1 /* $OpenBSD: screen.c,v 1.22 2019/10/08 07:26:59 kn Exp $ */
2
3 /*
4 * Top users/processes display for Unix
5 * Version 3
6 *
7 * Copyright (c) 1984, 1989, William LeFebvre, Rice University
8 * Copyright (c) 1989, 1990, 1992, William LeFebvre, Northwestern 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 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR OR HIS EMPLOYER BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 /*
32 * This file contains the routines that interface to termcap and stty/gtty.
33 *
34 * Paul Vixie, February 1987: converted to use ioctl() instead of stty/gtty.
35 *
36 * I put in code to turn on the TOSTOP bit while top was running, but I didn't
37 * really like the results. If you desire it, turn on the preprocessor
38 * variable "TOStop". --wnl
39 */
40
41 #include <sys/types.h>
42 #include <sys/ioctl.h>
43 #include <curses.h>
44 #include <err.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <term.h>
48 #include <unistd.h>
49 #include <stdbool.h>
50
51 #include "top.h"
52 #include "screen.h"
53 #include "layout.h"
54
55 int screen_length, screen_width;
56 char ch_erase, ch_kill, smart_terminal;
57
58 static struct termios old_settings, new_settings;
59 static char is_a_terminal = false;
60
61 void
init_termcap(int interactive)62 init_termcap(int interactive)
63 {
64 char *term_name;
65 int status;
66
67 /* set defaults in case we aren't smart */
68 screen_width = MAX_COLS;
69 screen_length = 0;
70
71 if (!interactive) {
72 /* pretend we have a dumb terminal */
73 smart_terminal = false;
74 return;
75 }
76 /* assume we have a smart terminal until proven otherwise */
77 smart_terminal = true;
78
79 /* get the terminal name */
80 term_name = getenv("TERM");
81
82 /* if there is no TERM, assume it's a dumb terminal */
83 /* patch courtesy of Sam Horrocks at telegraph.ics.uci.edu */
84 if (term_name == NULL) {
85 smart_terminal = false;
86 return;
87 }
88
89 /* now get the termcap entry */
90 if ((status = tgetent(NULL, term_name)) != 1) {
91 if (status == -1)
92 warnx("can't open termcap file");
93 else
94 warnx("no termcap entry for a `%s' terminal", term_name);
95
96 /* pretend it's dumb and proceed */
97 smart_terminal = false;
98 return;
99 }
100
101 /* "hardcopy" immediately indicates a very stupid terminal */
102 if (tgetflag("hc")) {
103 smart_terminal = false;
104 return;
105 }
106
107 /* set up common terminal capabilities */
108 if ((screen_length = tgetnum("li")) <= y_procs) {
109 screen_length = smart_terminal = 0;
110 return;
111 }
112
113 /* screen_width is a little different */
114 if ((screen_width = tgetnum("co")) == -1)
115 screen_width = 79;
116 else
117 screen_width -= 1;
118
119 /* get necessary capabilities */
120 if (tgetstr("cl", NULL) == NULL || tgetstr("cm", NULL) == NULL) {
121 smart_terminal = false;
122 return;
123 }
124
125 /* get the actual screen size with an ioctl, if needed */
126 /*
127 * This may change screen_width and screen_length, and it always sets
128 * lower_left.
129 */
130 get_screensize();
131
132 /* if stdout is not a terminal, pretend we are a dumb terminal */
133 if (tcgetattr(STDOUT_FILENO, &old_settings) == -1)
134 smart_terminal = false;
135 }
136
137 void
init_screen(void)138 init_screen(void)
139 {
140 /* get the old settings for safe keeping */
141 if (tcgetattr(STDOUT_FILENO, &old_settings) != -1) {
142 /* copy the settings so we can modify them */
143 new_settings = old_settings;
144 /* turn off ICANON, character echo and tab expansion */
145 new_settings.c_lflag &= ~(ICANON | ECHO);
146 new_settings.c_oflag &= ~(OXTABS);
147 new_settings.c_cc[VMIN] = 1;
148 new_settings.c_cc[VTIME] = 0;
149
150 (void) tcsetattr(STDOUT_FILENO, TCSADRAIN, &new_settings);
151 /* remember the erase and kill characters */
152 ch_erase = old_settings.c_cc[VERASE];
153 ch_kill = old_settings.c_cc[VKILL];
154
155 is_a_terminal = true;
156 #if 0
157 /* send the termcap initialization string */
158 putcap(terminal_init);
159 #endif
160 }
161 if (!is_a_terminal) {
162 /* not a terminal at all---consider it dumb */
163 smart_terminal = false;
164 }
165
166 if (smart_terminal)
167 initscr();
168 }
169
170 void
end_screen(void)171 end_screen(void)
172 {
173 if (smart_terminal) {
174 move(screen_length-1, 0);
175 clrtoeol();
176 refresh();
177 endwin();
178 }
179 if (is_a_terminal)
180 (void) tcsetattr(STDOUT_FILENO, TCSADRAIN, &old_settings);
181 }
182
183 void
reinit_screen(void)184 reinit_screen(void)
185 {
186 #if 0
187 /* install our settings if it is a terminal */
188 if (is_a_terminal)
189 (void) tcsetattr(STDOUT_FILENO, TCSADRAIN, &new_settings);
190
191 /* send init string */
192 if (smart_terminal)
193 putcap(terminal_init);
194 #endif
195 }
196
197 void
get_screensize(void)198 get_screensize(void)
199 {
200 struct winsize ws;
201
202 if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) != -1) {
203 if (ws.ws_row != 0)
204 screen_length = ws.ws_row;
205 if (ws.ws_col != 0)
206 screen_width = ws.ws_col - 1;
207 }
208 }
209
210 void
go_home(void)211 go_home(void)
212 {
213 if (smart_terminal) {
214 move(0, 0);
215 refresh();
216 }
217 }
218