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	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			#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	niro	815	if (fd < 10)
439			fd = savefd(fd);
440	niro	532	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			}