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


NAME


msgdsize - return the number of bytes in a message

SYNOPSIS


#include <sys/stream.h>


size_t msgdsize(mblk_t *mp);


INTERFACE LEVEL


Architecture independent level 1 (DDI/DKI).

PARAMETERS


mp
Message to be evaluated.


DESCRIPTION


The msgdsize() function counts the number of bytes in a data message.
Only bytes included in the data blocks of type M_DATA are included in the
count.

RETURN VALUES


The number of data bytes in a message, expressed as an integer.

CONTEXT


The msgdsize() function can be called from user, interrupt, or kernel
context.

EXAMPLES


See bufcall(9F) for an example that uses msgdsize().

SEE ALSO


bufcall(9F)


Writing Device Drivers


STREAMS Programming Guide


January 16, 2006 MSGDSIZE(9F)