blob: 3700760346ad68e2bfa06dfcdd3ef446496ffac5 (
plain)
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
|
<head>
<title>sendfd(3) - Plan 9 from User Space</title>
<meta content="text/html; charset=utf-8" http-equiv=Content-Type>
</head>
<body bgcolor=#ffffff>
<table border=0 cellpadding=0 cellspacing=0 width=100%>
<tr height=10><td>
<tr><td width=20><td>
<tr><td width=20><td><b>SENDFD(3)</b><td align=right><b>SENDFD(3)</b>
<tr><td width=20><td colspan=2>
<br>
<p><font size=+1><b>NAME </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
sendfd, recvfd – pass file descriptors along Unix domain sockets<br>
</table>
<p><font size=+1><b>SYNOPSIS </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>#include <u.h>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>#include <libc.h>
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>int sendfd(int socket, int fd)
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
</font></tt>
<tt><font size=+1>int recvfd(int socket)<br>
</font></tt>
</table>
<p><font size=+1><b>DESCRIPTION </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<i>Recvfd</i> and <i>sendfd</i> can be used to pass an open file descriptor
over a Unix domain socket from one process to another. Since <a href="../man3/pipe.html"><i>pipe</i>(3)</a>
is implemented with <a href="../man2/socketpair.html"><i>socketpair</i>(2)</a> instead of <a href="../man2/pipe.html"><i>pipe</i>(2)</a>, <i>socket</i> can
be a file descriptor obtained from <a href="../man3/pipe.html"><i>pipe</i>(3)</a>.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
<i>Sendfd</i> sends the file descriptor <i>fd</i> along the socket to a process
calling <i>recvfd</i> on the other end.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
It is assumed that the two sides have coordinated and agreed to
transfer a file descriptor already, so that the <i>sendfd</i> is met
with a <i>recvfd</i> instead of an ordinary <i>read</i>.
<table border=0 cellpadding=0 cellspacing=0><tr height=5><td></table>
The file descriptor number may change on its way between processes,
but the kernel structure it represents will not.<br>
</table>
<p><font size=+1><b>SOURCE </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<tt><font size=+1>/usr/local/plan9/src/lib9/sendfd.c<br>
</font></tt>
</table>
<p><font size=+1><b>SEE ALSO </b></font><br>
<table border=0 cellpadding=0 cellspacing=0><tr height=2><td><tr><td width=20><td>
<a href="../man2/socketpair.html"><i>socketpair</i>(2)</a>, <i>sendmsg</i> in <a href="../man2/send.html"><i>send</i>(2)</a><br>
</table>
<td width=20>
<tr height=20><td>
</table>
<!-- TRAILER -->
<table border=0 cellpadding=0 cellspacing=0 width=100%>
<tr height=15><td width=10><td><td width=10>
<tr><td><td>
<center>
<a href="../../"><img src="../../dist/spaceglenda100.png" alt="Space Glenda" border=1></a>
</center>
</table>
<!-- TRAILER -->
</body></html>
|