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input.c revision 1.24 
      1 /*	$NetBSD: input.c,v 1.24 1997/03/13 21:57:33 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 1.24 1997/03/13 21:57:33 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 	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 #ifndef NO_HISTORY
    187 	if (parsefile->fd == 0 && el) {
    188 		const char *rl_cp;
    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 #endif
    199 		nr = read(parsefile->fd, parsenextc, BUFSIZ - 1);
    200 
    201 
    202 	if (nr <= 0) {
    203                 if (nr < 0) {
    204                         if (errno == EINTR)
    205                                 goto retry;
    206                         if (parsefile->fd == 0 && errno == EWOULDBLOCK) {
    207                                 int flags = fcntl(0, F_GETFL, 0);
    208                                 if (flags >= 0 && flags & O_NONBLOCK) {
    209                                         flags &=~ O_NONBLOCK;
    210                                         if (fcntl(0, F_SETFL, flags) >= 0) {
    211 						out2str("sh: turning off NDELAY mode\n");
    212                                                 goto retry;
    213                                         }
    214                                 }
    215                         }
    216                 }
    217                 nr = -1;
    218 	}
    219 	return nr;
    220 }
    221 
    222 /*
    223  * Refill the input buffer and return the next input character:
    224  *
    225  * 1) If a string was pushed back on the input, pop it;
    226  * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
    227  *    from a string so we can't refill the buffer, return EOF.
    228  * 3) If the is more stuff in this buffer, use it else call read to fill it.
    229  * 4) Process input up to the next newline, deleting nul characters.
    230  */
    231 
    232 int
    233 preadbuffer()
    234 {
    235 	char *p, *q;
    236 	int more;
    237 	int something;
    238 	extern EditLine *el;
    239 	char savec;
    240 
    241 	if (parsefile->strpush) {
    242 		popstring();
    243 		if (--parsenleft >= 0)
    244 			return (*parsenextc++);
    245 	}
    246 	if (parsenleft == EOF_NLEFT || parsefile->buf == NULL)
    247 		return PEOF;
    248 	flushout(&output);
    249 	flushout(&errout);
    250 
    251 again:
    252 	if (parselleft <= 0) {
    253 		if ((parselleft = pread()) == -1) {
    254 			parselleft = parsenleft = EOF_NLEFT;
    255 			return PEOF;
    256 		}
    257 	}
    258 
    259 	q = p = parsenextc;
    260 
    261 	/* delete nul characters */
    262 	something = 0;
    263 	for (more = 1; more;) {
    264 		switch (*p) {
    265 		case '\0':
    266 			p++;	/* Skip nul */
    267 			goto check;
    268 
    269 		case '\t':
    270 		case ' ':
    271 			break;
    272 
    273 		case '\n':
    274 			parsenleft = q - parsenextc;
    275 			more = 0; /* Stop processing here */
    276 			break;
    277 
    278 		default:
    279 			something = 1;
    280 			break;
    281 		}
    282 
    283 		*q++ = *p++;
    284 check:
    285 		if (--parselleft <= 0) {
    286 			parsenleft = q - parsenextc - 1;
    287 			if (parsenleft < 0)
    288 				goto again;
    289 			*q = '\0';
    290 			more = 0;
    291 		}
    292 	}
    293 
    294 	savec = *q;
    295 	*q = '\0';
    296 
    297 #ifndef NO_HISTORY
    298 	if (parsefile->fd == 0 && hist && something) {
    299 		INTOFF;
    300 		history(hist, whichprompt == 1 ? H_ENTER : H_ADD, parsenextc);
    301 		INTON;
    302 	}
    303 #endif
    304 
    305 	if (vflag) {
    306 		out2str(parsenextc);
    307 		flushout(out2);
    308 	}
    309 
    310 	*q = savec;
    311 
    312 	return *parsenextc++;
    313 }
    314 
    315 /*
    316  * Undo the last call to pgetc.  Only one character may be pushed back.
    317  * PEOF may be pushed back.
    318  */
    319 
    320 void
    321 pungetc() {
    322 	parsenleft++;
    323 	parsenextc--;
    324 }
    325 
    326 /*
    327  * Push a string back onto the input at this current parsefile level.
    328  * We handle aliases this way.
    329  */
    330 void
    331 pushstring(s, len, ap)
    332 	char *s;
    333 	int len;
    334 	void *ap;
    335 	{
    336 	struct strpush *sp;
    337 
    338 	INTOFF;
    339 /*dprintf("*** calling pushstring: %s, %d\n", s, len);*/
    340 	if (parsefile->strpush) {
    341 		sp = ckmalloc(sizeof (struct strpush));
    342 		sp->prev = parsefile->strpush;
    343 		parsefile->strpush = sp;
    344 	} else
    345 		sp = parsefile->strpush = &(parsefile->basestrpush);
    346 	sp->prevstring = parsenextc;
    347 	sp->prevnleft = parsenleft;
    348 	sp->prevlleft = parselleft;
    349 	sp->ap = (struct alias *)ap;
    350 	if (ap)
    351 		((struct alias *)ap)->flag |= ALIASINUSE;
    352 	parsenextc = s;
    353 	parsenleft = len;
    354 	INTON;
    355 }
    356 
    357 void
    358 popstring()
    359 {
    360 	struct strpush *sp = parsefile->strpush;
    361 
    362 	INTOFF;
    363 	parsenextc = sp->prevstring;
    364 	parsenleft = sp->prevnleft;
    365 	parselleft = sp->prevlleft;
    366 /*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/
    367 	if (sp->ap)
    368 		sp->ap->flag &= ~ALIASINUSE;
    369 	parsefile->strpush = sp->prev;
    370 	if (sp != &(parsefile->basestrpush))
    371 		ckfree(sp);
    372 	INTON;
    373 }
    374 
    375 /*
    376  * Set the input to take input from a file.  If push is set, push the
    377  * old input onto the stack first.
    378  */
    379 
    380 void
    381 setinputfile(fname, push)
    382 	char *fname;
    383 	int push;
    384 {
    385 	int fd;
    386 	int fd2;
    387 
    388 	INTOFF;
    389 	if ((fd = open(fname, O_RDONLY)) < 0)
    390 		error("Can't open %s", fname);
    391 	if (fd < 10) {
    392 		fd2 = copyfd(fd, 10);
    393 		close(fd);
    394 		if (fd2 < 0)
    395 			error("Out of file descriptors");
    396 		fd = fd2;
    397 	}
    398 	setinputfd(fd, push);
    399 	INTON;
    400 }
    401 
    402 
    403 /*
    404  * Like setinputfile, but takes an open file descriptor.  Call this with
    405  * interrupts off.
    406  */
    407 
    408 void
    409 setinputfd(fd, push)
    410 	int fd, push;
    411 {
    412 	(void) fcntl(fd, F_SETFD, FD_CLOEXEC);
    413 	if (push) {
    414 		pushfile();
    415 		parsefile->buf = ckmalloc(BUFSIZ);
    416 	}
    417 	if (parsefile->fd > 0)
    418 		close(parsefile->fd);
    419 	parsefile->fd = fd;
    420 	if (parsefile->buf == NULL)
    421 		parsefile->buf = ckmalloc(BUFSIZ);
    422 	parselleft = parsenleft = 0;
    423 	plinno = 1;
    424 }
    425 
    426 
    427 /*
    428  * Like setinputfile, but takes input from a string.
    429  */
    430 
    431 void
    432 setinputstring(string, push)
    433 	char *string;
    434 	int push;
    435 	{
    436 	INTOFF;
    437 	if (push)
    438 		pushfile();
    439 	parsenextc = string;
    440 	parselleft = parsenleft = strlen(string);
    441 	parsefile->buf = NULL;
    442 	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() {
    455 	struct parsefile *pf;
    456 
    457 	parsefile->nleft = parsenleft;
    458 	parsefile->lleft = parselleft;
    459 	parsefile->nextc = parsenextc;
    460 	parsefile->linno = plinno;
    461 	pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile));
    462 	pf->prev = parsefile;
    463 	pf->fd = -1;
    464 	pf->strpush = NULL;
    465 	pf->basestrpush.prev = NULL;
    466 	parsefile = pf;
    467 }
    468 
    469 
    470 void
    471 popfile() {
    472 	struct parsefile *pf = parsefile;
    473 
    474 	INTOFF;
    475 	if (pf->fd >= 0)
    476 		close(pf->fd);
    477 	if (pf->buf)
    478 		ckfree(pf->buf);
    479 	while (pf->strpush)
    480 		popstring();
    481 	parsefile = pf->prev;
    482 	ckfree(pf);
    483 	parsenleft = parsefile->nleft;
    484 	parselleft = parsefile->lleft;
    485 	parsenextc = parsefile->nextc;
    486 	plinno = parsefile->linno;
    487 	INTON;
    488 }
    489 
    490 
    491 /*
    492  * Return to top level.
    493  */
    494 
    495 void
    496 popallfiles() {
    497 	while (parsefile != &basepf)
    498 		popfile();
    499 }
    500 
    501 
    502 
    503 /*
    504  * Close the file(s) that the shell is reading commands from.  Called
    505  * after a fork is done.
    506  */
    507 
    508 void
    509 closescript() {
    510 	popallfiles();
    511 	if (parsefile->fd > 0) {
    512 		close(parsefile->fd);
    513 		parsefile->fd = 0;
    514 	}
    515 }
    516