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read.c revision 1.105 
      1 /*	$NetBSD: read.c,v 1.105 2018/11/25 16:21:04 christos Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1992, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software contributed to Berkeley by
      8  * Christos Zoulas of Cornell University.
      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 "config.h"
     36 #if !defined(lint) && !defined(SCCSID)
     37 #if 0
     38 static char sccsid[] = "@(#)read.c	8.1 (Berkeley) 6/4/93";
     39 #else
     40 __RCSID("$NetBSD: read.c,v 1.105 2018/11/25 16:21:04 christos Exp $");
     41 #endif
     42 #endif /* not lint && not SCCSID */
     43 
     44 /*
     45  * read.c: Terminal read functions
     46  */
     47 #include <ctype.h>
     48 #include <errno.h>
     49 #include <fcntl.h>
     50 #include <limits.h>
     51 #include <stdlib.h>
     52 #include <string.h>
     53 #include <unistd.h>
     54 
     55 #include "el.h"
     56 #include "fcns.h"
     57 #include "read.h"
     58 
     59 #define	EL_MAXMACRO	10
     60 
     61 struct macros {
     62 	wchar_t	**macro;
     63 	int	  level;
     64 	int	  offset;
     65 };
     66 
     67 struct el_read_t {
     68 	struct macros	 macros;
     69 	el_rfunc_t	 read_char;	/* Function to read a character. */
     70 	int		 read_errno;
     71 };
     72 
     73 static int	read__fixio(int, int);
     74 static int	read_char(EditLine *, wchar_t *);
     75 static int	read_getcmd(EditLine *, el_action_t *, wchar_t *);
     76 static void	read_clearmacros(struct macros *);
     77 static void	read_pop(struct macros *);
     78 static const wchar_t *noedit_wgets(EditLine *, int *);
     79 
     80 /* read_init():
     81  *	Initialize the read stuff
     82  */
     83 libedit_private int
     84 read_init(EditLine *el)
     85 {
     86 	struct macros *ma;
     87 
     88 	if ((el->el_read = el_malloc(sizeof(*el->el_read))) == NULL)
     89 		return -1;
     90 
     91 	ma = &el->el_read->macros;
     92 	if ((ma->macro = el_malloc(EL_MAXMACRO *
     93 	    sizeof(*ma->macro))) == NULL) {
     94 		free(el->el_read);
     95 		return -1;
     96 	}
     97 	ma->level = -1;
     98 	ma->offset = 0;
     99 
    100 	/* builtin read_char */
    101 	el->el_read->read_char = read_char;
    102 	return 0;
    103 }
    104 
    105 /* el_read_end():
    106  *	Free the data structures used by the read stuff.
    107  */
    108 libedit_private void
    109 read_end(struct el_read_t *el_read)
    110 {
    111 	read_clearmacros(&el_read->macros);
    112 	el_free(el_read->macros.macro);
    113 	el_read->macros.macro = NULL;
    114 	el_free(el_read);
    115 }
    116 
    117 /* el_read_setfn():
    118  *	Set the read char function to the one provided.
    119  *	If it is set to EL_BUILTIN_GETCFN, then reset to the builtin one.
    120  */
    121 libedit_private int
    122 el_read_setfn(struct el_read_t *el_read, el_rfunc_t rc)
    123 {
    124 	el_read->read_char = (rc == EL_BUILTIN_GETCFN) ? read_char : rc;
    125 	return 0;
    126 }
    127 
    128 
    129 /* el_read_getfn():
    130  *	return the current read char function, or EL_BUILTIN_GETCFN
    131  *	if it is the default one
    132  */
    133 libedit_private el_rfunc_t
    134 el_read_getfn(struct el_read_t *el_read)
    135 {
    136        return el_read->read_char == read_char ?
    137 	    EL_BUILTIN_GETCFN : el_read->read_char;
    138 }
    139 
    140 
    141 /* read__fixio():
    142  *	Try to recover from a read error
    143  */
    144 /* ARGSUSED */
    145 static int
    146 read__fixio(int fd __attribute__((__unused__)), int e)
    147 {
    148 
    149 	switch (e) {
    150 	case -1:		/* Make sure that the code is reachable */
    151 
    152 #ifdef EWOULDBLOCK
    153 	case EWOULDBLOCK:
    154 #ifndef TRY_AGAIN
    155 #define TRY_AGAIN
    156 #endif
    157 #endif /* EWOULDBLOCK */
    158 
    159 #if defined(POSIX) && defined(EAGAIN)
    160 #if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
    161 	case EAGAIN:
    162 #ifndef TRY_AGAIN
    163 #define TRY_AGAIN
    164 #endif
    165 #endif /* EWOULDBLOCK && EWOULDBLOCK != EAGAIN */
    166 #endif /* POSIX && EAGAIN */
    167 
    168 		e = 0;
    169 #ifdef TRY_AGAIN
    170 #if defined(F_SETFL) && defined(O_NDELAY)
    171 		if ((e = fcntl(fd, F_GETFL, 0)) == -1)
    172 			return -1;
    173 
    174 		if (fcntl(fd, F_SETFL, e & ~O_NDELAY) == -1)
    175 			return -1;
    176 		else
    177 			e = 1;
    178 #endif /* F_SETFL && O_NDELAY */
    179 
    180 #ifdef FIONBIO
    181 		{
    182 			int zero = 0;
    183 
    184 			if (ioctl(fd, FIONBIO, &zero) == -1)
    185 				return -1;
    186 			else
    187 				e = 1;
    188 		}
    189 #endif /* FIONBIO */
    190 
    191 #endif /* TRY_AGAIN */
    192 		return e ? 0 : -1;
    193 
    194 	case EINTR:
    195 		return 0;
    196 
    197 	default:
    198 		return -1;
    199 	}
    200 }
    201 
    202 
    203 /* el_push():
    204  *	Push a macro
    205  */
    206 void
    207 el_wpush(EditLine *el, const wchar_t *str)
    208 {
    209 	struct macros *ma = &el->el_read->macros;
    210 
    211 	if (str != NULL && ma->level + 1 < EL_MAXMACRO) {
    212 		ma->level++;
    213 		if ((ma->macro[ma->level] = wcsdup(str)) != NULL)
    214 			return;
    215 		ma->level--;
    216 	}
    217 	terminal_beep(el);
    218 	terminal__flush(el);
    219 }
    220 
    221 
    222 /* read_getcmd():
    223  *	Get next command from the input stream,
    224  *	return 0 on success or -1 on EOF or error.
    225  *	Character values > 255 are not looked up in the map, but inserted.
    226  */
    227 static int
    228 read_getcmd(EditLine *el, el_action_t *cmdnum, wchar_t *ch)
    229 {
    230 	static const wchar_t meta = (wchar_t)0x80;
    231 	el_action_t cmd;
    232 
    233 	do {
    234 		if (el_wgetc(el, ch) != 1)
    235 			return -1;
    236 
    237 #ifdef	KANJI
    238 		if ((*ch & meta)) {
    239 			el->el_state.metanext = 0;
    240 			cmd = CcViMap[' '];
    241 			break;
    242 		} else
    243 #endif /* KANJI */
    244 
    245 		if (el->el_state.metanext) {
    246 			el->el_state.metanext = 0;
    247 			*ch |= meta;
    248 		}
    249 		if (*ch >= N_KEYS)
    250 			cmd = ED_INSERT;
    251 		else
    252 			cmd = el->el_map.current[(unsigned char) *ch];
    253 		if (cmd == ED_SEQUENCE_LEAD_IN) {
    254 			keymacro_value_t val;
    255 			switch (keymacro_get(el, ch, &val)) {
    256 			case XK_CMD:
    257 				cmd = val.cmd;
    258 				break;
    259 			case XK_STR:
    260 				el_wpush(el, val.str);
    261 				break;
    262 			case XK_NOD:
    263 				return -1;
    264 			default:
    265 				EL_ABORT((el->el_errfile, "Bad XK_ type \n"));
    266 				break;
    267 			}
    268 		}
    269 	} while (cmd == ED_SEQUENCE_LEAD_IN);
    270 	*cmdnum = cmd;
    271 	return 0;
    272 }
    273 
    274 /* read_char():
    275  *	Read a character from the tty.
    276  */
    277 static int
    278 read_char(EditLine *el, wchar_t *cp)
    279 {
    280 	ssize_t num_read;
    281 	int tried = 0;
    282 	char cbuf[MB_LEN_MAX];
    283 	size_t cbp = 0;
    284 	int save_errno = errno;
    285 
    286  again:
    287 	el->el_signal->sig_no = 0;
    288 	while ((num_read = read(el->el_infd, cbuf + cbp, (size_t)1)) == -1) {
    289 		int e = errno;
    290 		switch (el->el_signal->sig_no) {
    291 		case SIGCONT:
    292 			el_wset(el, EL_REFRESH);
    293 			/*FALLTHROUGH*/
    294 		case SIGWINCH:
    295 			sig_set(el);
    296 			goto again;
    297 		default:
    298 			break;
    299 		}
    300 		if (!tried && read__fixio(el->el_infd, e) == 0) {
    301 			errno = save_errno;
    302 			tried = 1;
    303 		} else {
    304 			errno = e;
    305 			*cp = L'\0';
    306 			return -1;
    307 		}
    308 	}
    309 
    310 	/* Test for EOF */
    311 	if (num_read == 0) {
    312 		*cp = L'\0';
    313 		return 0;
    314 	}
    315 
    316 	for (;;) {
    317 		mbstate_t mbs;
    318 
    319 		++cbp;
    320 		/* This only works because UTF8 is stateless. */
    321 		memset(&mbs, 0, sizeof(mbs));
    322 		switch (mbrtowc(cp, cbuf, cbp, &mbs)) {
    323 		case (size_t)-1:
    324 			if (cbp > 1) {
    325 				/*
    326 				 * Invalid sequence, discard all bytes
    327 				 * except the last one.
    328 				 */
    329 				cbuf[0] = cbuf[cbp - 1];
    330 				cbp = 0;
    331 				break;
    332 			} else {
    333 				/* Invalid byte, discard it. */
    334 				cbp = 0;
    335 				goto again;
    336 			}
    337 		case (size_t)-2:
    338 			if (cbp >= MB_LEN_MAX) {
    339 				errno = EILSEQ;
    340 				*cp = L'\0';
    341 				return -1;
    342 			}
    343 			/* Incomplete sequence, read another byte. */
    344 			goto again;
    345 		default:
    346 			/* Valid character, process it. */
    347 			return 1;
    348 		}
    349 	}
    350 }
    351 
    352 /* read_pop():
    353  *	Pop a macro from the stack
    354  */
    355 static void
    356 read_pop(struct macros *ma)
    357 {
    358 	int i;
    359 
    360 	el_free(ma->macro[0]);
    361 	for (i = 0; i < ma->level; i++)
    362 		ma->macro[i] = ma->macro[i + 1];
    363 	ma->level--;
    364 	ma->offset = 0;
    365 }
    366 
    367 static void
    368 read_clearmacros(struct macros *ma)
    369 {
    370 	while (ma->level >= 0)
    371 		el_free(ma->macro[ma->level--]);
    372 	ma->offset = 0;
    373 }
    374 
    375 /* el_wgetc():
    376  *	Read a wide character
    377  */
    378 int
    379 el_wgetc(EditLine *el, wchar_t *cp)
    380 {
    381 	struct macros *ma = &el->el_read->macros;
    382 	int num_read;
    383 
    384 	terminal__flush(el);
    385 	for (;;) {
    386 		if (ma->level < 0)
    387 			break;
    388 
    389 		if (ma->macro[0][ma->offset] == '\0') {
    390 			read_pop(ma);
    391 			continue;
    392 		}
    393 
    394 		*cp = ma->macro[0][ma->offset++];
    395 
    396 		if (ma->macro[0][ma->offset] == '\0') {
    397 			/* Needed for QuoteMode On */
    398 			read_pop(ma);
    399 		}
    400 
    401 		return 1;
    402 	}
    403 
    404 	if (tty_rawmode(el) < 0)/* make sure the tty is set up correctly */
    405 		return 0;
    406 
    407 	num_read = (*el->el_read->read_char)(el, cp);
    408 
    409 	/*
    410 	 * Remember the original reason of a read failure
    411 	 * such that el_wgets() can restore it after doing
    412 	 * various cleanup operation that might change errno.
    413 	 */
    414 	if (num_read < 0)
    415 		el->el_read->read_errno = errno;
    416 
    417 	return num_read;
    418 }
    419 
    420 libedit_private void
    421 read_prepare(EditLine *el)
    422 {
    423 	if (el->el_flags & HANDLE_SIGNALS)
    424 		sig_set(el);
    425 	if (el->el_flags & NO_TTY)
    426 		return;
    427 	if ((el->el_flags & (UNBUFFERED|EDIT_DISABLED)) == UNBUFFERED)
    428 		tty_rawmode(el);
    429 
    430 	/* This is relatively cheap, and things go terribly wrong if
    431 	   we have the wrong size. */
    432 	el_resize(el);
    433 	re_clear_display(el);	/* reset the display stuff */
    434 	ch_reset(el);
    435 	re_refresh(el);		/* print the prompt */
    436 
    437 	if (el->el_flags & UNBUFFERED)
    438 		terminal__flush(el);
    439 }
    440 
    441 libedit_private void
    442 read_finish(EditLine *el)
    443 {
    444 	if ((el->el_flags & UNBUFFERED) == 0)
    445 		(void) tty_cookedmode(el);
    446 	if (el->el_flags & HANDLE_SIGNALS)
    447 		sig_clr(el);
    448 }
    449 
    450 static const wchar_t *
    451 noedit_wgets(EditLine *el, int *nread)
    452 {
    453 	el_line_t	*lp = &el->el_line;
    454 	int		 num;
    455 
    456 	while ((num = (*el->el_read->read_char)(el, lp->lastchar)) == 1) {
    457 		if (lp->lastchar + 1 >= lp->limit &&
    458 		    !ch_enlargebufs(el, (size_t)2))
    459 			break;
    460 		lp->lastchar++;
    461 		if (el->el_flags & UNBUFFERED ||
    462 		    lp->lastchar[-1] == '\r' ||
    463 		    lp->lastchar[-1] == '\n')
    464 			break;
    465 	}
    466 	if (num == -1 && errno == EINTR)
    467 		lp->lastchar = lp->buffer;
    468 	lp->cursor = lp->lastchar;
    469 	*lp->lastchar = '\0';
    470 	*nread = (int)(lp->lastchar - lp->buffer);
    471 	return *nread ? lp->buffer : NULL;
    472 }
    473 
    474 const wchar_t *
    475 el_wgets(EditLine *el, int *nread)
    476 {
    477 	int retval;
    478 	el_action_t cmdnum = 0;
    479 	int num;		/* how many chars we have read at NL */
    480 	wchar_t ch;
    481 	int nrb;
    482 
    483 	if (nread == NULL)
    484 		nread = &nrb;
    485 	*nread = 0;
    486 	el->el_read->read_errno = 0;
    487 
    488 	if (el->el_flags & NO_TTY) {
    489 		el->el_line.lastchar = el->el_line.buffer;
    490 		return noedit_wgets(el, nread);
    491 	}
    492 
    493 #ifdef FIONREAD
    494 	if (el->el_tty.t_mode == EX_IO && el->el_read->macros.level < 0) {
    495 		int chrs = 0;
    496 
    497 		(void) ioctl(el->el_infd, FIONREAD, &chrs);
    498 		if (chrs == 0) {
    499 			if (tty_rawmode(el) < 0) {
    500 				errno = 0;
    501 				*nread = 0;
    502 				return NULL;
    503 			}
    504 		}
    505 	}
    506 #endif /* FIONREAD */
    507 
    508 	if ((el->el_flags & UNBUFFERED) == 0)
    509 		read_prepare(el);
    510 
    511 	if (el->el_flags & EDIT_DISABLED) {
    512 		if ((el->el_flags & UNBUFFERED) == 0)
    513 			el->el_line.lastchar = el->el_line.buffer;
    514 		terminal__flush(el);
    515 		return noedit_wgets(el, nread);
    516 	}
    517 
    518 	for (num = -1; num == -1;) {  /* while still editing this line */
    519 		/* if EOF or error */
    520 		if (read_getcmd(el, &cmdnum, &ch) == -1)
    521 			break;
    522 		if ((size_t)cmdnum >= el->el_map.nfunc) /* BUG CHECK command */
    523 			continue;	/* try again */
    524 		/* now do the real command */
    525 		/* vi redo needs these way down the levels... */
    526 		el->el_state.thiscmd = cmdnum;
    527 		el->el_state.thisch = ch;
    528 		if (el->el_map.type == MAP_VI &&
    529 		    el->el_map.current == el->el_map.key &&
    530 		    el->el_chared.c_redo.pos < el->el_chared.c_redo.lim) {
    531 			if (cmdnum == VI_DELETE_PREV_CHAR &&
    532 			    el->el_chared.c_redo.pos != el->el_chared.c_redo.buf
    533 			    && iswprint(el->el_chared.c_redo.pos[-1]))
    534 				el->el_chared.c_redo.pos--;
    535 			else
    536 				*el->el_chared.c_redo.pos++ = ch;
    537 		}
    538 		retval = (*el->el_map.func[cmdnum]) (el, ch);
    539 
    540 		/* save the last command here */
    541 		el->el_state.lastcmd = cmdnum;
    542 
    543 		/* use any return value */
    544 		switch (retval) {
    545 		case CC_CURSOR:
    546 			re_refresh_cursor(el);
    547 			break;
    548 
    549 		case CC_REDISPLAY:
    550 			re_clear_lines(el);
    551 			re_clear_display(el);
    552 			/* FALLTHROUGH */
    553 
    554 		case CC_REFRESH:
    555 			re_refresh(el);
    556 			break;
    557 
    558 		case CC_REFRESH_BEEP:
    559 			re_refresh(el);
    560 			terminal_beep(el);
    561 			break;
    562 
    563 		case CC_NORM:	/* normal char */
    564 			break;
    565 
    566 		case CC_ARGHACK:	/* Suggested by Rich Salz */
    567 			/* <rsalz (at) pineapple.bbn.com> */
    568 			continue;	/* keep going... */
    569 
    570 		case CC_EOF:	/* end of file typed */
    571 			if ((el->el_flags & UNBUFFERED) == 0)
    572 				num = 0;
    573 			else if (num == -1) {
    574 				*el->el_line.lastchar++ = CONTROL('d');
    575 				el->el_line.cursor = el->el_line.lastchar;
    576 				num = 1;
    577 			}
    578 			break;
    579 
    580 		case CC_NEWLINE:	/* normal end of line */
    581 			num = (int)(el->el_line.lastchar - el->el_line.buffer);
    582 			break;
    583 
    584 		case CC_FATAL:	/* fatal error, reset to known state */
    585 			/* put (real) cursor in a known place */
    586 			re_clear_display(el);	/* reset the display stuff */
    587 			ch_reset(el);	/* reset the input pointers */
    588 			read_clearmacros(&el->el_read->macros);
    589 			re_refresh(el); /* print the prompt again */
    590 			break;
    591 
    592 		case CC_ERROR:
    593 		default:	/* functions we don't know about */
    594 			terminal_beep(el);
    595 			terminal__flush(el);
    596 			break;
    597 		}
    598 		el->el_state.argument = 1;
    599 		el->el_state.doingarg = 0;
    600 		el->el_chared.c_vcmd.action = NOP;
    601 		if (el->el_flags & UNBUFFERED)
    602 			break;
    603 	}
    604 
    605 	terminal__flush(el);		/* flush any buffered output */
    606 	/* make sure the tty is set up correctly */
    607 	if ((el->el_flags & UNBUFFERED) == 0) {
    608 		read_finish(el);
    609 		*nread = num != -1 ? num : 0;
    610 	} else
    611 		*nread = (int)(el->el_line.lastchar - el->el_line.buffer);
    612 
    613 	if (*nread == 0) {
    614 		if (num == -1) {
    615 			*nread = -1;
    616 			if (el->el_read->read_errno)
    617 				errno = el->el_read->read_errno;
    618 		}
    619 		return NULL;
    620 	} else
    621 		return el->el_line.buffer;
    622 }
    623