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
|
/****************************************************************
*
* Purpose: Basic example of pipe.
* Read and write fixed length records across a pipe.
* This is about a simple as they come...
*
* Author: M J Leslie
*
* Date: 17 Apr 96
*
****************************************************************/
#include <sys/types.h>
#include <unistd.h> /* pipe. */
#include <signal.h>
void Child (pid_t Handle);
void Parent (pid_t Handle);
main()
{
pid_t Pid;
int fd[2];
pipe(fd); /* Create two file descriptors */
Pid = fork();
if ( Pid == 0) /* Child */
{
close(fd[0]);
Child(fd[1]);
puts("Child end");
}
else /* Parent. */
{
close(fd[1]);
Parent(fd[0]);
puts("Parent end");
}
}
/****************************************************************
*
* The Child sends data to the parent.
*
****************************************************************/
void Child(pid_t Handle)
{
char Buff[]="Martin 1 abcdefghijklmnop ";
write(Handle, Buff, strlen(Buff)+1);
Buff[7] = '2';
write(Handle, Buff, strlen(Buff)+1);
Buff[7] = '3';
write(Handle, Buff, strlen(Buff)+1);
Buff[7] = '4';
write(Handle, Buff, strlen(Buff)+1);
close(Handle);
}
/****************************************************************
*
* Read the data sent by the child.
*
****************************************************************/
void Parent(pid_t Handle)
{
char Buff[50];
/* ... Read EXACTLY the number of bytes sent.
... 0 is returned when the pipe is closed by the child. */
while (read(Handle,Buff, 27) > 0)
{
printf("%s\n", Buff);
}
}
|
