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
|
includefile(include/header)
COMMENT(manpage, section, releasedate, archive, short name)
manpage(FBB::Pipe)(3bobcat)(_CurYrs_)(libbobcat1-dev__CurVers_-x.tar.gz)
(Error handler)
manpagename(FBB::Pipe)(Defines a system level pipe)
manpagesynopsis()
bf(#include <bobcat/pipe>)nl()
Linking option: tt(-lbobcat)
manpagedescription()
bf(FBB::Pipe) objects may be used to construct a em(pipe). bf(FBB::Pipe)
objects offer a simple interface to the reading and writing ends of
pipes. bf(FBB::Pipe) objects are object-wrappers around the bf(pipe)(2) system
call.
includefile(include/namespace)
manpagesection(INHERITS FROM)
-
manpagesection(CONSTRUCTORS)
itemization(
itb(Pipe())
The default bf(Pipe()) constructor constructs a basic pipe, calling
bf(pipe)(2).
This constructor throws an tt(Errno) exception if the default bf(Pipe)
constructor did not properly complete. The thrown bf(Errno) object's
tt(which()) member shows the system's tt(errno) value set by the failing
bf(pipe)(2) function.
itb(Pipe(int const *fd))
This constructor expects two file descriptors, which already define a
pipe, stored at tt(fd). Following the construction of the tt(Pipe) object
the array at by tt(fd) is no longer used by the tt(Pipe) object.
)
The copy constructor is available.
Note that when the pipe goes out of scope, no bf(close)(2) operation is
performed on the pipe's ends. If the pipe should be closed by the desctructor,
derive a class from bf(Pipe)(3bobcat), whose destructor performs the required
closing-operation.
manpagesection(MEMBER FUNCTIONS)
itemization(
itb(int readFd() const)
Returns the pipe's file descriptor that is used for reading
itb(void readFrom(int filedescriptor))
Sets up redirection from the internal em(read) filedescriptor to the
given filedescriptor: information is read from the bf(FBB::Pipe) object when
reading from the provided filedescriptor.
itb(void readFrom(int const *filedescriptors, size_t n))
Sets up redirection from the internal em(read) filedescriptor to the
given filedescriptors: information is read from the bf(FBB::Pipe) object when
reading from any of the bf(n) provided filedescriptors (experimental).
itb(int readOnly())
Closes the writing end of the pipe, returns the reading end's file
descriptor.
itb(void verify() const)
Obsoleted, will be removed in a future Bobcat release.
itb(int writeFd() const)
Returns the pipe's file descriptor that is used for writing
itb(void writtenBy(int filedescriptor))
Sets up redirection from the internal em(write) filedescriptor to the
given filedescriptor: information is written to the bf(FBB::Pipe) object when
writing to the provided filedescriptor.
itb(void writtenBy(int const *filedescriptors, size_t n))
Sets up redirection from the internal em(write) filedescriptor to the
given filedescriptors: information is written to the bf(FBB::Pipe) object
when writing to each of the bf(n) provided filedescriptors.
itb(int writeOnly())
Closes the reading end of the pipe, returns the writing end's file
descriptor.
)
manpagesection(PROTECTED ENUMERATION)
The bf(RW) protected enumeration has the following elements:
itemization(
itb(READ)
The index in bf(d_fd[]) (see below) of the element holding the pipe's
reading file descriptor;
itb(WRITE)
The index in bf(d_fd[]) (see below) of the element holding the pipe's
writing file descriptor
)
manpagesection(PROTECTED DATA)
itemization(
itb(int d_fd[2])
The array holding the pipe's file descriptors. The bf(READ) element
contains the pipe's reading file descriptor, the bf(WRITE) element
contains the pipe's writing file descriptor,
)
manpagesection(EXAMPLE)
verb(
#include <bobcat/pipe>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <iostream>
#include <string>
using namespace std;
using namespace FBB;
int main()
{
Pipe p; // construct a pipe
cout << "Read file descriptor: " << p.getReadFd() << endl;
cout << "Write file descriptor: " << p.getWriteFd() << endl;
int pid = fork();
if (pid == -1)
return 1;
if (!pid) //child
{
p.readFrom(STDIN_FILENO); // read what goes into the pipe
string s;
getline(cin, s);
cout << "CHILD: Got `" << s << "'" << endl;
getline(cin, s);
cout << "CHILD: Got `" << s << "'" << endl;
return 0;
}
p.writtenBy(STDOUT_FILENO); // write to the pipe via cout
cout << "first line" << endl;
cout << "second line" << endl;
waitpid(pid, 0, 0);
return 0;
}
)
manpagefiles()
em(bobcat/pipe) - defines the class interface
manpageseealso()
bf(bobcat)(7), bf(pipe)(2), bf(mkfifo)(3)
manpagebugs()
Note that when the pipe goes out of scope, no bf(close)(2) operation is
performed on the pipe's ends. If the pipe should be closed by the desctructor,
derive a class from bf(Pipe)(3bobcat), whose destructor performs the required
closing-operation.
includefile(include/trailer)
|
