X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~mdw/git/mLib/blobdiff_plain/dd3c57bc8cac59e0d657ee665ce462988d27d714..18c831dcd0ae4d660c70ccac69d27ed2a97851be:/sys/fdpass.3

diff --git a/sys/fdpass.3 b/sys/fdpass.3
new file mode 100644
index 0000000..b643bde
--- /dev/null
+++ b/sys/fdpass.3
@@ -0,0 +1,54 @@
+.\" -*-nroff-*-
+.TH fdpass 3 "28 November 2003" "Straylight/Edgeware" "mLib utilities library"
+.SH NAME
+fdpass \- file descriptor passing
+.\" @fdpass_send
+.\" @fdpass_recv
+.SH SYNOPSIS
+.nf
+.B "#include <mLib/fdpass.h>"
+
+.BI "ssize_t fdpass_send(int " sock ", int " fd ", const void *" p ", size_t " sz );
+.BI "ssize_t fdpass_recv(int " sock ", int *" fd ", void *" p ", size_t " sz );
+.fi
+.SH DESCRIPTION
+The function
+.B fdpass_send
+sends the file descriptor
+.I fd
+as ancillary data attached to the buffer pointed to by
+.I p
+of length
+.I sz
+over the Unix-domain socket
+.IR sock .
+It returns the amount of data sent, or \-1 on error.  For more details,
+see
+.BR sendmsg (2)
+and
+.BR unix (7).
+.PP
+The function
+.B fdpass_recv
+receives at most
+.I sz
+bytes of data into the buffer pointed to by
+.IR p ,
+together with at most one file descriptor passed as ancillary data,
+which is written to the integer pointed to by
+.IR fd .
+Other file descriptors received are closed; any other ancillary messages
+are ignored.  If no file descriptor is received,
+.BI * fd
+is set to \-1.  The function returns the number of bytes read, or \-1 on
+error.  For more details, see
+.BR recvmsg (2)
+and
+.BR unix (7).
+.SH "SEE ALSO"
+.BR recvmsg (2),
+.BR sendmsg (2),
+.BR mLib (3),
+.BR unix (7).
+.SH AUTHOR
+Mark Wooding, <mdw@distorted.org.uk>