int64(3)

NAME
     int64, add64, add64u, add64ul, sub64,  sub64u,  sub64ul,  diff64,  cvu64,
     cvul64,  cv64u,  cv64ul,  div64u, rem64u, mul64u, cmp64, cmp64u, cmp64ul,
     ex64lo, ex64hi, make64 - 64 bit disk offset computations

SYNOPSIS
     #include <minix/partition.h>

     u64_t add64(u64_t i, u64_t j)
     u64_t add64u(u64_t i, unsigned j)
     u64_t add64ul(u64_t i, unsigned long j)
     u64_t sub64(u64_t i, u64_t j)
     u64_t sub64u(u64_t i, unsigned j)
     u64_t sub64ul(u64_t i, unsigned long j)
     unsigned diff64(u64_t i, u64_t j)
     u64_t cvu64(unsigned i)
     u64_t cvul64(unsigned long i)
     unsigned cv64u(u64_t i)
     unsigned long cv64ul(u64_t i)
     unsigned long div64u(u64_t i, unsigned j)
     unsigned rem64u(u64_t i, unsigned j)
     u64_t mul64u(unsigned long i, unsigned j)
     int cmp64(u64_t i, u64_t j)
     int cmp64u(u64_t i, unsigned j)
     int cmp64ul(u64_t i, unsigned long j)
     unsigned long ex64lo(u64_t i)
     unsigned long ex64hi(u64_t i)
     u64_t make64(unsigned long lo, unsigned long hi)

DESCRIPTION
     The int64 family of functions allow Minix to handle  disks  of  up  to  4
     terabytes  using  32  bit  sector  numbers  and  64 bit byte offsets on a
     machine where the C  type  long  is  32  bits.   The  <minix/partition.h>
     include file defines a 64 bit data type, u64_t, and a number of functions
     to operate on them.  Note that these functions are geared towards  common
     disk  offset  and block computations, and do not provide a full set of 64
     bit operations.  They are:

     u64_t add64(u64_t i, u64_t j)
          Add the 64 bit numbers i and j forming a 64 bit result.

     u64_t add64u(u64_t i, unsigned j)
          Add an unsigned j to a 64 bit number i forming a 64 bit result.

     u64_t add64ul(u64_t i, unsigned long j)
          Add an unsigned long j to a 64 bit number i forming a 64 bit result.

     u64_t sub64(u64_t i, u64_t j)
          Subtract the 64 bit number j from the 64 bit number i forming  a  64
          bit result.

     u64_t sub64u(u64_t i, unsigned j)
          Subtract the unsigned j from the 64 bit number i forming  a  64  bit
          result.

     u64_t sub64ul(u64_t i, unsigned long j)
          Subtract the unsigned long j from the 64 bit number i forming  a  64
          bit result.

     unsigned diff64(u64_t i, u64_t j)
          Subtract the 64 bit number j from the 64 bit  number  i  forming  an
          unsigned.  Overflow is not checked.

     u64_t cvu64(unsigned i)
          Convert an unsigned to a 64 bit number.

     u64_t cvul64(unsigned long i)
          Convert an unsigned long to a 64 bit number.

     unsigned cv64u(u64_t i)
          Convert a 64 bit number to an unsigned if it fits, otherwise  return
          UINT_MAX.

     unsigned long cv64ul(u64_t i)
          Convert a 64 bit number to an unsigned long if  it  fits,  otherwise
          return ULONG_MAX.

     unsigned long div64u(u64_t i, unsigned j)
          Divide the 64 bit number i by the  unsigned  j  giving  an  unsigned
          long.   Overflow  is  not  checked.   (Typical "byte offset to block
          number" conversion.)

     unsigned rem64u(u64_t i, unsigned j)
          Compute the remainder of the division of the 64 bit number i by  the
          unsigned  j  as  an unsigned.  (Typical "byte offset within a block"
          computation.)

     u64_t mul64u(unsigned long i, unsigned j)
          Multiply the unsigned long i by the  unsigned  j  giving  a  64  bit
          number.  (Typical "block number to byte offset" conversion.)

     int cmp64(u64_t i, u64_t j)
          Compare two 64 bit numbers.  Returns -1 if i < j, 0 if i == j, and 1
          if i > j.

     int cmp64u(u64_t i, unsigned j)
          Likewise compare a 64 bit number with an unsigned.

     int cmp64ul(u64_t i, unsigned long j)
          Likewise compare a 64 bit number with an unsigned long.

     unsigned long ex64lo(u64_t i)
          Extract the low 32 bits of a 64 bit number.

     unsigned long ex64hi(u64_t i)
          Extract the high 32 bits of a 64 bit number.

     u64_t make64(unsigned long lo, unsigned long hi)
          Combine the low and high parts of a  64  bit  number  to  a  64  bit
          number.   (The  last three functions are used to pass 64 bit numbers
          in messages within the kernel.  They should not be used for anything
          else.)

SEE ALSO
     fcntl(2).

NOTES
     The lseek system call is still limited to a 32 bit offset.  Use

          fcntl(fd, F_SEEK, u64_t offset)

     to seek to a 64 bit position.  This only makes sense on a disk device.

AUTHOR
     Kees J. Bot (kjb@cs.vu.nl)