text: /*	$OpenBSD: read.c,v 1.13 2010/06/30 00:05:35 nicm Exp $	*/
  /*	$NetBSD: read.c,v 1.55 2010/03/22 22:59:06 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"
  
  /*
   * read.c: Clean this junk up! This is horrible code.
   *	   Terminal read functions
   */
  #include <errno.h>
  #include <fcntl.h>
  #include <unistd.h>
  #include <stdlib.h>
  #include <limits.h>
  #include "el.h"
  
  #define	OKCMD	-1	/* must be -1! */
  
  private int	read__fixio(int, int);
  private int	read_preread(EditLine *);
  private int	read_char(EditLine *, Char *);
  private int	read_getcmd(EditLine *, el_action_t *, Char *);
  private void	read_pop(c_macro_t *);
  
  /* read_init():
   *	Initialize the read stuff
   */
  protected int
  read_init(EditLine *el)
  {
  	/* builtin read_char */
  	el->el_read.read_char = read_char;
  	return 0;
  }
  
  
  /* 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.
   */
  protected int
  el_read_setfn(EditLine *el, el_rfunc_t rc)
  {
  	el->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
   */
  protected el_rfunc_t
  el_read_getfn(EditLine *el)
  {
         return (el->el_read.read_char == read_char) ?
  	    EL_BUILTIN_GETCFN : el->el_read.read_char;
  }
  
  
  #ifndef MIN
  #define MIN(A,B) ((A) < (B) ? (A) : (B))
  #endif
  
  #ifdef DEBUG_EDIT
  private void
  read_debug(EditLine *el)
  {
  
  	if (el->el_line.cursor > el->el_line.lastchar)
  		(void) fprintf(el->el_errfile, "cursor > lastchar\r\n");
  	if (el->el_line.cursor < el->el_line.buffer)
  		(void) fprintf(el->el_errfile, "cursor < buffer\r\n");
  	if (el->el_line.cursor > el->el_line.limit)
  		(void) fprintf(el->el_errfile, "cursor > limit\r\n");
  	if (el->el_line.lastchar > el->el_line.limit)
  		(void) fprintf(el->el_errfile, "lastchar > limit\r\n");
  	if (el->el_line.limit != &el->el_line.buffer[EL_BUFSIZ - 2])
  		(void) fprintf(el->el_errfile, "limit != &buffer[EL_BUFSIZ-2]\r\n");
  }
  #endif /* DEBUG_EDIT */
  
  
  /* read__fixio():
   *	Try to recover from a read error
   */
  /* ARGSUSED */
  private 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, (ioctl_t) & zero) == -1)
  				return (-1);
  			else
  				e = 1;
  		}
  #endif /* FIONBIO */
  
  #endif /* TRY_AGAIN */
  		return (e ? 0 : -1);
  
  	case EINTR:
  		return (0);
  
  	default:
  		return (-1);
  	}
  }
  
  
  /* read_preread():
   *	Try to read the stuff in the input queue;
   */
  private int
  read_preread(EditLine *el)
  {
  	int chrs = 0;
  
  	if (el->el_tty.t_mode == ED_IO)
  		return (0);
  
  #ifndef WIDECHAR
  /* FIONREAD attempts to buffer up multiple bytes, and to make that work
   * properly with partial wide/UTF-8 characters would need some careful work. */
  #ifdef FIONREAD
  	(void) ioctl(el->el_infd, FIONREAD, (ioctl_t) & chrs);
  	if (chrs > 0) {
  		char buf[EL_BUFSIZ];
  
  		chrs = read(el->el_infd, buf,
  		    (size_t) MIN(chrs, EL_BUFSIZ - 1));
  		if (chrs > 0) {
  			buf[chrs] = '\0';
  			el_push(el, buf);
  		}
  	}
  #endif /* FIONREAD */
  #endif
  	return (chrs > 0);
  }
  
  
  /* el_push():
   *	Push a macro
   */
  public void
  FUN(el,push)(EditLine *el, const Char *str)
  {
  	c_macro_t *ma = &el->el_chared.c_macro;
  
  	if (str != NULL && ma->level + 1 < EL_MAXMACRO) {
  		ma->level++;
  		if ((ma->macro[ma->level] = Strdup(str)) != NULL)
  			return;
  		ma->level--;
  	}
  	term_beep(el);
  	term__flush(el);
  }
  
  
  /* read_getcmd():
   *	Return next command from the input stream.
   *	Character values > 255 are not looked up in the map, but inserted.
   */
  private int
  read_getcmd(EditLine *el, el_action_t *cmdnum, Char *ch)
  {
  	el_action_t cmd;
  	int num;
  
  	el->el_errno = 0;
  	do {
  		if ((num = FUN(el,getc)(el, ch)) != 1) {/* if EOF or error */
  			el->el_errno = num == 0 ? 0 : errno;
  			return (num);
  		}
  
  #ifdef	KANJI
  		if ((*ch & 0200)) {
  			el->el_state.metanext = 0;
  			cmd = CcViMap[' '];
  			break;
  		} else
  #endif /* KANJI */
  
  		if (el->el_state.metanext) {
  			el->el_state.metanext = 0;
  			*ch |= 0200;
  		}
  #ifdef WIDECHAR
                  if (*ch >= N_KEYS)
                          cmd = ED_INSERT;
  		else
  #endif
                          cmd = el->el_map.current[(unsigned char) *ch];
  		if (cmd == ED_SEQUENCE_LEAD_IN) {
  			key_value_t val;
  			switch (key_get(el, ch, &val)) {
  			case XK_CMD:
  				cmd = val.cmd;
  				break;
  			case XK_STR:
  				FUN(el,push)(el, val.str);
  				break;
  #ifdef notyet
  			case XK_EXE:
  				/* XXX: In the future to run a user function */
  				RunCommand(val.str);
  				break;
  #endif
  			default:
  				EL_ABORT((el->el_errfile, "Bad XK_ type \n"));
  				break;
  			}
  		}
  		if (el->el_map.alt == NULL)
  			el->el_map.current = el->el_map.key;
  	} while (cmd == ED_SEQUENCE_LEAD_IN);
  	*cmdnum = cmd;
  	return (OKCMD);
  }
  
  #ifdef WIDECHAR
  /* utf8_islead():
   *      Test whether a byte is a leading byte of a UTF-8 sequence.
   */
  private int
  utf8_islead(unsigned char c)
  {
          return (c < 0x80) ||             /* single byte char */
                 (c >= 0xc2 && c <= 0xf4); /* start of multibyte sequence */
  }
  #endif
  
  /* read_char():
   *	Read a character from the tty.
   */
  private int
  read_char(EditLine *el, Char *cp)
  {
  	ssize_t num_read;
  	int tried = 0;
          char cbuf[MB_LEN_MAX];
          int cbp = 0;
          int bytes = 0;
  
   again:
  	el->el_signal->sig_no = 0;
  	while ((num_read = read(el->el_infd, cbuf + cbp, 1)) == -1) {
  		if (el->el_signal->sig_no == SIGCONT) {
  			sig_set(el);
  			el_set(el, EL_REFRESH);
  			goto again;
  		}
  		if (!tried && read__fixio(el->el_infd, errno) == 0)
  			tried = 1;
  		else {
  			*cp = '\0';
  			return (-1);
  		}
  	}
  
  #ifdef WIDECHAR
  	if (el->el_flags & CHARSET_IS_UTF8) {
  		if (!utf8_islead((unsigned char)cbuf[0]))
  			goto again; /* discard the byte we read and try again */
  		++cbp;
  		if ((bytes = ct_mbtowc(cp, cbuf, cbp)) == -1) {
  			ct_mbtowc_reset;
  			if (cbp >= MB_LEN_MAX) { /* "shouldn't happen" */
  				*cp = '\0';
  				return (-1);
  			}
  			goto again;
  		}
  	} else  /* we don't support other multibyte charsets */
  #endif
  		*cp = (unsigned char)cbuf[0];
  
  	if ((el->el_flags & IGNORE_EXTCHARS) && bytes > 1) {
  		cbp = 0; /* skip this character */
  		goto again;
  	}
  
  	return (int)num_read;
  }
  
  /* read_pop():
   *	Pop a macro from the stack
   */
  private void
  read_pop(c_macro_t *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;
  }
  
  /* el_getc():
   *	Read a character
   */
  public int
  FUN(el,getc)(EditLine *el, Char *cp)
  {
  	int num_read;
  	c_macro_t *ma = &el->el_chared.c_macro;
  
  	term__flush(el);
  	for (;;) {
  		if (ma->level < 0) {
  			if (!read_preread(el))
  				break;
  		}
  
  		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);
  	}
  
  #ifdef DEBUG_READ
  	(void) fprintf(el->el_errfile, "Turning raw mode on\n");
  #endif /* DEBUG_READ */
  	if (tty_rawmode(el) < 0)/* make sure the tty is set up correctly */
  		return (0);
  
  #ifdef DEBUG_READ
  	(void) fprintf(el->el_errfile, "Reading a character\n");
  #endif /* DEBUG_READ */
  	num_read = (*el->el_read.read_char)(el, cp);
  #ifdef WIDECHAR
  	if (el->el_flags & NARROW_READ)
  		*cp = *(char *)(void *)cp;
  #endif
  #ifdef DEBUG_READ
  	(void) fprintf(el->el_errfile, "Got it %c\n", *cp);
  #endif /* DEBUG_READ */
  	return (num_read);
  }
  
  protected 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, 0);
  	re_refresh(el);		/* print the prompt */
  
  	if (el->el_flags & UNBUFFERED)
  		term__flush(el);
  }
  
  protected void
  read_finish(EditLine *el)
  {
  	if ((el->el_flags & UNBUFFERED) == 0)
  		(void) tty_cookedmode(el);
  	if (el->el_flags & HANDLE_SIGNALS)
  		sig_clr(el);
  }
  
  public const Char *
  FUN(el,gets)(EditLine *el, int *nread)
  {
  	int retval;
  	el_action_t cmdnum = 0;
  	int num;		/* how many chars we have read at NL */
  	Char ch;
  	int crlf = 0;
  	int nrb;
  #ifdef FIONREAD
  	c_macro_t *ma = &el->el_chared.c_macro;
  #endif /* FIONREAD */
  
  	if (nread == NULL)
  		nread = &nrb;
  	*nread = 0;
  
  	if (el->el_flags & NO_TTY) {
  		Char *cp = el->el_line.buffer;
  		size_t idx;
  
  		while ((num = (*el->el_read.read_char)(el, cp)) == 1) {
  			/* make sure there is space for next character */
  			if (cp + 1 >= el->el_line.limit) {
  				idx = (cp - el->el_line.buffer);
  				if (!ch_enlargebufs(el, 2))
  					break;
  				cp = &el->el_line.buffer[idx];
  			}
  			cp++;
  			if (el->el_flags & UNBUFFERED)
  				break;
  			if (cp[-1] == '\r' || cp[-1] == '\n')
  				break;
  		}
  		if (num == -1) {
  			if (errno == EINTR)
  				cp = el->el_line.buffer;
  			el->el_errno = errno;
  		}
  
  		el->el_line.cursor = el->el_line.lastchar = cp;
  		*cp = '\0';
  		*nread = (int)(el->el_line.cursor - el->el_line.buffer);
  		goto done;
  	}
  
  
  #ifdef FIONREAD
  	if (el->el_tty.t_mode == EX_IO && ma->level < 0) {
  		long chrs = 0;
  
  		(void) ioctl(el->el_infd, FIONREAD, (ioctl_t) & 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) {
  		Char *cp;
  		size_t idx;
  
  		if ((el->el_flags & UNBUFFERED) == 0)
  			cp = el->el_line.buffer;
  		else
  			cp = el->el_line.lastchar;
  
  		term__flush(el);
  
  		while ((num = (*el->el_read.read_char)(el, cp)) == 1) {
  			/* make sure there is space next character */
  			if (cp + 1 >= el->el_line.limit) {
  				idx = (cp - el->el_line.buffer);
  				if (!ch_enlargebufs(el, 2))
  					break;
  				cp = &el->el_line.buffer[idx];
  			}
  			cp++;
  			crlf = cp[-1] == '\r' || cp[-1] == '\n';
  			if (el->el_flags & UNBUFFERED)
  				break;
  			if (crlf)
  				break;
  		}
  
  		if (num == -1) {
  			if (errno == EINTR)
  				cp = el->el_line.buffer;
  			el->el_errno = errno;
  		}
  
  		el->el_line.cursor = el->el_line.lastchar = cp;
  		*cp = '\0';
  		goto done;
  	}
  
  	for (num = OKCMD; num == OKCMD;) {	/* while still editing this
  						 * line */
  #ifdef DEBUG_EDIT
  		read_debug(el);
  #endif /* DEBUG_EDIT */
  		/* if EOF or error */
  		if ((num = read_getcmd(el, &cmdnum, &ch)) != OKCMD) {
  #ifdef DEBUG_READ
  			(void) fprintf(el->el_errfile,
  			    "Returning from el_gets %d\n", num);
  #endif /* DEBUG_READ */
  			break;
  		}
  		if (el->el_errno == EINTR) {
  			el->el_line.buffer[0] = '\0';
  			el->el_line.lastchar =
  			    el->el_line.cursor = el->el_line.buffer;
  			break;
  		}
  		if ((unsigned int)cmdnum >= (unsigned int)el->el_map.nfunc) {	/* BUG CHECK command */
  #ifdef DEBUG_EDIT
  			(void) fprintf(el->el_errfile,
  			    "ERROR: illegal command from key 0%o\r\n", ch);
  #endif /* DEBUG_EDIT */
  			continue;	/* try again */
  		}
  		/* now do the real command */
  #ifdef DEBUG_READ
  		{
  			el_bindings_t *b;
  			for (b = el->el_map.help; b->name; b++)
  				if (b->func == cmdnum)
  					break;
  			if (b->name)
  				(void) fprintf(el->el_errfile,
  				    "Executing %s\n", b->name);
  			else
  				(void) fprintf(el->el_errfile,
  				    "Error command = %d\n", cmdnum);
  		}
  #endif /* DEBUG_READ */
  		/* 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
  			    && Isprint(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);
  #ifdef DEBUG_READ
  		(void) fprintf(el->el_errfile,
  			"Returned state %d\n", retval );
  #endif /* DEBUG_READ */
  
  		/* 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);
  			term_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 */
  #ifdef DEBUG_READ
  			(void) fprintf(el->el_errfile,
  			    "*** editor fatal ERROR ***\r\n\n");
  #endif /* DEBUG_READ */
  			/* put (real) cursor in a known place */
  			re_clear_display(el);	/* reset the display stuff */
  			ch_reset(el, 1);	/* reset the input pointers */
  			re_refresh(el);	/* print the prompt again */
  			break;
  
  		case CC_ERROR:
  		default:	/* functions we don't know about */
  #ifdef DEBUG_READ
  			(void) fprintf(el->el_errfile,
  			    "*** editor ERROR ***\r\n\n");
  #endif /* DEBUG_READ */
  			term_beep(el);
  			term__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;
  	}
  
  	term__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);
  	}
  done:
  	if (*nread == 0) {
  		if (num == -1) {
  			*nread = -1;
  			errno = el->el_errno;
  		}
  		return NULL;
  	} else
  		return el->el_line.buffer;
  }
  