usr/dash/input.c

/*-
 * Copyright (c) 1991, 1993
 *	The Regents of the University of California.  All rights reserved.
 * Copyright (c) 1997-2005
 *	Herbert Xu <herbert@gondor.apana.org.au>.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Kenneth Almquist.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <stdio.h>	/* defines BUFSIZ */
#include <fcntl.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>

/*
 * This file implements the input routines used by the parser.
 */

#include "shell.h"
#include "redir.h"
#include "syntax.h"
#include "input.h"
#include "output.h"
#include "options.h"
#include "memalloc.h"
#include "error.h"
#include "alias.h"
#include "parser.h"
#include "main.h"
#ifndef SMALL
#include "myhistedit.h"
#endif

#ifdef HETIO
#include "hetio.h"
#endif

#define EOF_NLEFT -99		/* value of parsenleft when EOF pushed back */
#define IBUFSIZ (BUFSIZ + 1)

MKINIT
struct strpush {
	struct strpush *prev;	/* preceding string on stack */
	char *prevstring;
	int prevnleft;
	struct alias *ap;	/* if push was associated with an alias */
	char *string;		/* remember the string since it may change */
};

/*
 * The parsefile structure pointed to by the global variable parsefile
 * contains information about the current file being read.
 */

MKINIT
struct parsefile {
	struct parsefile *prev;	/* preceding file on stack */
	int linno;		/* current line */
	int fd;			/* file descriptor (or -1 if string) */
	int nleft;		/* number of chars left in this line */
	int lleft;		/* number of chars left in this buffer */
	char *nextc;		/* next char in buffer */
	char *buf;		/* input buffer */
	struct strpush *strpush; /* for pushing strings at this level */
	struct strpush basestrpush; /* so pushing one is fast */
};


int plinno = 1;			/* input line number */
int parsenleft;			/* copy of parsefile->nleft */
MKINIT int parselleft;		/* copy of parsefile->lleft */
char *parsenextc;		/* copy of parsefile->nextc */
MKINIT struct parsefile basepf;	/* top level input file */
MKINIT char basebuf[IBUFSIZ];	/* buffer for top level input file */
struct parsefile *parsefile = &basepf;	/* current input file */
int whichprompt;		/* 1 == PS1, 2 == PS2 */

#ifndef SMALL
EditLine *el;			/* cookie for editline package */
#endif

STATIC void pushfile(void);
static int preadfd(void);

#ifdef mkinit
INCLUDE <stdio.h>
INCLUDE "input.h"
INCLUDE "error.h"

INIT {
	basepf.nextc = basepf.buf = basebuf;
}

RESET {
	parselleft = parsenleft = 0;	/* clear input buffer */
	popallfiles();
}
#endif


/*
 * Read a line from the script.
 */

char *
pfgets(char *line, int len)
{
	char *p = line;
	int nleft = len;
	int c;

	while (--nleft > 0) {
		c = pgetc2();
		if (c == PEOF) {
			if (p == line)
				return NULL;
			break;
		}
		*p++ = c;
		if (c == '\n')
			break;
	}
	*p = '\0';
	return line;
}


/*
 * Read a character from the script, returning PEOF on end of file.
 * Nul characters in the input are silently discarded.
 */

int
pgetc(void)
{
	return pgetc_macro();
}


/*
 * Same as pgetc(), but ignores PEOA.
 */

int
pgetc2()
{
	int c;
	do {
		c = pgetc_macro();
	} while (c == PEOA);
	return c;
}


static int
preadfd(void)
{
	int nr;
	char *buf =  parsefile->buf;
	parsenextc = buf;

retry:
#ifndef SMALL
	if (parsefile->fd == 0 && el) {
		static const char *rl_cp;
		static int el_len;

		if (rl_cp == NULL)
			rl_cp = el_gets(el, &el_len);
		if (rl_cp == NULL)
			nr = 0;
		else {
			nr = el_len;
			if (nr > IBUFSIZ - 1)
				nr = IBUFSIZ - 1;
			memcpy(buf, rl_cp, nr);
			if (nr != el_len) {
				el_len -= nr;
				rl_cp += nr;
			} else
				rl_cp = 0;
		}

	} else
#endif

#ifdef HETIO
		nr = hetio_read_input(parsefile->fd);
		if (nr == -255)
#endif
		nr = read(parsefile->fd, buf, IBUFSIZ - 1);


	if (nr < 0) {
		if (errno == EINTR)
			goto retry;
		if (parsefile->fd == 0 && errno == EWOULDBLOCK) {
			int flags = fcntl(0, F_GETFL, 0);
			if (flags >= 0 && flags & O_NONBLOCK) {
				flags &=~ O_NONBLOCK;
				if (fcntl(0, F_SETFL, flags) >= 0) {
					out2str("sh: turning off NDELAY mode\n");
					goto retry;
				}
			}
		}
	}
	return nr;
}

/*
 * Refill the input buffer and return the next input character:
 *
 * 1) If a string was pushed back on the input, pop it;
 * 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
 *    from a string so we can't refill the buffer, return EOF.
 * 3) If the is more stuff in this buffer, use it else call read to fill it.
 * 4) Process input up to the next newline, deleting nul characters.
 */

int
preadbuffer(void)
{
	char *q;
	int more;
#ifndef SMALL
	int something;
#endif
	char savec;

	while (unlikely(parsefile->strpush)) {
		if (
			parsenleft == -1 && parsefile->strpush->ap &&
			parsenextc[-1] != ' ' && parsenextc[-1] != '\t'
		) {
			return PEOA;
		}
		popstring();
		if (--parsenleft >= 0)
			return (signed char)*parsenextc++;
	}
	if (unlikely(parsenleft == EOF_NLEFT || parsefile->buf == NULL))
		return PEOF;
	flushout(&output);
#ifdef FLUSHERR
	flushout(&errout);
#endif

	more = parselleft;
	if (more <= 0) {
again:
		if ((more = preadfd()) <= 0) {
			parselleft = parsenleft = EOF_NLEFT;
			return PEOF;
		}
	}

	q = parsenextc;

	/* delete nul characters */
#ifndef SMALL
	something = 0;
#endif
	for (;;) {
		int c;

		more--;
		c = *q;

		if (!c)
			memmove(q, q + 1, more);
		else {
			q++;

			if (c == '\n') {
				parsenleft = q - parsenextc - 1;
				break;
			}

#ifndef SMALL
			switch (c) {
			default:
				something = 1;
				/* fall through */
			case '\t':
			case ' ':
				break;
			}
#endif
		}

		if (more <= 0) {
			parsenleft = q - parsenextc - 1;
			if (parsenleft < 0)
				goto again;
			break;
		}
	}
	parselleft = more;

	savec = *q;
	*q = '\0';

#ifndef SMALL
	if (parsefile->fd == 0 && hist && something) {
		HistEvent he;
		INTOFF;
		history(hist, &he, whichprompt == 1? H_ENTER : H_APPEND,
		    parsenextc);
		INTON;
	}
#endif

	if (vflag) {
		out2str(parsenextc);
#ifdef FLUSHERR
		flushout(out2);
#endif
	}

	*q = savec;

	return (signed char)*parsenextc++;
}

/*
 * Undo the last call to pgetc.  Only one character may be pushed back.
 * PEOF may be pushed back.
 */

void
pungetc(void)
{
	parsenleft++;
	parsenextc--;
}

/*
 * Push a string back onto the input at this current parsefile level.
 * We handle aliases this way.
 */
void
pushstring(char *s, void *ap)
{
	struct strpush *sp;
	size_t len;

	len = strlen(s);
	INTOFF;
/*dprintf("*** calling pushstring: %s, %d\n", s, len);*/
	if (parsefile->strpush) {
		sp = ckmalloc(sizeof (struct strpush));
		sp->prev = parsefile->strpush;
		parsefile->strpush = sp;
	} else
		sp = parsefile->strpush = &(parsefile->basestrpush);
	sp->prevstring = parsenextc;
	sp->prevnleft = parsenleft;
	sp->ap = (struct alias *)ap;
	if (ap) {
		((struct alias *)ap)->flag |= ALIASINUSE;
		sp->string = s;
	}
	parsenextc = s;
	parsenleft = len;
	INTON;
}

void
popstring(void)
{
	struct strpush *sp = parsefile->strpush;

	INTOFF;
	if (sp->ap) {
		if (parsenextc[-1] == ' ' || parsenextc[-1] == '\t') {
			checkkwd |= CHKALIAS;
		}
		if (sp->string != sp->ap->val) {
			ckfree(sp->string);
		}
		sp->ap->flag &= ~ALIASINUSE;
		if (sp->ap->flag & ALIASDEAD) {
			unalias(sp->ap->name);
		}
	}
	parsenextc = sp->prevstring;
	parsenleft = sp->prevnleft;
/*dprintf("*** calling popstring: restoring to '%s'\n", parsenextc);*/
	parsefile->strpush = sp->prev;
	if (sp != &(parsefile->basestrpush))
		ckfree(sp);
	INTON;
}

/*
 * Set the input to take input from a file.  If push is set, push the
 * old input onto the stack first.
 */

int
setinputfile(const char *fname, int flags)
{
	int fd;

	INTOFF;
	if ((fd = open(fname, O_RDONLY)) < 0) {
		if (flags & INPUT_NOFILE_OK)
			goto out;
		sh_error("Can't open %s", fname);
	}
	if (fd < 10)
		fd = savefd(fd);
	setinputfd(fd, flags & INPUT_PUSH_FILE);
out:
	INTON;
	return fd;
}


/*
 * Like setinputfile, but takes an open file descriptor.  Call this with
 * interrupts off.
 */

void
setinputfd(int fd, int push)
{
	if (push) {
		pushfile();
		parsefile->buf = 0;
	}
	parsefile->fd = fd;
	if (parsefile->buf == NULL)
		parsefile->buf = ckmalloc(IBUFSIZ);
	parselleft = parsenleft = 0;
	plinno = 1;
}


/*
 * Like setinputfile, but takes input from a string.
 */

void
setinputstring(char *string)
{
	INTOFF;
	pushfile();
	parsenextc = string;
	parsenleft = strlen(string);
	parsefile->buf = NULL;
	plinno = 1;
	INTON;
}


/*
 * To handle the "." command, a stack of input files is used.  Pushfile
 * adds a new entry to the stack and popfile restores the previous level.
 */

STATIC void
pushfile(void)
{
	struct parsefile *pf;

	parsefile->nleft = parsenleft;
	parsefile->lleft = parselleft;
	parsefile->nextc = parsenextc;
	parsefile->linno = plinno;
	pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile));
	pf->prev = parsefile;
	pf->fd = -1;
	pf->strpush = NULL;
	pf->basestrpush.prev = NULL;
	parsefile = pf;
}


void
popfile(void)
{
	struct parsefile *pf = parsefile;

	INTOFF;
	if (pf->fd >= 0)
		close(pf->fd);
	if (pf->buf)
		ckfree(pf->buf);
	while (pf->strpush)
		popstring();
	parsefile = pf->prev;
	ckfree(pf);
	parsenleft = parsefile->nleft;
	parselleft = parsefile->lleft;
	parsenextc = parsefile->nextc;
	plinno = parsefile->linno;
	INTON;
}


/*
 * Return to top level.
 */

void
popallfiles(void)
{
	while (parsefile != &basepf)
		popfile();
}


/*
 * Close the file(s) that the shell is reading commands from.  Called
 * after a fork is done.
 */

void
closescript(void)
{
	popallfiles();
	if (parsefile->fd > 0) {
		close(parsefile->fd);
		parsefile->fd = 0;
	}
}
1	/*-
2	* Copyright (c) 1991, 1993
3	* The Regents of the University of California. All rights reserved.
4	* Copyright (c) 1997-2005
5	* Herbert Xu <herbert@gondor.apana.org.au>. 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. Neither the name of the University nor the names of its contributors
19	* may be used to endorse or promote products derived from this software
20	* without specific prior written permission.
21	*
22	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32	* SUCH DAMAGE.
33	*/
34
35	#include <stdio.h> /* defines BUFSIZ */
36	#include <fcntl.h>
37	#include <unistd.h>
38	#include <stdlib.h>
39	#include <string.h>
40
41	/*
42	* This file implements the input routines used by the parser.
43	*/
44
45	#include "shell.h"
46	#include "redir.h"
47	#include "syntax.h"
48	#include "input.h"
49	#include "output.h"
50	#include "options.h"
51	#include "memalloc.h"
52	#include "error.h"
53	#include "alias.h"
54	#include "parser.h"
55	#include "main.h"
56	#ifndef SMALL
57	#include "myhistedit.h"
58	#endif
59
60	#ifdef HETIO
61	#include "hetio.h"
62	#endif
63
64	#define EOF_NLEFT -99 /* value of parsenleft when EOF pushed back */
65	#define IBUFSIZ (BUFSIZ + 1)
66
67	MKINIT
68	struct 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	char string; / remember the string since it may change */
74	};
75
76	/*
77	* The parsefile structure pointed to by the global variable parsefile
78	* contains information about the current file being read.
79	*/
80
81	MKINIT
82	struct parsefile {
83	struct parsefile prev; / preceding file on stack */
84	int linno; /* current line */
85	int fd; /* file descriptor (or -1 if string) */
86	int nleft; /* number of chars left in this line */
87	int lleft; /* number of chars left in this buffer */
88	char nextc; / next char in buffer */
89	char buf; / input buffer */
90	struct strpush strpush; / for pushing strings at this level */
91	struct strpush basestrpush; /* so pushing one is fast */
92	};
93
94
95	int plinno = 1; /* input line number */
96	int parsenleft; /* copy of parsefile->nleft */
97	MKINIT int parselleft; /* copy of parsefile->lleft */
98	char parsenextc; / copy of parsefile->nextc */
99	MKINIT struct parsefile basepf; /* top level input file */
100	MKINIT char basebuf[IBUFSIZ]; /* buffer for top level input file */
101	struct parsefile parsefile = &basepf; / current input file */
102	int whichprompt; /* 1 == PS1, 2 == PS2 */
103
104	#ifndef SMALL
105	EditLine el; / cookie for editline package */
106	#endif
107
108	STATIC void pushfile(void);
109	static int preadfd(void);
110
111	#ifdef mkinit
112	INCLUDE <stdio.h>
113	INCLUDE "input.h"
114	INCLUDE "error.h"
115
116	INIT {
117	basepf.nextc = basepf.buf = basebuf;
118	}
119
120	RESET {
121	parselleft = parsenleft = 0; /* clear input buffer */
122	popallfiles();
123	}
124	#endif
125
126
127	/*
128	* Read a line from the script.
129	*/
130
131	char *
132	pfgets(char *line, int len)
133	{
134	char *p = line;
135	int nleft = len;
136	int c;
137
138	while (--nleft > 0) {
139	c = pgetc2();
140	if (c == PEOF) {
141	if (p == line)
142	return NULL;
143	break;
144	}
145	*p++ = c;
146	if (c == '\n')
147	break;
148	}
149	*p = '\0';
150	return line;
151	}
152
153
154	/*
155	* Read a character from the script, returning PEOF on end of file.
156	* Nul characters in the input are silently discarded.
157	*/
158
159	int
160	pgetc(void)
161	{
162	return pgetc_macro();
163	}
164
165
166	/*
167	* Same as pgetc(), but ignores PEOA.
168	*/
169
170	int
171	pgetc2()
172	{
173	int c;
174	do {
175	c = pgetc_macro();
176	} while (c == PEOA);
177	return c;
178	}
179
180
181	static int
182	preadfd(void)
183	{
184	int nr;
185	char *buf = parsefile->buf;
186	parsenextc = buf;
187
188	retry:
189	#ifndef SMALL
190	if (parsefile->fd == 0 && el) {
191	static const char *rl_cp;
192	static int el_len;
193
194	if (rl_cp == NULL)
195	rl_cp = el_gets(el, &el_len);
196	if (rl_cp == NULL)
197	nr = 0;
198	else {
199	nr = el_len;
200	if (nr > IBUFSIZ - 1)
201	nr = IBUFSIZ - 1;
202	memcpy(buf, rl_cp, nr);
203	if (nr != el_len) {
204	el_len -= nr;
205	rl_cp += nr;
206	} else
207	rl_cp = 0;
208	}
209
210	} else
211	#endif
212
213	#ifdef HETIO
214	nr = hetio_read_input(parsefile->fd);
215	if (nr == -255)
216	#endif
217	nr = read(parsefile->fd, buf, IBUFSIZ - 1);
218
219
220	if (nr < 0) {
221	if (errno == EINTR)
222	goto retry;
223	if (parsefile->fd == 0 && errno == EWOULDBLOCK) {
224	int flags = fcntl(0, F_GETFL, 0);
225	if (flags >= 0 && flags & O_NONBLOCK) {
226	flags &=~ O_NONBLOCK;
227	if (fcntl(0, F_SETFL, flags) >= 0) {
228	out2str("sh: turning off NDELAY mode\n");
229	goto retry;
230	}
231	}
232	}
233	}
234	return nr;
235	}
236
237	/*
238	* Refill the input buffer and return the next input character:
239	*
240	* 1) If a string was pushed back on the input, pop it;
241	* 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
242	* from a string so we can't refill the buffer, return EOF.
243	* 3) If the is more stuff in this buffer, use it else call read to fill it.
244	* 4) Process input up to the next newline, deleting nul characters.
245	*/
246
247	int
248	preadbuffer(void)
249	{
250	char *q;
251	int more;
252	#ifndef SMALL
253	int something;
254	#endif
255	char savec;
256
257	while (unlikely(parsefile->strpush)) {
258	if (
259	parsenleft == -1 && parsefile->strpush->ap &&
260	parsenextc[-1] != ' ' && parsenextc[-1] != '\t'
261	) {
262	return PEOA;
263	}
264	popstring();
265	if (--parsenleft >= 0)
266	return (signed char)*parsenextc++;
267	}
268	if (unlikely(parsenleft == EOF_NLEFT \|\| parsefile->buf == NULL))
269	return PEOF;
270	flushout(&output);
271	#ifdef FLUSHERR
272	flushout(&errout);
273	#endif
274
275	more = parselleft;
276	if (more <= 0) {
277	again:
278	if ((more = preadfd()) <= 0) {
279	parselleft = parsenleft = EOF_NLEFT;
280	return PEOF;
281	}
282	}
283
284	q = parsenextc;
285
286	/* delete nul characters */
287	#ifndef SMALL
288	something = 0;
289	#endif
290	for (;;) {
291	int c;
292
293	more--;
294	c = *q;
295
296	if (!c)
297	memmove(q, q + 1, more);
298	else {
299	q++;
300
301	if (c == '\n') {
302	parsenleft = q - parsenextc - 1;
303	break;
304	}
305
306	#ifndef SMALL
307	switch (c) {
308	default:
309	something = 1;
310	/* fall through */
311	case '\t':
312	case ' ':
313	break;
314	}
315	#endif
316	}
317
318	if (more <= 0) {
319	parsenleft = q - parsenextc - 1;
320	if (parsenleft < 0)
321	goto again;
322	break;
323	}
324	}
325	parselleft = more;
326
327	savec = *q;
328	*q = '\0';
329
330	#ifndef SMALL
331	if (parsefile->fd == 0 && hist && something) {
332	HistEvent he;
333	INTOFF;
334	history(hist, &he, whichprompt == 1? H_ENTER : H_APPEND,
335	parsenextc);
336	INTON;
337	}
338	#endif
339
340	if (vflag) {
341	out2str(parsenextc);
342	#ifdef FLUSHERR
343	flushout(out2);
344	#endif
345	}
346
347	*q = savec;
348
349	return (signed char)*parsenextc++;
350	}
351
352	/*
353	* Undo the last call to pgetc. Only one character may be pushed back.
354	* PEOF may be pushed back.
355	*/
356
357	void
358	pungetc(void)
359	{
360	parsenleft++;
361	parsenextc--;
362	}
363
364	/*
365	* Push a string back onto the input at this current parsefile level.
366	* We handle aliases this way.
367	*/
368	void
369	pushstring(char s, void ap)
370	{
371	struct strpush *sp;
372	size_t len;
373
374	len = strlen(s);
375	INTOFF;
376	/dprintf("** calling pushstring: %s, %d\n", s, len);*/
377	if (parsefile->strpush) {
378	sp = ckmalloc(sizeof (struct strpush));
379	sp->prev = parsefile->strpush;
380	parsefile->strpush = sp;
381	} else
382	sp = parsefile->strpush = &(parsefile->basestrpush);
383	sp->prevstring = parsenextc;
384	sp->prevnleft = parsenleft;
385	sp->ap = (struct alias *)ap;
386	if (ap) {
387	((struct alias *)ap)->flag \|= ALIASINUSE;
388	sp->string = s;
389	}
390	parsenextc = s;
391	parsenleft = len;
392	INTON;
393	}
394
395	void
396	popstring(void)
397	{
398	struct strpush *sp = parsefile->strpush;
399
400	INTOFF;
401	if (sp->ap) {
402	if (parsenextc[-1] == ' ' \|\| parsenextc[-1] == '\t') {
403	checkkwd \|= CHKALIAS;
404	}
405	if (sp->string != sp->ap->val) {
406	ckfree(sp->string);
407	}
408	sp->ap->flag &= ~ALIASINUSE;
409	if (sp->ap->flag & ALIASDEAD) {
410	unalias(sp->ap->name);
411	}
412	}
413	parsenextc = sp->prevstring;
414	parsenleft = sp->prevnleft;
415	/dprintf("** calling popstring: restoring to '%s'\n", parsenextc);*/
416	parsefile->strpush = sp->prev;
417	if (sp != &(parsefile->basestrpush))
418	ckfree(sp);
419	INTON;
420	}
421
422	/*
423	* Set the input to take input from a file. If push is set, push the
424	* old input onto the stack first.
425	*/
426
427	int
428	setinputfile(const char *fname, int flags)
429	{
430	int fd;
431
432	INTOFF;
433	if ((fd = open(fname, O_RDONLY)) < 0) {
434	if (flags & INPUT_NOFILE_OK)
435	goto out;
436	sh_error("Can't open %s", fname);
437	}
438	if (fd < 10)
439	fd = savefd(fd);
440	setinputfd(fd, flags & INPUT_PUSH_FILE);
441	out:
442	INTON;
443	return fd;
444	}
445
446
447	/*
448	* Like setinputfile, but takes an open file descriptor. Call this with
449	* interrupts off.
450	*/
451
452	void
453	setinputfd(int fd, int push)
454	{
455	if (push) {
456	pushfile();
457	parsefile->buf = 0;
458	}
459	parsefile->fd = fd;
460	if (parsefile->buf == NULL)
461	parsefile->buf = ckmalloc(IBUFSIZ);
462	parselleft = parsenleft = 0;
463	plinno = 1;
464	}
465
466
467	/*
468	* Like setinputfile, but takes input from a string.
469	*/
470
471	void
472	setinputstring(char *string)
473	{
474	INTOFF;
475	pushfile();
476	parsenextc = string;
477	parsenleft = strlen(string);
478	parsefile->buf = NULL;
479	plinno = 1;
480	INTON;
481	}
482
483
484
485	/*
486	* To handle the "." command, a stack of input files is used. Pushfile
487	* adds a new entry to the stack and popfile restores the previous level.
488	*/
489
490	STATIC void
491	pushfile(void)
492	{
493	struct parsefile *pf;
494
495	parsefile->nleft = parsenleft;
496	parsefile->lleft = parselleft;
497	parsefile->nextc = parsenextc;
498	parsefile->linno = plinno;
499	pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile));
500	pf->prev = parsefile;
501	pf->fd = -1;
502	pf->strpush = NULL;
503	pf->basestrpush.prev = NULL;
504	parsefile = pf;
505	}
506
507
508	void
509	popfile(void)
510	{
511	struct parsefile *pf = parsefile;
512
513	INTOFF;
514	if (pf->fd >= 0)
515	close(pf->fd);
516	if (pf->buf)
517	ckfree(pf->buf);
518	while (pf->strpush)
519	popstring();
520	parsefile = pf->prev;
521	ckfree(pf);
522	parsenleft = parsefile->nleft;
523	parselleft = parsefile->lleft;
524	parsenextc = parsefile->nextc;
525	plinno = parsefile->linno;
526	INTON;
527	}
528
529
530	/*
531	* Return to top level.
532	*/
533
534	void
535	popallfiles(void)
536	{
537	while (parsefile != &basepf)
538	popfile();
539	}
540
541
542
543	/*
544	* Close the file(s) that the shell is reading commands from. Called
545	* after a fork is done.
546	*/
547
548	void
549	closescript(void)
550	{
551	popallfiles();
552	if (parsefile->fd > 0) {
553	close(parsefile->fd);
554	parsefile->fd = 0;
555	}
556	}