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
|
#include <sys/ioctl.h>
#include <stdio.h>
main(argc, argv)
int argc;
char **argv;
{
struct sgttyb sgo, sgn;
struct tchars tco, tcn;
if (argc < 2) {
fprintf(stderr, "Usage: %s file [file ...]\n", *argv);
exit(1);
}
/*
* In real life we'd check the return values of
* these, since if the input is redirected from
* a file they will fail. We are assuming the
* terminal is always connected to the standard
* input.
*/
ioctl(0, TIOCGETP, &sgo);
ioctl(0, TIOCGETC, &tco);
sgn = sgo;
sgn.sg_flags &= ~ECHO; /* turn off ECHO */
sgn.sg_flags |= CBREAK; /* turn on CBREAK */
tcn = tco;
tcn.t_intrc = -1; /* disable int key */
/*
* Set the new modes. Again we ignore return
* values.
*/
ioctl(0, TIOCSETP, &sgn);
ioctl(0, TIOCSETC, &tcn);
while (--argc)
more(*++argv);
/*
* Reset the old tty modes.
*/
ioctl(0, TIOCSETP, &sgo);
ioctl(0, TIOCSETC, &tco);
exit(0);
}
/*
* more--display the file.
*/
more(file)
char *file;
{
FILE *fp;
int line;
char linebuf[1024];
if ((fp = fopen(file, "r")) == NULL) {
perror(file);
return;
}
/*
* Print 22 lines at a time.
*/
for (;;) {
line = 1;
while (line < 22) {
/*
* If end-of-file, let them hit a key one
* more time and then go back.
*/
if (fgets(linebuf, sizeof(linebuf), fp) == NULL) {
fclose(fp);
prompt();
return;
}
fwrite(linebuf, 1, strlen(linebuf), stdout);
line++;
}
prompt();
}
}
/*
* prompt--prompt for a character.
*/
prompt()
{
char answer;
printf("Type any character for next page: ");
answer = getchar();
putchar('\n');
}
|
