rmvb(9F) Kernel Functions for Drivers rmvb(9F)NAMErmvb - remove a message block from a message
SYNOPSIS
#include <sys/stream.h>
mblk_t *rmvb(mblk_t *mp, mblk_t *bp);
INTERFACE LEVEL
Architecture independent level 1 (DDI/DKI).
PARAMETERS
mp Message from which a block is to be removed. mblk_t is an
instance of the msgb(9S) structure.
bp Message block to be removed.
DESCRIPTION
The rmvb() function removes a message block (bp) from a message (mp),
and returns a pointer to the altered message. The message block is not
freed, merely removed from the message. It is the module or driver's
responsibility to free the message block.
RETURN VALUES
If successful, a pointer to the message (minus the removed block) is
returned. The pointer is NULL if bp was the only block of the message
before rmvb() was called. If the designated message block (bp) does
not exist, -1 is returned.
CONTEXT
The rmvb() function can be called from user, interrupt, or kernel con‐
text.
EXAMPLES
This routine removes all zero-length M_DATA message blocks from the
given message. For each message block in the message, save the next
message block (line 10). If the current message block is of type M_DATA
and has no data in its buffer (line 11), then remove it from the mes‐
sage (line 12) and free it (line 13). In either case, continue with the
next message block in the message (line 16).
1 void
2 xxclean(mp)
3 mblk_t *mp;
4 {
5 mblk_t *tmp;
6 mblk_t *nmp;
7
8 tmp = mp;
9 while (tmp) {
10 nmp = tmp->b_cont;
11 if ((tmp->b_datap->db_type == M_DATA) &&
(tmp->b_rptr == tmp->b_wptr)) {
12 (void) rmvb(mp, tmp);
13 freeb(tmp);
14 }
15 tmp = nmp;
16 }
17 }
SEE ALSOfreeb(9F), msgb(9S)
Writing Device Drivers
STREAMS Programming Guide
SunOS 5.10 16 Jan 2006 rmvb(9F)
