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output.c revision 1.5
      1 /*	$NetBSD: output.c,v 1.5 1999/10/19 23:09:45 dan Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1988 Mark Nudleman
      5  * Copyright (c) 1988, 1993
      6  *	The Regents of the University of California.  All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *	This product includes software developed by the University of
     19  *	California, Berkeley and its contributors.
     20  * 4. Neither the name of the University nor the names of its contributors
     21  *    may be used to endorse or promote products derived from this software
     22  *    without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  * SUCH DAMAGE.
     35  */
     36 
     37 #include <sys/cdefs.h>
     38 #ifndef lint
     39 #if 0
     40 static char sccsid[] = "@(#)output.c	8.2 (Berkeley) 4/27/95";
     41 #else
     42 __RCSID("$NetBSD: output.c,v 1.5 1999/10/19 23:09:45 dan Exp $");
     43 #endif
     44 #endif /* not lint */
     45 
     46 /*
     47  * High level routines dealing with the output to the screen.
     48  */
     49 
     50 #include <stdio.h>
     51 #include <string.h>
     52 #include <unistd.h>
     53 #include <stdlib.h>
     54 
     55 #include "less.h"
     56 #include "extern.h"
     57 
     58 int errmsgs;	/* Count of messages displayed by error() */
     59 
     60 /* display the line which is in the line buffer. */
     61 void
     62 put_line()
     63 {
     64 	char *p;
     65 	int c;
     66 	int column;
     67 
     68 	if (sigs)
     69 	{
     70 		/*
     71 		 * Don't output if a signal is pending.
     72 		 */
     73 		screen_trashed = 1;
     74 		return;
     75 	}
     76 
     77 	if (line == NULL)
     78 		line = "";
     79 
     80 	column = 0;
     81 	for (p = line;  *p != '\0';  p++)
     82 	{
     83 		switch (c = *p)
     84 		{
     85 		case UL_CHAR:
     86 			ul_enter();
     87 			column += ul_width +1;
     88 			break;
     89 		case UE_CHAR:
     90 			ul_exit();
     91 			column += ue_width;
     92 			break;
     93 		case BO_CHAR:
     94 			bo_enter();
     95 			column += bo_width +1;
     96 			break;
     97 		case BE_CHAR:
     98 			bo_exit();
     99 			column += be_width;
    100 			break;
    101 		case '\t':
    102 			do
    103 			{
    104 				putchr(' ');
    105 				column++;
    106 			} while ((column % tabstop) != 0);
    107 			break;
    108 		case '\b':
    109 			putbs();
    110 			column--;
    111 			break;
    112 		default:
    113 			if (c & 0200)
    114 			{
    115 				/*
    116 				 * Control characters arrive here as the
    117 				 * normal character [CARAT_CHAR(c)] with
    118 				 * the 0200 bit set.  See pappend().
    119 				 */
    120 				putchr('^');
    121 				putchr(c & 0177);
    122 				column += 2;
    123 			} else
    124 			{
    125 				putchr(c);
    126 				column++;
    127 			}
    128 		}
    129 	}
    130 	if (column < sc_width || !auto_wrap || ignaw)
    131 		putchr('\n');
    132 }
    133 
    134 static char obuf[1024];
    135 static char *ob = obuf;
    136 
    137 /*
    138  * Flush buffered output.
    139  */
    140 void
    141 flush()
    142 {
    143 	int n;
    144 
    145 	n = ob - obuf;
    146 	if (n == 0)
    147 		return;
    148 	if (write(1, obuf, n) != n)
    149 		screen_trashed = 1;
    150 	ob = obuf;
    151 }
    152 
    153 /*
    154  * Purge any pending output.
    155  */
    156 void
    157 purge()
    158 {
    159 
    160 	ob = obuf;
    161 }
    162 
    163 /*
    164  * Output a character.
    165  */
    166 int
    167 putchr(c)
    168 	int c;
    169 {
    170 	if (ob >= &obuf[sizeof(obuf)])
    171 		flush();
    172 	*ob++ = c;
    173 }
    174 
    175 /*
    176  * Output a string.
    177  */
    178 void
    179 putstr(s)
    180 	char *s;
    181 {
    182 	while (*s != '\0')
    183 		putchr(*s++);
    184 }
    185 
    186 int cmdstack;
    187 static char return_to_continue[] = "(press RETURN)";
    188 
    189 /*
    190  * Output a message in the lower left corner of the screen
    191  * and wait for carriage return.
    192  */
    193 void
    194 error(s)
    195 	char *s;
    196 {
    197 	int ch;
    198 
    199 	++errmsgs;
    200 	if (!any_display) {
    201 		/*
    202 		 * Nothing has been displayed yet.  Output this message on
    203 		 * error output (file descriptor 2) and don't wait for a
    204 		 * keystroke to continue.
    205 		 *
    206 		 * This has the desirable effect of producing all error
    207 		 * messages on error output if standard output is directed
    208 		 * to a file.  It also does the same if we never produce
    209 		 * any real output; for example, if the input file(s) cannot
    210 		 * be opened.  If we do eventually produce output, code in
    211 		 * edit() makes sure these messages can be seen before they
    212 		 * are overwritten or scrolled away.
    213 		 */
    214 		if (s != NULL) {
    215 			(void)write(2, s, strlen(s));
    216 			(void)write(2, "\n", 1);
    217 		}
    218 		return;
    219 	}
    220 
    221 	lower_left();
    222 	clear_eol();
    223 	so_enter();
    224 	if (s != NULL) {
    225 		putstr(s);
    226 		putstr("  ");
    227 	}
    228 	putstr(return_to_continue);
    229 	so_exit();
    230 
    231 	if ((ch = getchr()) != '\n') {
    232 		if (ch == 'q')
    233 			quit();
    234 		cmdstack = ch;
    235 	}
    236 	lower_left();
    237 
    238 	if ((s != NULL ? strlen(s) : 0) + sizeof(return_to_continue) +
    239 		so_width + se_width + 1 > sc_width)
    240 		/*
    241 		 * Printing the message has probably scrolled the screen.
    242 		 * {{ Unless the terminal doesn't have auto margins,
    243 		 *    in which case we just hammered on the right margin. }}
    244 		 */
    245 		repaint();
    246 	flush();
    247 }
    248 
    249 static char intr_to_abort[] = "... (interrupt to abort)";
    250 
    251 void
    252 ierror(s)
    253 	char *s;
    254 {
    255 	lower_left();
    256 	clear_eol();
    257 	so_enter();
    258 	putstr(s);
    259 	putstr(intr_to_abort);
    260 	so_exit();
    261 	flush();
    262 }
    263