1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
|
/*
**********************************************************************
* File io.c
**********************************************************************
*
* Non blocking input routine
* Works by puttng the terminal in CBREAK mode and using the FIONREAD
* ioctl call to determine the number of characters in the input queue
*/
#include "stdio.h"
#include "io.h"
#include <sys/types.h>
#include <sys/time.h>
#include <signal.h>
#include <sgtty.h>
#include "cext.h"
int IOinputfd; /* input file descriptor (usually 0) */
int IOnochar; /* Value to be returned by IOgetchar()
where there is no input to be had */
static struct sgttyb IOoldmodes, IOcurrentmodes;
/* Initial and current tty modes */
/*
* IOsetup(inputfd)
* Args:
* inputfd - input file descriptor (should be zero for standard input)
* Returns:
* 0 - if all goes well
* -1 - if an ioctl fails (also calls perror)
* Side Effects:
* Puts the terminal in CBREAK mode - before process termination
* IOcleanup() should be called to restore old terminal modes
* Catch's interrupts (if they are not already being caught) and
* calls IOcleanup before exiting
*
*/
#define ERROR(s) return (perror(s), -1)
IOsetup(inputfd)
{
static IOdiegracefully();
int (*interrupt_handler)();
IOinputfd = inputfd;
IOnochar = NOCHAR;
if(ioctl(IOinputfd, TIOCGETP, &IOoldmodes) < 0)
ERROR("IOsetup");
IOcurrentmodes = IOoldmodes;
IOcurrentmodes.sg_flags |= CBREAK;
IOcurrentmodes.sg_flags &= ~ECHO;
if(ioctl(IOinputfd, TIOCSETP, &IOcurrentmodes))
ERROR("IOsetup-2");
if( (interrupt_handler = signal(SIGINT, IOdiegracefully)) != 0)
signal(SIGINT, interrupt_handler);
return 0;
}
static
IOdiegracefully()
{
write(2, "\nBye\n", 5);
IOcleanup();
EXIT(2);
}
/*
* IOcleanup()
* Returns:
* 0 - if all goes well
* -1 - if an ioctl fails (also calls perror)
* Side Effects:
* Restores initial terminal modes
*/
IOcleanup()
{
if(ioctl(IOinputfd, TIOCSETP, &IOoldmodes) < 0)
ERROR("IOclean");
return 0;
}
/*
* IOgetchar()
* Returns:
* A character off the input queue if there is one,
* IOnochar if there is no character waiting to be read,
* -1 if an ioctl fails (shouldn't happen if IOsetup went OK)
*/
#ifndef UNIX_MACH
IOgetchar()
{
int n;
char c;
if(ioctl(IOinputfd, FIONREAD, &n) < 0)
ERROR("IOgetchar");
if(n <= 0)
return IOnochar;
switch(read(IOinputfd, &c, 1)) {
case 1:
return c;
case 0:
return EOF;
default:
ERROR("IOgetchar-read");
}
}
#ifdef IOGETCHAR2
IOgetchar2()
{
int nfds, readfds = 1 << IOinputfd;
char c;
static struct timeval zero;
if(IOinputfd < 0 || IOinputfd >= 32) {
printf("IOgetchar2: bad IOinputfd (%d)%s\n", IOinputfd,
IOinputfd == -1 ? "Did you call IOsetup(fd)?" : "");
}
nfds = select(32, &readfds, 0, 0, &zero);
if(nfds > 0) {
switch(read(IOinputfd, &c, 1)) {
case 0:
return EOF;
case 1:
return c;
default:
printf("IOgetchar2: read failed!\n");
return NOCHAR;
}
}
else if(nfds < 0)
printf("IOgetchar2: select failed!\n");
return NOCHAR;
}
#endif
/*
* IOwaitchar()
* Returns:
* A character off the input queue. Waits if necessary.
*/
int IOwaitchar()
{
char c;
if (read(IOinputfd, &c, 1) == 1) return c;
else return EOF;
}
#endif /* not UNIX_MACH */
|
