.TH MDEX_DEL 3 2023-06-20 "LIBRECAST" "Librecast Programmer's Manual"
.SH NAME
mdex_del \- delete an entry from a multicast index
.SH LIBRARY
Librecast library
.RI ( liblibrecast ", " \-llibrecast )
.SH SYNOPSIS
.nf
.B #include <librecast/mdex.h>
.PP
.BI "int mdex_del(mdex_t " *mdex ", unsigned char " *hash ", size_t " hashlen ");"
.fi
.PP
Compile and link with \fI\-llibrecast\fP.
.SH DESCRIPTION
The
.BR mdex_del
function deletes an entry from the multicast index
.IR mdex
using
.IR hash
(of length
.IR hashlen )
as the key.
If no matching entry is found in the index, -1 is returned and errno is set to
.BR ENOENT .
.PP
.IR hashlen
can be shorter than the full length of the hash stored with
.BR mdex_put (3)
and will delete the first entry matching the truncated hash.
This allows us to store the full 32 byte hash in the index, but still match against the
truncated hash derived from, say, the 14 bytes of an IPv6 multicast group
address.
.SH RETURN VALUE
.BR mdex_put ()
returns zero on success.
On error, \-1 is returned, and
.I errno
is set to indicate the error.
.SH ERRORS
.TP
.BR EINVAL
Invalid argument. Both
.IR mdex
and
.IR hash
are required (not NULL), and
.IR hashlen
> 0.
.PP
.BR ENOENT
No entry found matching
.IR hash .
.SH SEE ALSO
.BR mdex_init (3),
.BR mdex_free (3),
.BR mdex_get (3),
.BR mdex_put (3),
.BR lc_share (3)