'\" te
.\"  Copyright 1989 AT&T
.\"  Copyright (c) 2006, Sun Microsystems, Inc.,  All Rights Reserved
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.TH PTOB 9F "Jan 16, 2006"
.SH NAME
ptob \- convert size in pages to size in bytes
.SH SYNOPSIS
.LP
.nf
#include <sys/ddi.h>



\fBunsigned long\fR \fBptob\fR(\fBunsigned long\fR \fInumpages\fR);
.fi

.SH INTERFACE LEVEL
.sp
.LP
Architecture independent level 1 (DDI/DKI).
.SH PARAMETERS
.sp
.ne 2
.na
\fB\fInumpages\fR\fR
.ad
.RS 12n
Size in number of pages to convert to size in bytes.
.RE

.SH DESCRIPTION
.sp
.LP
This function returns the number of bytes that are contained in the specified
number of pages. For example, if the page size is 2048, then \fBptob(2)\fR
returns \fB4096\fR. \fBptob(0)\fR returns \fB0\fR.
.SH RETURN VALUES
.sp
.LP
The return value is always the number of bytes in the specified number of
pages. There are no invalid input values, and no checking will be performed for
overflow in the case of a page count whose corresponding byte count cannot be
represented by an \fBunsigned long\fR. Rather, the higher order bits will be
ignored.
.SH CONTEXT
.sp
.LP
The \fBptob()\fR function can be called from user, interrupt, or kernel
context.
.SH SEE ALSO
.sp
.LP
\fBbtop\fR(9F), \fBbtopr\fR(9F), \fBddi_ptob\fR(9F)
.sp
.LP
\fIWriting Device Drivers\fR