src/read.c - platform/external/libedit - Git at Google

 /*	$NetBSD: read.c,v 1.106 2019/07/23 10:18:52 christos Exp $	*/

 /*-
  * Copyright (c) 1992, 1993
  *	The Regents of the University of California.  All rights reserved.
  *
  * This code is derived from software contributed to Berkeley by
  * Christos Zoulas of Cornell University.
  *
  * 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 "config.h"
 #if !defined(lint) && !defined(SCCSID)
 #if 0
 static char sccsid[] = "@(#)read.c	8.1 (Berkeley) 6/4/93";
 #else
 __RCSID("$NetBSD: read.c,v 1.106 2019/07/23 10:18:52 christos Exp $");
 #endif
 #endif /* not lint && not SCCSID */

 /*
  * read.c: Terminal read functions
  */
 #include <ctype.h>
 #include <errno.h>
 #include <fcntl.h>
 #include <limits.h>
 #include <stdlib.h>
 #include <string.h>
 #include <unistd.h>

 #include "el.h"
 #include "fcns.h"
 #include "read.h"

 #define	EL_MAXMACRO	10

 struct macros {
 	wchar_t	**macro;
 	int	  level;
 	int	  offset;
 };

 struct el_read_t {
 	struct macros	 macros;
 	el_rfunc_t	 read_char;	/* Function to read a character. */
 	int		 read_errno;
 };

 static int	read__fixio(int, int);
 static int	read_char(EditLine *, wchar_t *);
 static int	read_getcmd(EditLine *, el_action_t *, wchar_t *);
 static void	read_clearmacros(struct macros *);
 static void	read_pop(struct macros *);
 static const wchar_t *noedit_wgets(EditLine *, int *);

 /* read_init():
  *	Initialize the read stuff
  */
 libedit_private int
 read_init(EditLine *el)
 {
 	struct macros *ma;

 	if ((el->el_read = el_malloc(sizeof(*el->el_read))) == NULL)
 		return -1;

 	ma = &el->el_read->macros;
 	if ((ma->macro = el_calloc(EL_MAXMACRO, sizeof(*ma->macro))) == NULL) {
 		free(el->el_read);
 		return -1;
 	}
 	ma->level = -1;
 	ma->offset = 0;

 	/* builtin read_char */
 	el->el_read->read_char = read_char;
 	return 0;
 }

 /* el_read_end():
  *	Free the data structures used by the read stuff.
  */
 libedit_private void
 read_end(struct el_read_t *el_read)
 {
 	read_clearmacros(&el_read->macros);
 	el_free(el_read->macros.macro);
 	el_read->macros.macro = NULL;
 	el_free(el_read);
 }

 /* el_read_setfn():
  *	Set the read char function to the one provided.
  *	If it is set to EL_BUILTIN_GETCFN, then reset to the builtin one.
  */
 libedit_private int
 el_read_setfn(struct el_read_t *el_read, el_rfunc_t rc)
 {
 	el_read->read_char = (rc == EL_BUILTIN_GETCFN) ? read_char : rc;
 	return 0;
 }


 /* el_read_getfn():
  *	return the current read char function, or EL_BUILTIN_GETCFN
  *	if it is the default one
  */
 libedit_private el_rfunc_t
 el_read_getfn(struct el_read_t *el_read)
 {
        return el_read->read_char == read_char ?
 	    EL_BUILTIN_GETCFN : el_read->read_char;
 }


 /* read__fixio():
  *	Try to recover from a read error
  */
 /* ARGSUSED */
 static int
 read__fixio(int fd __attribute__((__unused__)), int e)
 {

 	switch (e) {
 	case -1:		/* Make sure that the code is reachable */

 #ifdef EWOULDBLOCK
 	case EWOULDBLOCK:
 #ifndef TRY_AGAIN
 #define TRY_AGAIN
 #endif
 #endif /* EWOULDBLOCK */

 #if defined(POSIX) && defined(EAGAIN)
 #if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
 	case EAGAIN:
 #ifndef TRY_AGAIN
 #define TRY_AGAIN
 #endif
 #endif /* EWOULDBLOCK && EWOULDBLOCK != EAGAIN */
 #endif /* POSIX && EAGAIN */

 		e = 0;
 #ifdef TRY_AGAIN
 #if defined(F_SETFL) && defined(O_NDELAY)
 		if ((e = fcntl(fd, F_GETFL, 0)) == -1)
 			return -1;

 		if (fcntl(fd, F_SETFL, e & ~O_NDELAY) == -1)
 			return -1;
 		else
 			e = 1;
 #endif /* F_SETFL && O_NDELAY */

 #ifdef FIONBIO
 		{
 			int zero = 0;

 			if (ioctl(fd, FIONBIO, &zero) == -1)
 				return -1;
 			else
 				e = 1;
 		}
 #endif /* FIONBIO */

 #endif /* TRY_AGAIN */
 		return e ? 0 : -1;

 	case EINTR:
 		return 0;

 	default:
 		return -1;
 	}
 }


 /* el_push():
  *	Push a macro
  */
 void
 el_wpush(EditLine *el, const wchar_t *str)
 {
 	struct macros *ma = &el->el_read->macros;

 	if (str != NULL && ma->level + 1 < EL_MAXMACRO) {
 		ma->level++;
 		if ((ma->macro[ma->level] = wcsdup(str)) != NULL)
 			return;
 		ma->level--;
 	}
 	terminal_beep(el);
 	terminal__flush(el);
 }


 /* read_getcmd():
  *	Get next command from the input stream,
  *	return 0 on success or -1 on EOF or error.
  *	Character values > 255 are not looked up in the map, but inserted.
  */
 static int
 read_getcmd(EditLine *el, el_action_t *cmdnum, wchar_t *ch)
 {
 	static const wchar_t meta = (wchar_t)0x80;
 	el_action_t cmd;

 	do {
 		if (el_wgetc(el, ch) != 1)
 			return -1;

 #ifdef	KANJI
 		if ((*ch & meta)) {
 			el->el_state.metanext = 0;
 			cmd = CcViMap[' '];
 			break;
 		} else
 #endif /* KANJI */

 		if (el->el_state.metanext) {
 			el->el_state.metanext = 0;
 			*ch |= meta;
 		}
 		if (*ch >= N_KEYS)
 			cmd = ED_INSERT;
 		else
 			cmd = el->el_map.current[(unsigned char) *ch];
 		if (cmd == ED_SEQUENCE_LEAD_IN) {
 			keymacro_value_t val;
 			switch (keymacro_get(el, ch, &val)) {
 			case XK_CMD:
 				cmd = val.cmd;
 				break;
 			case XK_STR:
 				el_wpush(el, val.str);
 				break;
 			case XK_NOD:
 				return -1;
 			default:
 				EL_ABORT((el->el_errfile, "Bad XK_ type \n"));
 				break;
 			}
 		}
 	} while (cmd == ED_SEQUENCE_LEAD_IN);
 	*cmdnum = cmd;
 	return 0;
 }

 /* read_char():
  *	Read a character from the tty.
  */
 static int
 read_char(EditLine *el, wchar_t *cp)
 {
 	ssize_t num_read;
 	int tried = 0;
 	char cbuf[MB_LEN_MAX];
 	size_t cbp = 0;
 	int save_errno = errno;

  again:
 	el->el_signal->sig_no = 0;
 	while ((num_read = read(el->el_infd, cbuf + cbp, (size_t)1)) == -1) {
 		int e = errno;
 		switch (el->el_signal->sig_no) {
 		case SIGCONT:
 			el_wset(el, EL_REFRESH);
 			/*FALLTHROUGH*/
 		case SIGWINCH:
 			sig_set(el);
 			goto again;
 		default:
 			break;
 		}
 		if (!tried && read__fixio(el->el_infd, e) == 0) {
 			errno = save_errno;
 			tried = 1;
 		} else {
 			errno = e;
 			*cp = L'\0';
 			return -1;
 		}
 	}

 	/* Test for EOF */
 	if (num_read == 0) {
 		*cp = L'\0';
 		return 0;
 	}

 	for (;;) {
 		mbstate_t mbs;

 		++cbp;
 		/* This only works because UTF8 is stateless. */
 		memset(&mbs, 0, sizeof(mbs));
 		switch (mbrtowc(cp, cbuf, cbp, &mbs)) {
 		case (size_t)-1:
 			if (cbp > 1) {
 				/*
 				 * Invalid sequence, discard all bytes
 				 * except the last one.
 				 */
 				cbuf[0] = cbuf[cbp - 1];
 				cbp = 0;
 				break;
 			} else {
 				/* Invalid byte, discard it. */
 				cbp = 0;
 				goto again;
 			}
 		case (size_t)-2:
 			if (cbp >= MB_LEN_MAX) {
 				errno = EILSEQ;
 				*cp = L'\0';
 				return -1;
 			}
 			/* Incomplete sequence, read another byte. */
 			goto again;
 		default:
 			/* Valid character, process it. */
 			return 1;
 		}
 	}
 }

 /* read_pop():
  *	Pop a macro from the stack
  */
 static void
 read_pop(struct macros *ma)
 {
 	int i;

 	el_free(ma->macro[0]);
 	for (i = 0; i < ma->level; i++)
 		ma->macro[i] = ma->macro[i + 1];
 	ma->level--;
 	ma->offset = 0;
 }

 static void
 read_clearmacros(struct macros *ma)
 {
 	while (ma->level >= 0)
 		el_free(ma->macro[ma->level--]);
 	ma->offset = 0;
 }

 /* el_wgetc():
  *	Read a wide character
  */
 int
 el_wgetc(EditLine *el, wchar_t *cp)
 {
 	struct macros *ma = &el->el_read->macros;
 	int num_read;

 	terminal__flush(el);
 	for (;;) {
 		if (ma->level < 0)
 			break;

 		if (ma->macro[0][ma->offset] == '\0') {
 			read_pop(ma);
 			continue;
 		}

 		*cp = ma->macro[0][ma->offset++];

 		if (ma->macro[0][ma->offset] == '\0') {
 			/* Needed for QuoteMode On */
 			read_pop(ma);
 		}

 		return 1;
 	}

 	if (tty_rawmode(el) < 0)/* make sure the tty is set up correctly */
 		return 0;

 	num_read = (*el->el_read->read_char)(el, cp);

 	/*
 	 * Remember the original reason of a read failure
 	 * such that el_wgets() can restore it after doing
 	 * various cleanup operation that might change errno.
 	 */
 	if (num_read < 0)
 		el->el_read->read_errno = errno;

 	return num_read;
 }

 libedit_private void
 read_prepare(EditLine *el)
 {
 	if (el->el_flags & HANDLE_SIGNALS)
 		sig_set(el);
 	if (el->el_flags & NO_TTY)
 		return;
 	if ((el->el_flags & (UNBUFFERED|EDIT_DISABLED)) == UNBUFFERED)
 		tty_rawmode(el);

 	/* This is relatively cheap, and things go terribly wrong if
 	   we have the wrong size. */
 	el_resize(el);
 	re_clear_display(el);	/* reset the display stuff */
 	ch_reset(el);
 	re_refresh(el);		/* print the prompt */

 	if (el->el_flags & UNBUFFERED)
 		terminal__flush(el);
 }

 libedit_private void
 read_finish(EditLine *el)
 {
 	if ((el->el_flags & UNBUFFERED) == 0)
 		(void) tty_cookedmode(el);
 	if (el->el_flags & HANDLE_SIGNALS)
 		sig_clr(el);
 }

 static const wchar_t *
 noedit_wgets(EditLine *el, int *nread)
 {
 	el_line_t	*lp = &el->el_line;
 	int		 num;

 	while ((num = (*el->el_read->read_char)(el, lp->lastchar)) == 1) {
 		if (lp->lastchar + 1 >= lp->limit &&
 		    !ch_enlargebufs(el, (size_t)2))
 			break;
 		lp->lastchar++;
 		if (el->el_flags & UNBUFFERED ||
 		    lp->lastchar[-1] == '\r' ||
 		    lp->lastchar[-1] == '\n')
 			break;
 	}
 	if (num == -1 && errno == EINTR)
 		lp->lastchar = lp->buffer;
 	lp->cursor = lp->lastchar;
 	*lp->lastchar = '\0';
 	*nread = (int)(lp->lastchar - lp->buffer);
 	return *nread ? lp->buffer : NULL;
 }

 const wchar_t *
 el_wgets(EditLine *el, int *nread)
 {
 	int retval;
 	el_action_t cmdnum = 0;
 	int num;		/* how many chars we have read at NL */
 	wchar_t ch;
 	int nrb;

 	if (nread == NULL)
 		nread = &nrb;
 	*nread = 0;
 	el->el_read->read_errno = 0;

 	if (el->el_flags & NO_TTY) {
 		el->el_line.lastchar = el->el_line.buffer;
 		return noedit_wgets(el, nread);
 	}

 #ifdef FIONREAD
 	if (el->el_tty.t_mode == EX_IO && el->el_read->macros.level < 0) {
 		int chrs = 0;

 		(void) ioctl(el->el_infd, FIONREAD, &chrs);
 		if (chrs == 0) {
 			if (tty_rawmode(el) < 0) {
 				errno = 0;
 				*nread = 0;
 				return NULL;
 			}
 		}
 	}
 #endif /* FIONREAD */

 	if ((el->el_flags & UNBUFFERED) == 0)
 		read_prepare(el);

 	if (el->el_flags & EDIT_DISABLED) {
 		if ((el->el_flags & UNBUFFERED) == 0)
 			el->el_line.lastchar = el->el_line.buffer;
 		terminal__flush(el);
 		return noedit_wgets(el, nread);
 	}

 	for (num = -1; num == -1;) {  /* while still editing this line */
 		/* if EOF or error */
 		if (read_getcmd(el, &cmdnum, &ch) == -1)
 			break;
 		if ((size_t)cmdnum >= el->el_map.nfunc) /* BUG CHECK command */
 			continue;	/* try again */
 		/* now do the real command */
 		/* vi redo needs these way down the levels... */
 		el->el_state.thiscmd = cmdnum;
 		el->el_state.thisch = ch;
 		if (el->el_map.type == MAP_VI &&
 		    el->el_map.current == el->el_map.key &&
 		    el->el_chared.c_redo.pos < el->el_chared.c_redo.lim) {
 			if (cmdnum == VI_DELETE_PREV_CHAR &&
 			    el->el_chared.c_redo.pos != el->el_chared.c_redo.buf
 			    && iswprint(el->el_chared.c_redo.pos[-1]))
 				el->el_chared.c_redo.pos--;
 			else
 				*el->el_chared.c_redo.pos++ = ch;
 		}
 		retval = (*el->el_map.func[cmdnum]) (el, ch);

 		/* save the last command here */
 		el->el_state.lastcmd = cmdnum;

 		/* use any return value */
 		switch (retval) {
 		case CC_CURSOR:
 			re_refresh_cursor(el);
 			break;

 		case CC_REDISPLAY:
 			re_clear_lines(el);
 			re_clear_display(el);
 			/* FALLTHROUGH */

 		case CC_REFRESH:
 			re_refresh(el);
 			break;

 		case CC_REFRESH_BEEP:
 			re_refresh(el);
 			terminal_beep(el);
 			break;

 		case CC_NORM:	/* normal char */
 			break;

 		case CC_ARGHACK:	/* Suggested by Rich Salz */
 			/* <rsalz@pineapple.bbn.com> */
 			continue;	/* keep going... */

 		case CC_EOF:	/* end of file typed */
 			if ((el->el_flags & UNBUFFERED) == 0)
 				num = 0;
 			else if (num == -1) {
 				*el->el_line.lastchar++ = CONTROL('d');
 				el->el_line.cursor = el->el_line.lastchar;
 				num = 1;
 			}
 			break;

 		case CC_NEWLINE:	/* normal end of line */
 			num = (int)(el->el_line.lastchar - el->el_line.buffer);
 			break;

 		case CC_FATAL:	/* fatal error, reset to known state */
 			/* put (real) cursor in a known place */
 			re_clear_display(el);	/* reset the display stuff */
 			ch_reset(el);	/* reset the input pointers */
 			read_clearmacros(&el->el_read->macros);
 			re_refresh(el); /* print the prompt again */
 			break;

 		case CC_ERROR:
 		default:	/* functions we don't know about */
 			terminal_beep(el);
 			terminal__flush(el);
 			break;
 		}
 		el->el_state.argument = 1;
 		el->el_state.doingarg = 0;
 		el->el_chared.c_vcmd.action = NOP;
 		if (el->el_flags & UNBUFFERED)
 			break;
 	}

 	terminal__flush(el);		/* flush any buffered output */
 	/* make sure the tty is set up correctly */
 	if ((el->el_flags & UNBUFFERED) == 0) {
 		read_finish(el);
 		*nread = num != -1 ? num : 0;
 	} else
 		*nread = (int)(el->el_line.lastchar - el->el_line.buffer);

 	if (*nread == 0) {
 		if (num == -1) {
 			*nread = -1;
 			if (el->el_read->read_errno)
 				errno = el->el_read->read_errno;
 		}
 		return NULL;
 	} else
 		return el->el_line.buffer;
 }
	/* $NetBSD: read.c,v 1.106 2019/07/23 10:18:52 christos Exp $ */

	/*-
	* Copyright (c) 1992, 1993
	* The Regents of the University of California. All rights reserved.
	*
	* This code is derived from software contributed to Berkeley by
	* Christos Zoulas of Cornell University.
	*
	* 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 "config.h"
	#if !defined(lint) && !defined(SCCSID)
	#if 0
	static char sccsid[] = "@(#)read.c 8.1 (Berkeley) 6/4/93";
	#else
	__RCSID("$NetBSD: read.c,v 1.106 2019/07/23 10:18:52 christos Exp $");
	#endif
	#endif /* not lint && not SCCSID */

	/*
	* read.c: Terminal read functions
	*/
	#include <ctype.h>
	#include <errno.h>
	#include <fcntl.h>
	#include <limits.h>
	#include <stdlib.h>
	#include <string.h>
	#include <unistd.h>

	#include "el.h"
	#include "fcns.h"
	#include "read.h"

	#define EL_MAXMACRO 10

	struct macros {
	wchar_t **macro;
	int level;
	int offset;
	};

	struct el_read_t {
	struct macros macros;
	el_rfunc_t read_char; /* Function to read a character. */
	int read_errno;
	};

	static int read__fixio(int, int);
	static int read_char(EditLine , wchar_t );
	static int read_getcmd(EditLine , el_action_t , wchar_t *);
	static void read_clearmacros(struct macros *);
	static void read_pop(struct macros *);
	static const wchar_t noedit_wgets(EditLine , int *);

	/* read_init():
	* Initialize the read stuff
	*/
	libedit_private int
	read_init(EditLine *el)
	{
	struct macros *ma;

	if ((el->el_read = el_malloc(sizeof(*el->el_read))) == NULL)
	return -1;

	ma = &el->el_read->macros;
	if ((ma->macro = el_calloc(EL_MAXMACRO, sizeof(*ma->macro))) == NULL) {
	free(el->el_read);
	return -1;
	}
	ma->level = -1;
	ma->offset = 0;

	/* builtin read_char */
	el->el_read->read_char = read_char;
	return 0;
	}

	/* el_read_end():
	* Free the data structures used by the read stuff.
	*/
	libedit_private void
	read_end(struct el_read_t *el_read)
	{
	read_clearmacros(&el_read->macros);
	el_free(el_read->macros.macro);
	el_read->macros.macro = NULL;
	el_free(el_read);
	}

	/* el_read_setfn():
	* Set the read char function to the one provided.
	* If it is set to EL_BUILTIN_GETCFN, then reset to the builtin one.
	*/
	libedit_private int
	el_read_setfn(struct el_read_t *el_read, el_rfunc_t rc)
	{
	el_read->read_char = (rc == EL_BUILTIN_GETCFN) ? read_char : rc;
	return 0;
	}


	/* el_read_getfn():
	* return the current read char function, or EL_BUILTIN_GETCFN
	* if it is the default one
	*/
	libedit_private el_rfunc_t
	el_read_getfn(struct el_read_t *el_read)
	{
	return el_read->read_char == read_char ?
	EL_BUILTIN_GETCFN : el_read->read_char;
	}


	/* read__fixio():
	* Try to recover from a read error
	*/
	/* ARGSUSED */
	static int
	read__fixio(int fd __attribute__((__unused__)), int e)
	{

	switch (e) {
	case -1: /* Make sure that the code is reachable */

	#ifdef EWOULDBLOCK
	case EWOULDBLOCK:
	#ifndef TRY_AGAIN
	#define TRY_AGAIN
	#endif
	#endif /* EWOULDBLOCK */

	#if defined(POSIX) && defined(EAGAIN)
	#if defined(EWOULDBLOCK) && EWOULDBLOCK != EAGAIN
	case EAGAIN:
	#ifndef TRY_AGAIN
	#define TRY_AGAIN
	#endif
	#endif /* EWOULDBLOCK && EWOULDBLOCK != EAGAIN */
	#endif /* POSIX && EAGAIN */

	e = 0;
	#ifdef TRY_AGAIN
	#if defined(F_SETFL) && defined(O_NDELAY)
	if ((e = fcntl(fd, F_GETFL, 0)) == -1)
	return -1;

	if (fcntl(fd, F_SETFL, e & ~O_NDELAY) == -1)
	return -1;
	else
	e = 1;
	#endif /* F_SETFL && O_NDELAY */

	#ifdef FIONBIO
	{
	int zero = 0;

	if (ioctl(fd, FIONBIO, &zero) == -1)
	return -1;
	else
	e = 1;
	}
	#endif /* FIONBIO */

	#endif /* TRY_AGAIN */
	return e ? 0 : -1;

	case EINTR:
	return 0;

	default:
	return -1;
	}
	}


	/* el_push():
	* Push a macro
	*/
	void
	el_wpush(EditLine el, const wchar_t str)
	{
	struct macros *ma = &el->el_read->macros;

	if (str != NULL && ma->level + 1 < EL_MAXMACRO) {
	ma->level++;
	if ((ma->macro[ma->level] = wcsdup(str)) != NULL)
	return;
	ma->level--;
	}
	terminal_beep(el);
	terminal__flush(el);
	}


	/* read_getcmd():
	* Get next command from the input stream,
	* return 0 on success or -1 on EOF or error.
	* Character values > 255 are not looked up in the map, but inserted.
	*/
	static int
	read_getcmd(EditLine el, el_action_t cmdnum, wchar_t *ch)
	{
	static const wchar_t meta = (wchar_t)0x80;
	el_action_t cmd;

	do {
	if (el_wgetc(el, ch) != 1)
	return -1;

	#ifdef KANJI
	if ((*ch & meta)) {
	el->el_state.metanext = 0;
	cmd = CcViMap[' '];
	break;
	} else
	#endif /* KANJI */

	if (el->el_state.metanext) {
	el->el_state.metanext = 0;
	*ch \|= meta;
	}
	if (*ch >= N_KEYS)
	cmd = ED_INSERT;
	else
	cmd = el->el_map.current[(unsigned char) *ch];
	if (cmd == ED_SEQUENCE_LEAD_IN) {
	keymacro_value_t val;
	switch (keymacro_get(el, ch, &val)) {
	case XK_CMD:
	cmd = val.cmd;
	break;
	case XK_STR:
	el_wpush(el, val.str);
	break;
	case XK_NOD:
	return -1;
	default:
	EL_ABORT((el->el_errfile, "Bad XK_ type \n"));
	break;
	}
	}
	} while (cmd == ED_SEQUENCE_LEAD_IN);
	*cmdnum = cmd;
	return 0;
	}

	/* read_char():
	* Read a character from the tty.
	*/
	static int
	read_char(EditLine el, wchar_t cp)
	{
	ssize_t num_read;
	int tried = 0;
	char cbuf[MB_LEN_MAX];
	size_t cbp = 0;
	int save_errno = errno;

	again:
	el->el_signal->sig_no = 0;
	while ((num_read = read(el->el_infd, cbuf + cbp, (size_t)1)) == -1) {
	int e = errno;
	switch (el->el_signal->sig_no) {
	case SIGCONT:
	el_wset(el, EL_REFRESH);
	/FALLTHROUGH/
	case SIGWINCH:
	sig_set(el);
	goto again;
	default:
	break;
	}
	if (!tried && read__fixio(el->el_infd, e) == 0) {
	errno = save_errno;
	tried = 1;
	} else {
	errno = e;
	*cp = L'\0';
	return -1;
	}
	}

	/* Test for EOF */
	if (num_read == 0) {
	*cp = L'\0';
	return 0;
	}

	for (;;) {
	mbstate_t mbs;

	++cbp;
	/* This only works because UTF8 is stateless. */
	memset(&mbs, 0, sizeof(mbs));
	switch (mbrtowc(cp, cbuf, cbp, &mbs)) {
	case (size_t)-1:
	if (cbp > 1) {
	/*
	* Invalid sequence, discard all bytes
	* except the last one.
	*/
	cbuf[0] = cbuf[cbp - 1];
	cbp = 0;
	break;
	} else {
	/* Invalid byte, discard it. */
	cbp = 0;
	goto again;
	}
	case (size_t)-2:
	if (cbp >= MB_LEN_MAX) {
	errno = EILSEQ;
	*cp = L'\0';
	return -1;
	}
	/* Incomplete sequence, read another byte. */
	goto again;
	default:
	/* Valid character, process it. */
	return 1;
	}
	}
	}

	/* read_pop():
	* Pop a macro from the stack
	*/
	static void
	read_pop(struct macros *ma)
	{
	int i;

	el_free(ma->macro[0]);
	for (i = 0; i < ma->level; i++)
	ma->macro[i] = ma->macro[i + 1];
	ma->level--;
	ma->offset = 0;
	}

	static void
	read_clearmacros(struct macros *ma)
	{
	while (ma->level >= 0)
	el_free(ma->macro[ma->level--]);
	ma->offset = 0;
	}

	/* el_wgetc():
	* Read a wide character
	*/
	int
	el_wgetc(EditLine el, wchar_t cp)
	{
	struct macros *ma = &el->el_read->macros;
	int num_read;

	terminal__flush(el);
	for (;;) {
	if (ma->level < 0)
	break;

	if (ma->macro[0][ma->offset] == '\0') {
	read_pop(ma);
	continue;
	}

	*cp = ma->macro[0][ma->offset++];

	if (ma->macro[0][ma->offset] == '\0') {
	/* Needed for QuoteMode On */
	read_pop(ma);
	}

	return 1;
	}

	if (tty_rawmode(el) < 0)/* make sure the tty is set up correctly */
	return 0;

	num_read = (*el->el_read->read_char)(el, cp);

	/*
	* Remember the original reason of a read failure
	* such that el_wgets() can restore it after doing
	* various cleanup operation that might change errno.
	*/
	if (num_read < 0)
	el->el_read->read_errno = errno;

	return num_read;
	}

	libedit_private void
	read_prepare(EditLine *el)
	{
	if (el->el_flags & HANDLE_SIGNALS)
	sig_set(el);
	if (el->el_flags & NO_TTY)
	return;
	if ((el->el_flags & (UNBUFFERED\|EDIT_DISABLED)) == UNBUFFERED)
	tty_rawmode(el);

	/* This is relatively cheap, and things go terribly wrong if
	we have the wrong size. */
	el_resize(el);
	re_clear_display(el); /* reset the display stuff */
	ch_reset(el);
	re_refresh(el); /* print the prompt */

	if (el->el_flags & UNBUFFERED)
	terminal__flush(el);
	}

	libedit_private void
	read_finish(EditLine *el)
	{
	if ((el->el_flags & UNBUFFERED) == 0)
	(void) tty_cookedmode(el);
	if (el->el_flags & HANDLE_SIGNALS)
	sig_clr(el);
	}

	static const wchar_t *
	noedit_wgets(EditLine el, int nread)
	{
	el_line_t *lp = &el->el_line;
	int num;

	while ((num = (*el->el_read->read_char)(el, lp->lastchar)) == 1) {
	if (lp->lastchar + 1 >= lp->limit &&
	!ch_enlargebufs(el, (size_t)2))
	break;
	lp->lastchar++;
	if (el->el_flags & UNBUFFERED \|\|
	lp->lastchar[-1] == '\r' \|\|
	lp->lastchar[-1] == '\n')
	break;
	}
	if (num == -1 && errno == EINTR)
	lp->lastchar = lp->buffer;
	lp->cursor = lp->lastchar;
	*lp->lastchar = '\0';
	*nread = (int)(lp->lastchar - lp->buffer);
	return *nread ? lp->buffer : NULL;
	}

	const wchar_t *
	el_wgets(EditLine el, int nread)
	{
	int retval;
	el_action_t cmdnum = 0;
	int num; /* how many chars we have read at NL */
	wchar_t ch;
	int nrb;

	if (nread == NULL)
	nread = &nrb;
	*nread = 0;
	el->el_read->read_errno = 0;

	if (el->el_flags & NO_TTY) {
	el->el_line.lastchar = el->el_line.buffer;
	return noedit_wgets(el, nread);
	}

	#ifdef FIONREAD
	if (el->el_tty.t_mode == EX_IO && el->el_read->macros.level < 0) {
	int chrs = 0;

	(void) ioctl(el->el_infd, FIONREAD, &chrs);
	if (chrs == 0) {
	if (tty_rawmode(el) < 0) {
	errno = 0;
	*nread = 0;
	return NULL;
	}
	}
	}
	#endif /* FIONREAD */

	if ((el->el_flags & UNBUFFERED) == 0)
	read_prepare(el);

	if (el->el_flags & EDIT_DISABLED) {
	if ((el->el_flags & UNBUFFERED) == 0)
	el->el_line.lastchar = el->el_line.buffer;
	terminal__flush(el);
	return noedit_wgets(el, nread);
	}

	for (num = -1; num == -1;) { /* while still editing this line */
	/* if EOF or error */
	if (read_getcmd(el, &cmdnum, &ch) == -1)
	break;
	if ((size_t)cmdnum >= el->el_map.nfunc) /* BUG CHECK command */
	continue; /* try again */
	/* now do the real command */
	/* vi redo needs these way down the levels... */
	el->el_state.thiscmd = cmdnum;
	el->el_state.thisch = ch;
	if (el->el_map.type == MAP_VI &&
	el->el_map.current == el->el_map.key &&
	el->el_chared.c_redo.pos < el->el_chared.c_redo.lim) {
	if (cmdnum == VI_DELETE_PREV_CHAR &&
	el->el_chared.c_redo.pos != el->el_chared.c_redo.buf
	&& iswprint(el->el_chared.c_redo.pos[-1]))
	el->el_chared.c_redo.pos--;
	else
	*el->el_chared.c_redo.pos++ = ch;
	}
	retval = (*el->el_map.func[cmdnum]) (el, ch);

	/* save the last command here */
	el->el_state.lastcmd = cmdnum;

	/* use any return value */
	switch (retval) {
	case CC_CURSOR:
	re_refresh_cursor(el);
	break;

	case CC_REDISPLAY:
	re_clear_lines(el);
	re_clear_display(el);
	/* FALLTHROUGH */

	case CC_REFRESH:
	re_refresh(el);
	break;

	case CC_REFRESH_BEEP:
	re_refresh(el);
	terminal_beep(el);
	break;

	case CC_NORM: /* normal char */
	break;

	case CC_ARGHACK: /* Suggested by Rich Salz */
	/* <rsalz@pineapple.bbn.com> */
	continue; /* keep going... */

	case CC_EOF: /* end of file typed */
	if ((el->el_flags & UNBUFFERED) == 0)
	num = 0;
	else if (num == -1) {
	*el->el_line.lastchar++ = CONTROL('d');
	el->el_line.cursor = el->el_line.lastchar;
	num = 1;
	}
	break;

	case CC_NEWLINE: /* normal end of line */
	num = (int)(el->el_line.lastchar - el->el_line.buffer);
	break;

	case CC_FATAL: /* fatal error, reset to known state */
	/* put (real) cursor in a known place */
	re_clear_display(el); /* reset the display stuff */
	ch_reset(el); /* reset the input pointers */
	read_clearmacros(&el->el_read->macros);
	re_refresh(el); /* print the prompt again */
	break;

	case CC_ERROR:
	default: /* functions we don't know about */
	terminal_beep(el);
	terminal__flush(el);
	break;
	}
	el->el_state.argument = 1;
	el->el_state.doingarg = 0;
	el->el_chared.c_vcmd.action = NOP;
	if (el->el_flags & UNBUFFERED)
	break;
	}

	terminal__flush(el); /* flush any buffered output */
	/* make sure the tty is set up correctly */
	if ((el->el_flags & UNBUFFERED) == 0) {
	read_finish(el);
	*nread = num != -1 ? num : 0;
	} else
	*nread = (int)(el->el_line.lastchar - el->el_line.buffer);

	if (*nread == 0) {
	if (num == -1) {
	*nread = -1;
	if (el->el_read->read_errno)
	errno = el->el_read->read_errno;
	}
	return NULL;
	} else
	return el->el_line.buffer;
	}