.TH msgdsize() "" "" "DDI/DKI Kernel Routine"
.PC "Get the number of bytes of data that a message holds"
.B "#include <sys/stream.h>"
\fBint msgdsize(\fImessage\^\fB)\fR
\fBmblk_t *\fImessage\^\fB;\fR
.PP
.B msgdsize()
counts and returns the bytes of data within
.IR message .
It counts only the data within message blocks of type
.BR M_DATA .
.SH "See Also"
.B
DDI/DKI kernel routines,
msgb
.R
.SH Notes
.B msgdsize
has base or interrupt level.
It does not sleep.
.PP
A driver can hold a
driver-defined basic lock, read/write lock, or sleep lock
across a call to this function.
