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| <tr><td width=20><td><b>SENDFD(3)</b><td align=right><b>SENDFD(3)</b> |
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| <p><font size=+1><b>NAME </b></font><br> |
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| sendfd, recvfd – pass file descriptors along Unix domain sockets<br> |
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| <p><font size=+1><b>SYNOPSIS </b></font><br> |
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| <tt><font size=+1>#include <u.h> |
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| <tt><font size=+1>#include <libc.h> |
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| <tt><font size=+1>int sendfd(int socket, int fd) |
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| <tt><font size=+1>int recvfd(int socket)<br> |
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| <p><font size=+1><b>DESCRIPTION </b></font><br> |
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| <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>. |
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| <i>Sendfd</i> sends the file descriptor <i>fd</i> along the socket to a process |
| calling <i>recvfd</i> on the other end. |
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| 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>. |
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| The file descriptor number may change on its way between processes, |
| but the kernel structure it represents will not.<br> |
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| <p><font size=+1><b>SOURCE </b></font><br> |
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| <tt><font size=+1>/usr/local/plan9/src/lib9/sendfd.c<br> |
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| <p><font size=+1><b>SEE ALSO </b></font><br> |
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| <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> |
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