summaryrefslogtreecommitdiffstats
path: root/bin/sh/input.c
blob: 05cc1ebe606f6436bcd84ca754a92ca2b3a039b4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
/*-
 * Copyright (c) 1991, 1993
 *	The Regents of the University of California.  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.
 * 4. 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.
 */

#ifndef lint
#if 0
static char sccsid[] = "@(#)input.c	8.3 (Berkeley) 6/9/95";
#endif
#endif /* not lint */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <stdio.h>	/* defines BUFSIZ */
#include <fcntl.h>
#include <errno.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 "myhistedit.h"
#include "trap.h"

#define EOF_NLEFT -99		/* value of parsenleft when EOF pushed back */

struct strpush {
	struct strpush *prev;	/* preceding string on stack */
	const char *prevstring;
	int prevnleft;
	int prevlleft;
	struct alias *ap;	/* if push was associated with an alias */
};

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

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 lines left in this buffer */
	const 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 */
static int parselleft;		/* copy of parsefile->lleft */
const char *parsenextc;		/* copy of parsefile->nextc */
static char basebuf[BUFSIZ + 1];/* buffer for top level input file */
static struct parsefile basepf = {	/* top level input file */
	.nextc = basebuf,
	.buf = basebuf
};
static struct parsefile *parsefile = &basepf;	/* current input file */
int whichprompt;		/* 1 == PS1, 2 == PS2 */

EditLine *el;			/* cookie for editline package */

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

void
resetinput(void)
{
	popallfiles();
	parselleft = parsenleft = 0;	/* clear input buffer */
}


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

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

	while (--nleft > 0) {
		c = pgetc_macro();
		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();
}


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

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

		if (rl_cp == NULL) {
			el_resize(el);
			rl_cp = el_gets(el, &el_len);
		}
		if (rl_cp == NULL)
			nr = el_len == 0 ? 0 : -1;
		else {
			nr = el_len;
			if (nr > BUFSIZ)
				nr = BUFSIZ;
			memcpy(parsefile->buf, rl_cp, nr);
			if (nr != el_len) {
				el_len -= nr;
				rl_cp += nr;
			} else
				rl_cp = NULL;
		}
	} else
#endif
		nr = read(parsefile->fd, parsefile->buf, BUFSIZ);

	if (nr <= 0) {
                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) {
						out2fmt_flush("sh: turning off NDELAY mode\n");
                                                goto retry;
                                        }
                                }
                        }
                }
                nr = -1;
	}
	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 there is more 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 *p, *q;
	int more;
	char savec;

	while (parsefile->strpush) {
		/*
		 * Add a space to the end of an alias to ensure that the
		 * alias remains in use while parsing its last word.
		 * This avoids alias recursions.
		 */
		if (parsenleft == -1 && parsefile->strpush->ap != NULL)
			return ' ';
		popstring();
		if (--parsenleft >= 0)
			return (*parsenextc++);
	}
	if (parsenleft == EOF_NLEFT || parsefile->buf == NULL)
		return PEOF;
	flushout(&output);
	flushout(&errout);

again:
	if (parselleft <= 0) {
		if ((parselleft = preadfd()) == -1) {
			parselleft = parsenleft = EOF_NLEFT;
			return PEOF;
		}
	}

	q = p = parsefile->buf + (parsenextc - parsefile->buf);

	/* delete nul characters */
	for (more = 1; more;) {
		switch (*p) {
		case '\0':
			p++;	/* Skip nul */
			goto check;

		case '\n':
			parsenleft = q - parsenextc;
			more = 0; /* Stop processing here */
			break;

		default:
			break;
		}

		*q++ = *p++;
check:
		if (--parselleft <= 0) {
			parsenleft = q - parsenextc - 1;
			if (parsenleft < 0)
				goto again;
			*q = '\0';
			more = 0;
		}
	}

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

#ifndef NO_HISTORY
	if (parsefile->fd == 0 && hist &&
	    parsenextc[strspn(parsenextc, " \t\n")] != '\0') {
		HistEvent he;
		INTOFF;
		history(hist, &he, whichprompt == 1 ? H_ENTER : H_ADD,
		    parsenextc);
		INTON;
	}
#endif

	if (vflag) {
		out2str(parsenextc);
		flushout(out2);
	}

	*q = savec;

	return *parsenextc++;
}

/*
 * Returns if we are certain we are at EOF. Does not cause any more input
 * to be read from the outside world.
 */

int
preadateof(void)
{
	if (parsenleft > 0)
		return 0;
	if (parsefile->strpush)
		return 0;
	if (parsenleft == EOF_NLEFT || parsefile->buf == NULL)
		return 1;
	return 0;
}

/*
 * 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, int len, struct alias *ap)
{
	struct strpush *sp;

	INTOFF;
/*out2fmt_flush("*** 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->prevlleft = parselleft;
	sp->ap = ap;
	if (ap)
		ap->flag |= ALIASINUSE;
	parsenextc = s;
	parsenleft = len;
	INTON;
}

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

	INTOFF;
	if (sp->ap) {
		if (parsenextc != sp->ap->val &&
		    (parsenextc[-1] == ' ' || parsenextc[-1] == '\t'))
			forcealias();
		sp->ap->flag &= ~ALIASINUSE;
	}
	parsenextc = sp->prevstring;
	parsenleft = sp->prevnleft;
	parselleft = sp->prevlleft;
/*out2fmt_flush("*** 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.
 */

void
setinputfile(const char *fname, int push)
{
	int fd;
	int fd2;

	INTOFF;
	if ((fd = open(fname, O_RDONLY | O_CLOEXEC)) < 0)
		error("cannot open %s: %s", fname, strerror(errno));
	if (fd < 10) {
		fd2 = fcntl(fd, F_DUPFD_CLOEXEC, 10);
		close(fd);
		if (fd2 < 0)
			error("Out of file descriptors");
		fd = fd2;
	}
	setinputfd(fd, push);
	INTON;
}


/*
 * Like setinputfile, but takes an open file descriptor (which should have
 * its FD_CLOEXEC flag already set).  Call this with interrupts off.
 */

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


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

void
setinputstring(const char *string, int push)
{
	INTOFF;
	if (push)
		pushfile();
	parsenextc = string;
	parselleft = 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 current file (to go back to it later using popfilesupto()).
 */

struct parsefile *
getcurrentfile(void)
{
	return parsefile;
}


/*
 * Pop files until the given file is on top again. Useful for regular
 * builtins that read shell commands from files or strings.
 * If the given file is not an active file, an error is raised.
 */

void
popfilesupto(struct parsefile *file)
{
	while (parsefile != file && parsefile != &basepf)
		popfile();
	if (parsefile != file)
		error("popfilesupto() misused");
}

/*
 * 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;
	}
}
OpenPOWER on IntegriCloud