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
|
.\" Ouroboros man pages CC-BY 2017 - 2021
.\" Dimitri Staessens <dimitri@ouroboros.rocks>
.\" Sander Vrijders <sander@ouroboros.rocks>
.TH FLOW_READ 3 2017-04-10 Ouroboros "Ouroboros Programmer's Manual"
.SH NAME
flow_read, flow_write \- read and write from/to a flow
.SH SYNOPSIS
.B #include <ouroboros/dev.h>
\fBssize_t flow_read(int \fIfd\fB, void * \fIbuf\fB, size_t \fIcount\fB);\fR
\fBssize_t flow_write(int \fIfd\fB, const void * \fIbuf\fB, size_t \fIcount\fB);\fR
Compile and link with \fI-louroboros-dev\fR.
.SH DESCRIPTION
The \fBflow_read\fR() function attempts to read at most \fIcount\fR
bytes from the flow associated with the allocated flow descriptor
\fIfd\fR into the buffer pointed to by buf.
The \fBflow_write\fR() function attempts to write \fIcount\fR bytes
from the supplied buffer \fIbuf\fR to the flow specified by \fIfd\fR.
.SH RETURN VALUE
On success, \fBflow_read\fR() returns the number of bytes read. On
failure, a negative value indicating the error will be
returned. Partial reads are enabled by default. If the number of bytes
read equals count, a subsequent call to \fBflow_read\fR() should be
performed to check if there were more bytes to read. This call to
\fBflow_read\fR will return 0 if there was no more data and mark the
end of the datagram.
On success, \fBflow_write\fR() returns the number of bytes written. On
failure, a negative value indicating the error will be returned.
Partial writes needs to be explicitly enabled. Passing a
NULL pointer for \fIbuf\fR returns 0 with no other effects.
.SH ERRORS
.B -EINVAL
An invalid argument was passed.
.B -EIRMD
Failed to contact an IRMd instance.
.B -EBADF
Invalid flow descriptor passed.
.B -ENOTALLOC
The flow was not allocated.
.B -EFLOWDOWN
The flow has been reported down.
.B -EFLOWPEER
The flow's peer is unresponsive (flow timed out).
.B -EMSGSIZE
The buffer was too large to be written.
.SH ATTRIBUTES
For an explanation of the terms used in this section, see \fBattributes\fR(7).
.TS
box, tab(&);
LB|LB|LB
L|L|L.
Interface & Attribute & Value
_
\fBflow_read\fR() & Thread safety & MT-Safe
_
\fBflow_write\fR() & Thread safety & MT-Safe
.TE
.SH TERMINOLOGY
Please see \fBouroboros-glossary\fR(7).
.SH SEE ALSO
.BR fccntl "(3), " flow_alloc "(3), " fqueue "(3), " fset "(3), " \
ouroboros (8)
.SH COLOPHON
This page is part of the Ouroboros project, found at
http://ouroboros.rocks
These man pages are licensed under the Creative Commons Attribution
4.0 International License. To view a copy of this license, visit
http://creativecommons.org/licenses/by/4.0/
|
