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

       The  unlinkb()  function 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, the unlinkb() function 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

       The unlinkb() function can be called from user, interrupt, or kernel 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 5.11							    16 Jan 2006 						       unlinkb(9F)