xref: /netbsd/distrib/utils/more/output.c (revision 52275243)
1 /*	$NetBSD: output.c,v 1.8 2009/01/24 13:58:21 tsutsui Exp $	*/
2 
3 /*
4  * Copyright (c) 1988 Mark Nudelman
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. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  */
32 
33 #include <sys/cdefs.h>
34 #ifndef lint
35 #if 0
36 static char sccsid[] = "@(#)output.c	8.2 (Berkeley) 4/27/95";
37 #else
38 __RCSID("$NetBSD: output.c,v 1.8 2009/01/24 13:58:21 tsutsui Exp $");
39 #endif
40 #endif /* not lint */
41 
42 /*
43  * High level routines dealing with the output to the screen.
44  */
45 
46 #include <stdio.h>
47 #include <string.h>
48 #include <unistd.h>
49 #include <stdlib.h>
50 
51 #include "less.h"
52 #include "extern.h"
53 
54 int errmsgs;	/* Count of messages displayed by error() */
55 
56 /* display the line which is in the line buffer. */
57 void
put_line()58 put_line()
59 {
60 	char *p;
61 	int c;
62 	int column;
63 
64 	if (sigs)
65 	{
66 		/*
67 		 * Don't output if a signal is pending.
68 		 */
69 		screen_trashed = 1;
70 		return;
71 	}
72 
73 	if (line == NULL)
74 		line = "";
75 
76 	column = 0;
77 	for (p = line;  *p != '\0';  p++)
78 	{
79 		switch (c = *p)
80 		{
81 		case UL_CHAR:
82 			ul_enter();
83 			column += ul_width +1;
84 			break;
85 		case UE_CHAR:
86 			ul_exit();
87 			column += ue_width;
88 			break;
89 		case BO_CHAR:
90 			bo_enter();
91 			column += bo_width +1;
92 			break;
93 		case BE_CHAR:
94 			bo_exit();
95 			column += be_width;
96 			break;
97 		case '\t':
98 			do
99 			{
100 				putchr(' ');
101 				column++;
102 			} while ((column % tabstop) != 0);
103 			break;
104 		case '\b':
105 			putbs();
106 			column--;
107 			break;
108 		default:
109 			if (c & 0200)
110 			{
111 				/*
112 				 * Control characters arrive here as the
113 				 * normal character [CARAT_CHAR(c)] with
114 				 * the 0200 bit set.  See pappend().
115 				 */
116 				putchr('^');
117 				putchr(c & 0177);
118 				column += 2;
119 			} else
120 			{
121 				putchr(c);
122 				column++;
123 			}
124 		}
125 	}
126 	if (column < sc_width || !auto_wrap || ignaw)
127 		putchr('\n');
128 }
129 
130 static char obuf[1024];
131 static char *ob = obuf;
132 
133 /*
134  * Flush buffered output.
135  */
136 void
flush()137 flush()
138 {
139 	int n;
140 
141 	n = ob - obuf;
142 	if (n == 0)
143 		return;
144 	if (write(1, obuf, n) != n)
145 		screen_trashed = 1;
146 	ob = obuf;
147 }
148 
149 /*
150  * Purge any pending output.
151  */
152 void
purge()153 purge()
154 {
155 
156 	ob = obuf;
157 }
158 
159 /*
160  * Output a character.
161  */
162 int
putchr(c)163 putchr(c)
164 	int c;
165 {
166 	if (ob >= &obuf[sizeof(obuf)])
167 		flush();
168 	*ob++ = c;
169 	return c;
170 }
171 
172 /*
173  * Output a string.
174  */
175 void
putstr(s)176 putstr(s)
177 	char *s;
178 {
179 	while (*s != '\0')
180 		putchr(*s++);
181 }
182 
183 int cmdstack;
184 static char return_to_continue[] = "(press RETURN)";
185 
186 /*
187  * Output a message in the lower left corner of the screen
188  * and wait for carriage return.
189  */
190 void
error(s)191 error(s)
192 	char *s;
193 {
194 	int ch;
195 
196 	++errmsgs;
197 	if (!any_display) {
198 		/*
199 		 * Nothing has been displayed yet.  Output this message on
200 		 * error output (file descriptor 2) and don't wait for a
201 		 * keystroke to continue.
202 		 *
203 		 * This has the desirable effect of producing all error
204 		 * messages on error output if standard output is directed
205 		 * to a file.  It also does the same if we never produce
206 		 * any real output; for example, if the input file(s) cannot
207 		 * be opened.  If we do eventually produce output, code in
208 		 * edit() makes sure these messages can be seen before they
209 		 * are overwritten or scrolled away.
210 		 */
211 		if (s != NULL) {
212 			(void)write(2, s, strlen(s));
213 			(void)write(2, "\n", 1);
214 		}
215 		return;
216 	}
217 
218 	lower_left();
219 	clear_eol();
220 	so_enter();
221 	if (s != NULL) {
222 		putstr(s);
223 		putstr("  ");
224 	}
225 	putstr(return_to_continue);
226 	so_exit();
227 
228 	if ((ch = getchr()) != '\n') {
229 		if (ch == 'q')
230 			quit();
231 		cmdstack = ch;
232 	}
233 	lower_left();
234 
235 	if ((s != NULL ? strlen(s) : 0) + sizeof(return_to_continue) +
236 		so_width + se_width + 1 > sc_width)
237 		/*
238 		 * Printing the message has probably scrolled the screen.
239 		 * {{ Unless the terminal doesn't have auto margins,
240 		 *    in which case we just hammered on the right margin. }}
241 		 */
242 		repaint();
243 	flush();
244 }
245 
246 static char intr_to_abort[] = "... (interrupt to abort)";
247 
248 void
ierror(s)249 ierror(s)
250 	char *s;
251 {
252 	lower_left();
253 	clear_eol();
254 	so_enter();
255 	putstr(s);
256 	putstr(intr_to_abort);
257 	so_exit();
258 	flush();
259 }
260