CTOD(9) BSD Kernel Developer's Manual CTOD(9)NAMEctod — macros related to bytes, pages, and disk blocks
SYNOPSIS
#include <sys/param.h>
size
ctod(size x);
size
dtoc(size x);
size
ctob(size x);
size
btoc(size x);
size
dbtob(size x);
size
btodb(size x);
DESCRIPTION
The ctod family of macros can be used to convert between bytes, pages
(“clicks”), and disk blocks.
The following table lists the possible conversions:
Macro From To
ctod() pages disk blocks
dtoc() disk blocks pages
ctob() pages bytes
btoc() bytes pages
dbtob() disk blocks bytes
btodb() bytes disk blocks
These are typical macros that may appear with different names in other
operating systems. Examples include btop() and btopr() in Solaris.
SEE ALSOparam(3)HISTORY
Some of these macros appeared in Version 7 AT&T UNIX.
CAVEATS
The described macros make no assumptions about the type of the input
parameter. A caller should ensure that neither integer overflow nor
integer underflow are possible.
BSD April 8, 2011 BSD