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"
#include "var.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);
static void setinputfd(int fd, int push);

#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 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, fd);
	setinputfd(fd, flags & INPUT_PUSH_FILE);
out:
	INTON;
	return fd;
}


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

static 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;
	}
}


int lineno_inc(void)
{
	int lineno = plinno++;

	setvarint("LINENO", lineno, 0);
	return lineno;
}
1	niro	532	/*-
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	niro	1122	#include "var.h"
57	niro	532	#ifndef SMALL
58			#include "myhistedit.h"
59			#endif
60
61			#ifdef HETIO
62			#include "hetio.h"
63			#endif
64
65			#define EOF_NLEFT -99 /* value of parsenleft when EOF pushed back */
66			#define IBUFSIZ (BUFSIZ + 1)
67
68			MKINIT
69			struct strpush {
70			struct strpush prev; / preceding string on stack */
71			char *prevstring;
72			int prevnleft;
73			struct alias ap; / if push was associated with an alias */
74			char string; / remember the string since it may change */
75			};
76
77			/*
78			* The parsefile structure pointed to by the global variable parsefile
79			* contains information about the current file being read.
80			*/
81
82			MKINIT
83			struct parsefile {
84			struct parsefile prev; / preceding file on stack */
85			int linno; /* current line */
86			int fd; /* file descriptor (or -1 if string) */
87			int nleft; /* number of chars left in this line */
88			int lleft; /* number of chars left in this buffer */
89			char nextc; / next char in buffer */
90			char buf; / input buffer */
91			struct strpush strpush; / for pushing strings at this level */
92			struct strpush basestrpush; /* so pushing one is fast */
93			};
94
95
96			int plinno = 1; /* input line number */
97			int parsenleft; /* copy of parsefile->nleft */
98			MKINIT int parselleft; /* copy of parsefile->lleft */
99			char parsenextc; / copy of parsefile->nextc */
100			MKINIT struct parsefile basepf; /* top level input file */
101			MKINIT char basebuf[IBUFSIZ]; /* buffer for top level input file */
102			struct parsefile parsefile = &basepf; / current input file */
103			int whichprompt; /* 1 == PS1, 2 == PS2 */
104
105			#ifndef SMALL
106			EditLine el; / cookie for editline package */
107			#endif
108
109			STATIC void pushfile(void);
110			static int preadfd(void);
111	niro	1122	static void setinputfd(int fd, int push);
112	niro	532
113			#ifdef mkinit
114			INCLUDE <stdio.h>
115			INCLUDE "input.h"
116			INCLUDE "error.h"
117
118			INIT {
119			basepf.nextc = basepf.buf = basebuf;
120			}
121
122			RESET {
123			parselleft = parsenleft = 0; /* clear input buffer */
124			popallfiles();
125			}
126			#endif
127
128
129			/*
130			* Read a character from the script, returning PEOF on end of file.
131			* Nul characters in the input are silently discarded.
132			*/
133
134			int
135			pgetc(void)
136			{
137			return pgetc_macro();
138			}
139
140
141			/*
142			* Same as pgetc(), but ignores PEOA.
143			*/
144
145			int
146			pgetc2()
147			{
148			int c;
149			do {
150			c = pgetc_macro();
151			} while (c == PEOA);
152			return c;
153			}
154
155
156			static int
157			preadfd(void)
158			{
159			int nr;
160			char *buf = parsefile->buf;
161			parsenextc = buf;
162
163			retry:
164			#ifndef SMALL
165			if (parsefile->fd == 0 && el) {
166			static const char *rl_cp;
167			static int el_len;
168
169			if (rl_cp == NULL)
170			rl_cp = el_gets(el, &el_len);
171			if (rl_cp == NULL)
172			nr = 0;
173			else {
174			nr = el_len;
175			if (nr > IBUFSIZ - 1)
176			nr = IBUFSIZ - 1;
177			memcpy(buf, rl_cp, nr);
178			if (nr != el_len) {
179			el_len -= nr;
180			rl_cp += nr;
181			} else
182			rl_cp = 0;
183			}
184
185			} else
186			#endif
187
188			#ifdef HETIO
189			nr = hetio_read_input(parsefile->fd);
190			if (nr == -255)
191			#endif
192			nr = read(parsefile->fd, buf, IBUFSIZ - 1);
193
194
195			if (nr < 0) {
196			if (errno == EINTR)
197			goto retry;
198			if (parsefile->fd == 0 && errno == EWOULDBLOCK) {
199			int flags = fcntl(0, F_GETFL, 0);
200			if (flags >= 0 && flags & O_NONBLOCK) {
201			flags &=~ O_NONBLOCK;
202			if (fcntl(0, F_SETFL, flags) >= 0) {
203			out2str("sh: turning off NDELAY mode\n");
204			goto retry;
205			}
206			}
207			}
208			}
209			return nr;
210			}
211
212			/*
213			* Refill the input buffer and return the next input character:
214			*
215			* 1) If a string was pushed back on the input, pop it;
216			* 2) If an EOF was pushed back (parsenleft == EOF_NLEFT) or we are reading
217			* from a string so we can't refill the buffer, return EOF.
218			* 3) If the is more stuff in this buffer, use it else call read to fill it.
219			* 4) Process input up to the next newline, deleting nul characters.
220			*/
221
222			int
223			preadbuffer(void)
224			{
225			char *q;
226			int more;
227			#ifndef SMALL
228			int something;
229			#endif
230			char savec;
231
232			while (unlikely(parsefile->strpush)) {
233			if (
234			parsenleft == -1 && parsefile->strpush->ap &&
235			parsenextc[-1] != ' ' && parsenextc[-1] != '\t'
236			) {
237			return PEOA;
238			}
239			popstring();
240			if (--parsenleft >= 0)
241			return (signed char)*parsenextc++;
242			}
243			if (unlikely(parsenleft == EOF_NLEFT \|\| parsefile->buf == NULL))
244			return PEOF;
245			flushout(&output);
246			#ifdef FLUSHERR
247			flushout(&errout);
248			#endif
249
250			more = parselleft;
251			if (more <= 0) {
252			again:
253			if ((more = preadfd()) <= 0) {
254			parselleft = parsenleft = EOF_NLEFT;
255			return PEOF;
256			}
257			}
258
259			q = parsenextc;
260
261			/* delete nul characters */
262			#ifndef SMALL
263			something = 0;
264			#endif
265			for (;;) {
266			int c;
267
268			more--;
269			c = *q;
270
271			if (!c)
272			memmove(q, q + 1, more);
273			else {
274			q++;
275
276			if (c == '\n') {
277			parsenleft = q - parsenextc - 1;
278			break;
279			}
280
281			#ifndef SMALL
282			switch (c) {
283			default:
284			something = 1;
285			/* fall through */
286			case '\t':
287			case ' ':
288			break;
289			}
290			#endif
291			}
292
293			if (more <= 0) {
294			parsenleft = q - parsenextc - 1;
295			if (parsenleft < 0)
296			goto again;
297			break;
298			}
299			}
300			parselleft = more;
301
302			savec = *q;
303			*q = '\0';
304
305			#ifndef SMALL
306			if (parsefile->fd == 0 && hist && something) {
307			HistEvent he;
308			INTOFF;
309			history(hist, &he, whichprompt == 1? H_ENTER : H_APPEND,
310			parsenextc);
311			INTON;
312			}
313			#endif
314
315			if (vflag) {
316			out2str(parsenextc);
317			#ifdef FLUSHERR
318			flushout(out2);
319			#endif
320			}
321
322			*q = savec;
323
324			return (signed char)*parsenextc++;
325			}
326
327			/*
328			* Undo the last call to pgetc. Only one character may be pushed back.
329			* PEOF may be pushed back.
330			*/
331
332			void
333			pungetc(void)
334			{
335			parsenleft++;
336			parsenextc--;
337			}
338
339			/*
340			* Push a string back onto the input at this current parsefile level.
341			* We handle aliases this way.
342			*/
343			void
344			pushstring(char s, void ap)
345			{
346			struct strpush *sp;
347			size_t len;
348
349			len = strlen(s);
350			INTOFF;
351			/dprintf("** calling pushstring: %s, %d\n", s, len);*/
352			if (parsefile->strpush) {
353			sp = ckmalloc(sizeof (struct strpush));
354			sp->prev = parsefile->strpush;
355			parsefile->strpush = sp;
356			} else
357			sp = parsefile->strpush = &(parsefile->basestrpush);
358			sp->prevstring = parsenextc;
359			sp->prevnleft = parsenleft;
360			sp->ap = (struct alias *)ap;
361			if (ap) {
362			((struct alias *)ap)->flag \|= ALIASINUSE;
363			sp->string = s;
364			}
365			parsenextc = s;
366			parsenleft = len;
367			INTON;
368			}
369
370			void
371			popstring(void)
372			{
373			struct strpush *sp = parsefile->strpush;
374
375			INTOFF;
376			if (sp->ap) {
377			if (parsenextc[-1] == ' ' \|\| parsenextc[-1] == '\t') {
378			checkkwd \|= CHKALIAS;
379			}
380			if (sp->string != sp->ap->val) {
381			ckfree(sp->string);
382			}
383			sp->ap->flag &= ~ALIASINUSE;
384			if (sp->ap->flag & ALIASDEAD) {
385			unalias(sp->ap->name);
386			}
387			}
388			parsenextc = sp->prevstring;
389			parsenleft = sp->prevnleft;
390			/dprintf("** calling popstring: restoring to '%s'\n", parsenextc);*/
391			parsefile->strpush = sp->prev;
392			if (sp != &(parsefile->basestrpush))
393			ckfree(sp);
394			INTON;
395			}
396
397			/*
398			* Set the input to take input from a file. If push is set, push the
399			* old input onto the stack first.
400			*/
401
402			int
403			setinputfile(const char *fname, int flags)
404			{
405			int fd;
406
407			INTOFF;
408			if ((fd = open(fname, O_RDONLY)) < 0) {
409			if (flags & INPUT_NOFILE_OK)
410			goto out;
411			sh_error("Can't open %s", fname);
412			}
413	niro	815	if (fd < 10)
414	niro	1122	fd = savefd(fd, fd);
415	niro	532	setinputfd(fd, flags & INPUT_PUSH_FILE);
416			out:
417			INTON;
418			return fd;
419			}
420
421
422			/*
423			* Like setinputfile, but takes an open file descriptor. Call this with
424			* interrupts off.
425			*/
426
427	niro	1122	static void
428	niro	532	setinputfd(int fd, int push)
429			{
430			if (push) {
431			pushfile();
432			parsefile->buf = 0;
433			}
434			parsefile->fd = fd;
435			if (parsefile->buf == NULL)
436			parsefile->buf = ckmalloc(IBUFSIZ);
437			parselleft = parsenleft = 0;
438			plinno = 1;
439			}
440
441
442			/*
443			* Like setinputfile, but takes input from a string.
444			*/
445
446			void
447			setinputstring(char *string)
448			{
449			INTOFF;
450			pushfile();
451			parsenextc = string;
452			parsenleft = strlen(string);
453			parsefile->buf = NULL;
454			plinno = 1;
455			INTON;
456			}
457
458
459
460			/*
461			* To handle the "." command, a stack of input files is used. Pushfile
462			* adds a new entry to the stack and popfile restores the previous level.
463			*/
464
465			STATIC void
466			pushfile(void)
467			{
468			struct parsefile *pf;
469
470			parsefile->nleft = parsenleft;
471			parsefile->lleft = parselleft;
472			parsefile->nextc = parsenextc;
473			parsefile->linno = plinno;
474			pf = (struct parsefile *)ckmalloc(sizeof (struct parsefile));
475			pf->prev = parsefile;
476			pf->fd = -1;
477			pf->strpush = NULL;
478			pf->basestrpush.prev = NULL;
479			parsefile = pf;
480			}
481
482
483			void
484			popfile(void)
485			{
486			struct parsefile *pf = parsefile;
487
488			INTOFF;
489			if (pf->fd >= 0)
490			close(pf->fd);
491			if (pf->buf)
492			ckfree(pf->buf);
493			while (pf->strpush)
494			popstring();
495			parsefile = pf->prev;
496			ckfree(pf);
497			parsenleft = parsefile->nleft;
498			parselleft = parsefile->lleft;
499			parsenextc = parsefile->nextc;
500			plinno = parsefile->linno;
501			INTON;
502			}
503
504
505			/*
506			* Return to top level.
507			*/
508
509			void
510			popallfiles(void)
511			{
512			while (parsefile != &basepf)
513			popfile();
514			}
515
516
517
518			/*
519			* Close the file(s) that the shell is reading commands from. Called
520			* after a fork is done.
521			*/
522
523			void
524			closescript(void)
525			{
526			popallfiles();
527			if (parsefile->fd > 0) {
528			close(parsefile->fd);
529			parsefile->fd = 0;
530			}
531			}
532	niro	1122
533
534			int lineno_inc(void)
535			{
536			int lineno = plinno++;
537
538			setvarint("LINENO", lineno, 0);
539			return lineno;
540			}