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input.c revision 1.17 
      1 /*	$NetBSD: input.c,v 1.17 1995/09/26 13:25:19 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 1.17 1995/09/26 13:25:19 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, &parsenleft);
    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 	if (parsefile->fd == 0 && hist && something) {
    297 		INTOFF;
    298 		history(hist, whichprompt == 1 ? H_ENTER : H_ADD, parsenextc);
    299 		INTON;
    300 	}
    301 
    302 	if (vflag) {
    303 		out2str(parsenextc);
    304 		flushout(out2);
    305 	}
    306 
    307 	*q = savec;
    308 
    309 	return *parsenextc++;
    310 }
    311 
    312 /*
    313  * Undo the last call to pgetc.  Only one character may be pushed back.
    314  * PEOF may be pushed back.
    315  */
    316 
    317 void
    318 pungetc() {
    319 	parsenleft++;
    320 	parsenextc--;
    321 }
    322 
    323 /*
    324  * Push a string back onto the input at this current parsefile level.
    325  * We handle aliases this way.
    326  */
    327 void
    328 pushstring(s, len, ap)
    329 	char *s;
    330 	int len;
    331 	void *ap;
    332 	{
    333 	struct strpush *sp;
    334 
    335 	INTOFF;
    336 /*dprintf("*** calling pushstring: %s, %d\n", s, len);*/
    337 	if (parsefile->strpush) {
    338 		sp = ckmalloc(sizeof (struct strpush));
    339 		sp->prev = parsefile->strpush;
    340 		parsefile->strpush = sp;
    341 	} else
    342 		sp = parsefile->strpush = &(parsefile->basestrpush);
    343 	sp->prevstring = parsenextc;
    344 	sp->prevnleft = parsenleft;
    345 	sp->prevlleft = parselleft;
    346 	sp->ap = (struct alias *)ap;
    347 	if (ap)
    348 		((struct alias *)ap)->flag |= ALIASINUSE;
    349 	parsenextc = s;
    350 	parsenleft = len;
    351 	INTON;
    352 }
    353 
    354 void
    355 popstring()
    356 {
    357 	struct strpush *sp = parsefile->strpush;
    358 
    359 	INTOFF;
    360 	parsenextc = sp->prevstring;
    361 	parsenleft = sp->prevnleft;
    362 	parselleft = sp->prevlleft;
    363 /*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/
    364 	if (sp->ap)
    365 		sp->ap->flag &= ~ALIASINUSE;
    366 	parsefile->strpush = sp->prev;
    367 	if (sp != &(parsefile->basestrpush))
    368 		ckfree(sp);
    369 	INTON;
    370 }
    371 
    372 /*
    373  * Set the input to take input from a file.  If push is set, push the
    374  * old input onto the stack first.
    375  */
    376 
    377 void
    378 setinputfile(fname, push)
    379 	char *fname;
    380 	int push;
    381 {
    382 	int fd;
    383 	int fd2;
    384 
    385 	INTOFF;
    386 	if ((fd = open(fname, O_RDONLY)) < 0)
    387 		error("Can't open %s", fname);
    388 	if (fd < 10) {
    389 		fd2 = copyfd(fd, 10);
    390 		close(fd);
    391 		if (fd2 < 0)
    392 			error("Out of file descriptors");
    393 		fd = fd2;
    394 	}
    395 	setinputfd(fd, push);
    396 	INTON;
    397 }
    398 
    399 
    400 /*
    401  * Like setinputfile, but takes an open file descriptor.  Call this with
    402  * interrupts off.
    403  */
    404 
    405 void
    406 setinputfd(fd, push)
    407 	int fd, push;
    408 {
    409 	if (push) {
    410 		pushfile();
    411 		parsefile->buf = ckmalloc(BUFSIZ);
    412 	}
    413 	if (parsefile->fd > 0)
    414 		close(parsefile->fd);
    415 	parsefile->fd = fd;
    416 	if (parsefile->buf == NULL)
    417 		parsefile->buf = ckmalloc(BUFSIZ);
    418 	parselleft = parsenleft = 0;
    419 	plinno = 1;
    420 }
    421 
    422 
    423 /*
    424  * Like setinputfile, but takes input from a string.
    425  */
    426 
    427 void
    428 setinputstring(string, push)
    429 	char *string;
    430 	int push;
    431 	{
    432 	INTOFF;
    433 	if (push)
    434 		pushfile();
    435 	parsenextc = string;
    436 	parselleft = parsenleft = strlen(string);
    437 	parsefile->buf = NULL;
    438 	plinno = 1;
    439 	INTON;
    440 }
    441 
    442 
    443 
    444 /*
    445  * To handle the "." command, a stack of input files is used.  Pushfile
    446  * adds a new entry to the stack and popfile restores the previous level.
    447  */
    448 
    449 STATIC void
    450 pushfile() {
    451 	struct parsefile *pf;
    452 
    453 	parsefile->nleft = parsenleft;
    454 	parsefile->lleft = parselleft;
    455 	parsefile->nextc = parsenextc;
    456 	parsefile->linno = plinno;
    457 	pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile));
    458 	pf->prev = parsefile;
    459 	pf->fd = -1;
    460 	pf->strpush = NULL;
    461 	pf->basestrpush.prev = NULL;
    462 	parsefile = pf;
    463 }
    464 
    465 
    466 void
    467 popfile() {
    468 	struct parsefile *pf = parsefile;
    469 
    470 	INTOFF;
    471 	if (pf->fd >= 0)
    472 		close(pf->fd);
    473 	if (pf->buf)
    474 		ckfree(pf->buf);
    475 	while (pf->strpush)
    476 		popstring();
    477 	parsefile = pf->prev;
    478 	ckfree(pf);
    479 	parsenleft = parsefile->nleft;
    480 	parselleft = parsefile->lleft;
    481 	parsenextc = parsefile->nextc;
    482 	plinno = parsefile->linno;
    483 	INTON;
    484 }
    485 
    486 
    487 /*
    488  * Return to top level.
    489  */
    490 
    491 void
    492 popallfiles() {
    493 	while (parsefile != &basepf)
    494 		popfile();
    495 }
    496 
    497 
    498 
    499 /*
    500  * Close the file(s) that the shell is reading commands from.  Called
    501  * after a fork is done.
    502  */
    503 
    504 void
    505 closescript() {
    506 	popallfiles();
    507 	if (parsefile->fd > 0) {
    508 		close(parsefile->fd);
    509 		parsefile->fd = 0;
    510 	}
    511 }
    512