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rmvb(9f) [sunos man page]

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

NAME
rmvb - 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
rmvb() 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
rmvb() can be called from user or interrupt context. 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 message (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 ALSO
freeb(9F), msgb(9S) Writing Device Drivers STREAMS Programming Guide SunOS 5.10 11 Apr 1991 rmvb(9F)

Check Out this Related Man Page

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

NAME
copymsg - copy a message SYNOPSIS
#include <sys/stream.h> mblk_t *copymsg(mblk_t *mp); INTERFACE LEVEL
Architecture independent level 1 (DDI/DKI). PARAMETERS
mp Pointer to the message to be copied. DESCRIPTION
copymsg() forms a new message by allocating new message blocks, and copying the contents of the message referred to by mp (using the copyb(9F) function). It returns a pointer to the new message. RETURN VALUES
If the copy is successful, copymsg() returns a pointer to the new message. Otherwise, it returns a NULL pointer. CONTEXT
copymsg() can be called from user or interrupt context. EXAMPLES
Example 1: : Using copymsg The routine lctouc() converts all the lowercase ASCII characters in the message to uppercase. If the reference count is greater than one (line 8), then the message is shared, and must be copied before changing the contents of the data buffer. If the call to the copymsg() function fails (line 9), return NULL (line 10), otherwise, free the original message (line 11). If the reference count was equal to 1, the message can be modified. For each character (line 16) in each message block (line 15), if it is a lowercase letter, convert it to an upper- case letter (line 18). A pointer to the converted message is returned (line 21). 1 mblk_t *lctouc(mp) 2 mblk_t *mp; 3 { 4 mblk_t *cmp; 5 mblk_t *tmp; 6 unsigned char *cp; 7 8 if (mp->b_datap->db_ref > 1) { 9 if ((cmp = copymsg(mp)) == NULL) 10 return (NULL); 11 freemsg(mp); 12 } else { 13 cmp = mp; 14 } 15 for (tmp = cmp; tmp; tmp = tmp->b_cont) { 16 for (cp = tmp->b_rptr; cp < tmp->b_wptr; cp++) { 17 if ((*cp <= 'z') && (*cp >= 'a')) 18 *cp -= 0x20; 19 } 20 } 21 return(cmp); 22 } SEE ALSO
allocb(9F), copyb(9F), msgb(9S) Writing Device Drivers STREAMS Programming Guide SunOS 5.10 27 Jun 1995 copymsg(9F)

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