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Annotated edit history of writev(3) version 1, including all changes. View license author blame.
Rev Author # Line
1 perry 1 READV
2 !!!READV
3 NAME
4 SYNOPSIS
5 DESCRIPTION
6 RETURN VALUE
7 ERRORS
8 CONFORMING TO
9 BUGS
10 SEE ALSO
11 ----
12 !!NAME
13
14
15 readv, writev - read or write data into multiple buffers
16 !!SYNOPSIS
17
18
19 __#include
20 __ ''filedes''__, const struct iovec *__''vector''__,
21 size_t__ ''count''__);
22 int writev(int__ ''filedes''__, const struct iovec *__''vector''__,
23 size_t__ ''count''__);
24 __
25 !!DESCRIPTION
26
27
28 The __readv()__ function reads ''count'' blocks from
29 the file associated with the file descriptor ''filedes''
30 into the multiple buffers described by
31 ''vector''.
32
33
34 The __writev()__ function writes at most ''count''
35 blocks described by ''vector'' to the file associated
36 with the file descriptor ''filedes''.
37
38
39 The pointer ''vector'' points to a __struct iovec__
40 defined in ____ as
41
42
43 struct iovec {
44 void *iov_base; /* Starting address */
45 size_t iov_len; /* Number of bytes */
46 };
47 Buffers are processed in the order ''vector[[0]'', ''vector[[1]'', ... ''vector[[count]''.
48
49
50 The __readv()__ function works just like read(2)
51 except that multiple buffers are filled.
52
53
54 The __writev()__ function works just like write(2)
55 except that multiple buffers are written out.
56 !!RETURN VALUE
57
58
59 The __readv()__ function returns the number of bytes or
60 -1 on error; the __writev()__ function returns the number
61 of bytes written.
62 !!ERRORS
63
64
65 The __readv()__ and __writev()__ functions can fail
66 and set ''errno'' to the following values:
67
68
69 __EBADF__
70
71
72 ''fd'' is not a valid file descriptor.
73
74
75 __EINVAL__
76
77
78 ''fd'' is unsuitable for reading (for __readv()__) or
79 writing (for __writev()__).
80
81
82 __EFAULT__
83
84
85 ''buf'' is outside the processes' address
86 space.
87
88
89 __EAGAIN__
90
91
92 Non-blocking I/O had been selected in the __open()__
93 call, and reading or writing could not be done
94 immediately.
95
96
97 __EINTR__
98
99
100 Reading or writing was interrupted before any data was
101 transferred.
102 !!CONFORMING TO
103
104
105 unknown
106 !!BUGS
107
108
109 It is not advisable to mix calls to functions like
110 __readv()__ or __writev()__, which operate on file
111 descriptors, with the functions from the stdio library; the
112 results will be undefined and probably not what you
113 want.
114 !!SEE ALSO
115
116
117 read(2), write(2)
118 ----
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