Updated: 2022/Sep/29

Please read Privacy Policy. It's for your privacy.

CTOD(9)                    Kernel Developer's Manual                   CTOD(9)

NAME
     ctod - 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 ALSO
     param(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.

NetBSD 10.99                     April 8, 2011                    NetBSD 10.99