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.TH EVS_JOIN 3 2004-08-31 "corosync Man Page" "Corosync Cluster Engine Programmer's Manual"
.SH NAME
evs_join \- Joins one or more groups in the EVS library
.SH SYNOPSIS
.B #include <corosync/evs.h>
.sp
.BI "int evs_join(evs_handle_t " handle ", evs_group_t *" groups ", int " group_entries ");
.SH DESCRIPTION
The
.B evs_join
function is used to join one or more groups.  When a group is joined, using the
.B evs_mcast_joined(3)
function will multicast to the groups joined in the argument
.I handle.
Messages that are sent to any of the groups joined to the parameter
.I handle
will be delivered by
.B evs_dispatch(3).
.PP
This call may be used more then once on a handle, in which case the joined groups will
be all of the groups passed to the
.B evs_join(3)
function during the lifecycle of the parameter
.I handle.
.PP

The argument
.I groups
is used to specify the groups to join.  A group is a 32 byte key.  The key is
not a string, hence, the entire key is used when joining the channel.  For that reason
the entire group should be initialized.
.PP
The argument
.I group_entries
specifies how many entries are located in the groups argument.

The
.I groups
argument is of the type evs_group_t which is defined by the structure:

.IP
.RS
.ne 18
.nf
.ta 4n 30n 33n
typedef struct {
        char key[32];
} evs_groups_t;
.ta
.fi
.RE
.IP
.PP
.PP
.SH RETURN VALUE
This call returns the EVS_OK value if successful, otherwise an error is returned.
.PP
.SH ERRORS
The errors are undocumented.
.SH "SEE ALSO"
.BR evs_overview (8),
.BR evs_initialize (3),
.BR evs_finalize (3),
.BR evs_fd_get (3),
.BR evs_dispatch (3),
.BR evs_leave (3),
.BR evs_mcast_joined (3),
.BR evs_mcast_groups (3),
.BR evs_mmembership_get (3)
.BR evs_context_get (3)
.BR evs_context_set (3)
.PP