len;
    333 	void *ap;
    334 	{
    335 	struct strpush *sp;
    336 
    337 	INTOFF;
    338 /*dprintf("*** calling pushstring: %s, %d\n", s, len);*/
    339 	if (parsefile->strpush) {
    340 		sp = ckmalloc(sizeof (struct strpush));
    341 		sp->prev = parsefile->strpush;
    342 		parsefile->strpush = sp;
    343 	} else
    344 		sp = parsefile->strpush = &(parsefile->basestrpush);
    345 	sp->prevstring = parsenextc;
    346 	sp->prevnleft = parsenleft;
    347 	sp->prevlleft = parselleft;
    348 	sp->ap = (struct alias *)ap;
    349 	if (ap)
    350 		((struct alias *)ap)->flag |= ALIASINUSE;
    351 	parsenextc = s;
    352 	parsenleft = len;
    353 	INTON;
    354 }
    355 
    356 void
    357 popstring()
    358 {
    359 	struct strpush *sp = parsefile->strpush;
    360 
    361 	INTOFF;
    362 	parsenextc = sp->prevstring;
    363 	parsenleft = sp->prevnleft;
    364 	parselleft = sp->prevlleft;
    365 /*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/
    366 	if (sp->ap)
    367 		sp->ap->flag &= ~ALIASINUSE;
    368 	parsefile->strpush = sp->prev;
    369 	if (sp != &(parsefile->basestrpush))
    370 		ckfree(sp);
    371 	INTON;
    372 }
    373 
    374 /*
    375  * Set the input to take input from a file.  If push is set, push the
    376  * old input onto the stack first.
    377  */
    378 
    379 void
    380 setinputfile(fname, push)
    381 	char *fname;
    382 	int push;
    383 {
    384 	int fd;
    385 	int fd2;
    386 
    387 	INTOFF;
    388 	if ((fd = open(fname, O_RDONLY)) < 0)
    389 		error("Can't open %s", fname);
    390 	if (fd < 10) {
    391 		fd2 = copyfd(fd, 10);
    392 		close(fd);
    393 		if (fd2 < 0)
    394 			error("Out of file descriptors");
    395 		fd = fd2;
    396 	}
    397 	setinputfd(fd, push);
    398 	INTON;
    399 }
    400 
    401 
    402 /*
    403  * Like setinputfile, but takes an open file descriptor.  Call this with
    404  * interrupts off.
    405  */
    406 
    407 void
    408 setinputfd(fd, push)
    409 	int fd, push;
    410 {
    411 	if (push) {
    412 		pushfile();
    413 		parsefile->buf = ckmalloc(BUFSIZ);
    414 	}
    415 	if (parsefile->fd > 0)
    416 		close(parsefile->fd);
    417 	parsefile->fd = fd;
    418 	if (parsefile->buf == NULL)
    419 		parsefile->buf = ckmalloc(BUFSIZ);
    420 	parselleft = parsenleft = 0;
    421 	plinno = 1;
    422 }
    423 
    424 
    425 /*
    426  * Like setinputfile, but takes input from a string.
    427  */
    428 
    429 void
    430 setinputstring(string, push)
    431 	char *string;
    432 	int push;
    433 	{
    434 	INTOFF;
    435 	if (push)
    436 		pushfile();
    437 	parsenextc = string;
    438 	parselleft = parsenleft = strlen(string);
    439 	parsefile->buf = NULL;
    440 	plinno = 1;
    441 	INTON;
    442 }
    443 
    444 
    445 
    446 /*
    447  * To handle the "." command, a stack of input files is used.  Pushfile
    448  * adds a new entry to the stack and popfile restores the previous level.
    449  */
    450 
    451 STATIC void
    452 pushfile() {
    453 	struct parsefile *pf;
    454 
    455 	parsefile->nleft = parsenleft;
    456 	parsefile->lleft = parselleft;
    457 	parsefile->nextc = parsenextc;
    458 	parsefile->linno = plinno;
    459 	pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile));
    460 	pf->prev = parsefile;
    461 	pf->fd = -1;
    462 	pf->strpush = NULL;
    463 	pf->basestrpush.prev = NULL;
    464 	parsefile = pf;
    465 }
    466 
    467 
    468 void
    469 popfile() {
    470 	struct parsefile *pf = parsefile;
    471 
    472 	INTOFF;
    473 	if (pf->fd >= 0)
    474 		close(pf->fd);
    475 	if (pf->buf)
    476 		ckfree(pf->buf);
    477 	while (pf->strpush)
    478 		popstring();
    479 	parsefile = pf->prev;
    480 	ckfree(pf);
    481 	parsenleft = parsefile->nleft;
    482 	parselleft = parsefile->lleft;
    483 	parsenextc = parsefile->nextc;
    484 	plinno = parsefile->linno;
    485 	INTON;
    486 }
    487 
    488 
    489 /*
    490  * Return to top level.
    491  */
    492 
    493 void
    494 popallfiles() {
    495 	while (parsefile != &basepf)
    496 		popfile();
    497 }
    498 
    499 
    500 
    501 /*
    502  * Close the file(s) that the shell is reading commands from.  Called
    503  * after a fork is done.
    504  */
    505 
    506 void
    507 closescript() {
    508 	popallfiles();
    509 	if (parsefile->fd > 0) {
    510 		close(parsefile->fd);
    511 		parsefile->fd = 0;
    512 	}
    513 }
    514