unlinkb(9F)						   Kernel Functions for Drivers 					       unlinkb(9F)

NAME

       unlinkb - remove a message block from the head of a message

SYNOPSIS

       #include <sys/stream.h>

       mblk_t *unlinkb(mblk_t *mp);

INTERFACE LEVEL

       Architecture independent level 1 (DDI/DKI).

PARAMETERS

       mp	Pointer to the message.

DESCRIPTION

       unlinkb() removes the first message block from the message pointed to by  mp. A new message, minus the removed message block, is returned.

RETURN VALUES

       If  successful,	unlinkb() returns a pointer to the message with the first message block removed. If there is only one message block in the
       message, NULL is returned.

CONTEXT

       unlinkb() can be called from user or interrupt context.

EXAMPLES

       Example 1: unlinkb() example

       The routine expects to get passed an  M_PROTO T_DATA_IND message.  It will remove and free the  M_PROTO header  and  return  the  remaining
       M_DATA portion of the message.

	1  mblk_t *
	2  makedata(mp)
	3      mblk_t *mp;
	4  {
	5   mblk_t *nmp;
	6
	7   nmp = unlinkb(mp);
	8   freeb(mp);
	9   return(nmp);
       10  }

SEE ALSO

       linkb(9F)

       Writing Device Drivers

       STREAMS Programming Guide

SunOS 5.10							    11 Apr 1991 						       unlinkb(9F)