GETBSIZE(3)            FreeBSD Library Functions Manual            GETBSIZE(3)

NAME
     getbsize - get preferred block size

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <stdlib.h>

     char *
     getbsize(int *headerlenp, long *blocksizep);

DESCRIPTION
     The getbsize() function returns a preferred block size for reporting by
     system utilities df(1), du(1) and ls(1), based on the value of the
     BLOCKSIZE environment variable.  BLOCKSIZE may be specified directly in
     bytes, or in multiples of a kilobyte by specifying a number followed by
     ``K'' or ``k'', in multiples of a megabyte by specifying a number
     followed by ``M'' or ``m'' or in multiples of a gigabyte by specifying a
     number followed by ``G'' or ``g''.  Multiples must be integers.

     Valid values of BLOCKSIZE are 512 bytes to 1 gigabyte.  Sizes less than
     512 bytes are rounded up to 512 bytes, and sizes greater than 1 GB are
     rounded down to 1 GB.  In each case getbsize() produces a warning message
     via warnx(3).

     The getbsize() function returns a pointer to a null-terminated string
     describing the block size, something like "1K-blocks".  The memory
     referenced by headerlenp is filled in with the length of the string (not
     including the terminating null).  The memory referenced by blocksizep is
     filled in with block size, in bytes.

SEE ALSO
     df(1), du(1), ls(1), systat(1), environ(7)

HISTORY
     The getbsize() function first appeared in 4.4BSD.

FreeBSD 13.1-RELEASE-p6          June 11, 2017         FreeBSD 13.1-RELEASE-p6