input.c revision 1.12 
1/*-
2 * Copyright (c) 1991, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Kenneth Almquist.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 *    must display the following acknowledgement:
18 *	This product includes software developed by the University of
19 *	California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 *    may be used to endorse or promote products derived from this software
22 *    without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37#ifndef lint
38/*static char sccsid[] = "from: @(#)input.c	8.1 (Berkeley) 5/31/93";*/
39static char *rcsid = "$Id: input.c,v 1.12 1994/12/23 13:24:10 cgd Exp $";
40#endif /* not lint */
41
42/*
43 * This file implements the input routines used by the parser.
44 */
45
46#include <stdio.h>	/* defines BUFSIZ */
47#include <string.h>
48#include <fcntl.h>
49#include <errno.h>
50#include <unistd.h>
51#include "shell.h"
52#include "syntax.h"
53#include "input.h"
54#include "output.h"
55#include "options.h"
56#include "memalloc.h"
57#include "error.h"
58#include "alias.h"
59#include "parser.h"
60#include "extern.h"
61#ifndef NO_HISTORY
62#include "myhistedit.h"
63#endif
64
65#define EOF_NLEFT -99		/* value of parsenleft when EOF pushed back */
66
67MKINIT
68struct strpush {
69	struct strpush *prev;	/* preceding string on stack */
70	char *prevstring;
71	int prevnleft;
72	struct alias *ap;	/* if push was associated with an alias */
73};
74
75/*
76 * The parsefile structure pointed to by the global variable parsefile
77 * contains information about the current file being read.
78 */
79
80MKINIT
81struct parsefile {
82	struct parsefile *prev;	/* preceding file on stack */
83	int linno;		/* current line */
84	int fd;			/* file descriptor (or -1 if string) */
85	int nleft;		/* number of chars left in buffer */
86	char *nextc;		/* next char in buffer */
87	char *buf;		/* input buffer */
88	struct strpush *strpush; /* for pushing strings at this level */
89	struct strpush basestrpush; /* so pushing one is fast */
90};
91
92
93int plinno = 1;			/* input line number */
94MKINIT int parsenleft;		/* copy of parsefile->nleft */
95char *parsenextc;		/* copy of parsefile->nextc */
96MKINIT struct parsefile basepf;	/* top level input file */
97char basebuf[BUFSIZ];		/* buffer for top level input file */
98struct parsefile *parsefile = &basepf;	/* current input file */
99char *pushedstring;		/* copy of parsenextc when text pushed back */
100int pushednleft;		/* copy of parsenleft when text pushed back */
101int init_editline = 0;		/* editline library initialized? */
102int whichprompt;		/* 1 == PS1, 2 == PS2 */
103
104#ifndef NO_HISTORY
105EditLine *el;			/* cookie for editline package */
106#endif
107
108#ifdef __STDC__
109STATIC void pushfile(void);
110#else
111STATIC void pushfile();
112#endif
113
114void popstring();
115
116
117
118#ifdef mkinit
119INCLUDE "input.h"
120INCLUDE "error.h"
121
122INIT {
123	extern char basebuf[];
124
125	basepf.nextc = basepf.buf = basebuf;
126}
127
128RESET {
129	if (exception != EXSHELLPROC)
130		parsenleft = 0;            /* clear input buffer */
131	popallfiles();
132}
133
134SHELLPROC {
135	popallfiles();
136}
137#endif
138
139
140/*
141 * Read a line from the script.
142 */
143
144char *
145pfgets(line, len)
146	char *line;
147	int len;
148{
149	register char *p = line;
150	int nleft = len;
151	int c;
152
153	while (--nleft > 0) {
154		c = pgetc_macro();
155		if (c == PEOF) {
156			if (p == line)
157				return NULL;
158			break;
159		}
160		*p++ = c;
161		if (c == '\n')
162			break;
163	}
164	*p = '\0';
165	return line;
166}
167
168
169
170/*
171 * Read a character from the script, returning PEOF on end of file.
172 * Nul characters in the input are silently discarded.
173 */
174
175int
176pgetc() {
177	return pgetc_macro();
178}
179
180
181/*
182 * Refill the input buffer and return the next input character:
183 *
184 * 1) If a string was pushed back on the input, pop it;
185 * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
186 *    from a string so we can't refill the buffer, return EOF.
187 * 3) Call read to read in the characters.
188 * 4) Delete all nul characters from the buffer.
189 */
190
191int
192preadbuffer() {
193	register char *p, *q;
194	register int i;
195	register int something;
196#ifndef NO_HISTORY
197	extern EditLine *el;
198#endif
199
200	if (parsefile->strpush) {
201		popstring();
202		if (--parsenleft >= 0)
203			return (*parsenextc++);
204	}
205	if (parsenleft == EOF_NLEFT || parsefile->buf == NULL)
206		return PEOF;
207	flushout(&output);
208	flushout(&errout);
209retry:
210	p = parsenextc = parsefile->buf;
211#ifndef NO_HISTORY
212	if (parsefile->fd == 0 && el) {
213		const char *rl_cp;
214		int len;
215
216		rl_cp = el_gets(el, &len);
217		if (rl_cp == NULL) {
218			i = 0;
219			goto eof;
220		}
221		strcpy(p, rl_cp);  /* XXX - BUFSIZE should redesign so not necessary */
222		i = len;
223
224	} else {
225#endif
226regular_read:
227		i = read(parsefile->fd, p, BUFSIZ - 1);
228#ifndef NO_HISTORY
229	}
230#endif
231eof:
232	if (i <= 0) {
233                if (i < 0) {
234                        if (errno == EINTR)
235                                goto retry;
236                        if (parsefile->fd == 0 && errno == EWOULDBLOCK) {
237                                int flags = fcntl(0, F_GETFL, 0);
238                                if (flags >= 0 && flags & O_NONBLOCK) {
239                                        flags &=~ O_NONBLOCK;
240                                        if (fcntl(0, F_SETFL, flags) >= 0) {
241						out2str("sh: turning off NDELAY mode\n");
242                                                goto retry;
243                                        }
244                                }
245                        }
246                }
247                parsenleft = EOF_NLEFT;
248                return PEOF;
249	}
250	parsenleft = i - 1;	/* we're returning one char in this call */
251
252	/* delete nul characters */
253	something = 0;
254	for (;;) {
255		if (*p == '\0')
256			break;
257		if (*p != ' ' && *p != '\t' && *p != '\n')
258			something = 1;
259		p++;
260		if (--i <= 0) {
261			*p = '\0';
262			goto done;		/* no nul characters */
263		}
264	}
265	/*
266	 * remove nuls
267	 */
268	q = p++;
269	while (--i > 0) {
270		if (*p != '\0')
271			*q++ = *p;
272		p++;
273	}
274	*q = '\0';
275	if (q == parsefile->buf)
276		goto retry;			/* buffer contained nothing but nuls */
277	parsenleft = q - parsefile->buf - 1;
278
279done:
280#ifndef NO_HISTORY
281	if (parsefile->fd == 0 && hist && something) {
282		INTOFF;
283		history(hist, whichprompt == 1 ? H_ENTER : H_ADD,
284			   parsefile->buf);
285		INTON;
286	}
287#endif
288	if (vflag) {
289		/*
290		 * This isn't right.  Most shells coordinate it with
291		 * reading a line at a time.  I honestly don't know if its
292		 * worth it.
293		 */
294		i = parsenleft + 1;
295		p = parsefile->buf;
296		for (; i--; p++)
297			out2c(*p)
298		flushout(out2);
299	}
300	return *parsenextc++;
301}
302
303/*
304 * Undo the last call to pgetc.  Only one character may be pushed back.
305 * PEOF may be pushed back.
306 */
307
308void
309pungetc() {
310	parsenleft++;
311	parsenextc--;
312}
313
314/*
315 * Push a string back onto the input at this current parsefile level.
316 * We handle aliases this way.
317 */
318void
319pushstring(s, len, ap)
320	char *s;
321	int len;
322	void *ap;
323	{
324	struct strpush *sp;
325
326	INTOFF;
327/*dprintf("*** calling pushstring: %s, %d\n", s, len);*/
328	if (parsefile->strpush) {
329		sp = ckmalloc(sizeof (struct strpush));
330		sp->prev = parsefile->strpush;
331		parsefile->strpush = sp;
332	} else
333		sp = parsefile->strpush = &(parsefile->basestrpush);
334	sp->prevstring = parsenextc;
335	sp->prevnleft = parsenleft;
336	sp->ap = (struct alias *)ap;
337	if (ap)
338		((struct alias *)ap)->flag |= ALIASINUSE;
339	parsenextc = s;
340	parsenleft = len;
341	INTON;
342}
343
344void
345popstring()
346{
347	struct strpush *sp = parsefile->strpush;
348
349	INTOFF;
350	parsenextc = sp->prevstring;
351	parsenleft = sp->prevnleft;
352/*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/
353	if (sp->ap)
354		sp->ap->flag &= ~ALIASINUSE;
355	parsefile->strpush = sp->prev;
356	if (sp != &(parsefile->basestrpush))
357		ckfree(sp);
358	INTON;
359}
360
361/*
362 * Set the input to take input from a file.  If push is set, push the
363 * old input onto the stack first.
364 */
365
366void
367setinputfile(fname, push)
368	char *fname;
369	int push;
370{
371	int fd;
372	int fd2;
373
374	INTOFF;
375	if ((fd = open(fname, O_RDONLY)) < 0)
376		error("Can't open %s", fname);
377	if (fd < 10) {
378		fd2 = copyfd(fd, 10);
379		close(fd);
380		if (fd2 < 0)
381			error("Out of file descriptors");
382		fd = fd2;
383	}
384	setinputfd(fd, push);
385	INTON;
386}
387
388
389/*
390 * Like setinputfile, but takes an open file descriptor.  Call this with
391 * interrupts off.
392 */
393
394void
395setinputfd(fd, push)
396	int fd;
397	int push;
398{
399	if (push) {
400		pushfile();
401		parsefile->buf = ckmalloc(BUFSIZ);
402	}
403	if (parsefile->fd > 0)
404		close(parsefile->fd);
405	parsefile->fd = fd;
406	if (parsefile->buf == NULL)
407		parsefile->buf = ckmalloc(BUFSIZ);
408	parsenleft = 0;
409	plinno = 1;
410}
411
412
413/*
414 * Like setinputfile, but takes input from a string.
415 */
416
417void
418setinputstring(string, push)
419	char *string;
420	int push;
421{
422	INTOFF;
423	if (push)
424		pushfile();
425	parsenextc = string;
426	parsenleft = strlen(string);
427	parsefile->buf = NULL;
428	plinno = 1;
429	INTON;
430}
431
432
433
434/*
435 * To handle the "." command, a stack of input files is used.  Pushfile
436 * adds a new entry to the stack and popfile restores the previous level.
437 */
438
439STATIC void
440pushfile() {
441	struct parsefile *pf;
442
443	parsefile->nleft = parsenleft;
444	parsefile->nextc = parsenextc;
445	parsefile->linno = plinno;
446	pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile));
447	pf->prev = parsefile;
448	pf->fd = -1;
449	pf->strpush = NULL;
450	pf->basestrpush.prev = NULL;
451	parsefile = pf;
452}
453
454
455void
456popfile() {
457	struct parsefile *pf = parsefile;
458
459	INTOFF;
460	if (pf->fd >= 0)
461		close(pf->fd);
462	if (pf->buf)
463		ckfree(pf->buf);
464	while (pf->strpush)
465		popstring();
466	parsefile = pf->prev;
467	ckfree(pf);
468	parsenleft = parsefile->nleft;
469	parsenextc = parsefile->nextc;
470	plinno = parsefile->linno;
471	INTON;
472}
473
474
475/*
476 * Return to top level.
477 */
478
479void
480popallfiles() {
481	while (parsefile != &basepf)
482		popfile();
483}
484
485
486
487/*
488 * Close the file(s) that the shell is reading commands from.  Called
489 * after a fork is done.
490 */
491
492void
493closescript() {
494	popallfiles();
495	if (parsefile->fd > 0) {
496		close(parsefile->fd);
497		parsefile->fd = 0;
498	}
499}
500