getbsize(3) [mojave man page]
GETBSIZE(3) BSD 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), ls(1) and systat(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. 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. BSD
November 16, 2012 BSD
Check Out this Related Man Page
DU(1) BSD General Commands Manual DU(1) NAME
du -- display disk usage statistics SYNOPSIS
du [-H | -L | -P] [-a | -d depth | -s] [-cghkmnrx] [file ...] DESCRIPTION
The du utility displays the file system block usage for each file argument and for each directory in the file hierarchy rooted in each direc- tory argument. If no file is specified, the block usage of the hierarchy rooted in the current directory is displayed. The options are as follows: -H Symbolic links on the command line are followed. (Symbolic links encountered in the tree traversal are not followed.) -L All symbolic links are followed. -P No symbolic links are followed. -a Display an entry for each file in the file hierarchy. -c Display the grand total after all the arguments have been processed. -d Display an entry files and directories depth directories deep. -g If the -g flag is specified, the number displayed is the number of gigabyte (1024*1024*1024 bytes) blocks. -h If the -h flag is specified, the numbers will be displayed in "human-readable" format. Use unit suffixes: B (Byte), K (Kilobyte), M (Megabyte), G (Gigabyte), T (Terabyte) and P (Petabyte). -k By default, du displays the number of blocks as returned by the stat(2) system call, i.e. 512-byte blocks. If the -k flag is speci- fied, the number displayed is the number of kilobyte (1024 bytes) blocks. Partial numbers of blocks are rounded up. -m If the -m flag is specified, the number displayed is the number of megabyte (1024*1024 bytes) blocks. -n Ignore files and directories with user "nodump" flag (UF_NODUMP) set. -r Generate warning messages about directories that cannot be read. This is the default behaviour. -s Display only the grand total for the specified files. -x Filesystem mount points are not traversed. du counts the storage used by symbolic links and not the files they reference unless the -H or -L option is specified. If either the -H or -L options are specified, storage used by any symbolic links which are followed is not counted or displayed. The -H, -L and -P options over- ride each other and the command's actions are determined by the last one specified. Files having multiple hard links are counted (and displayed) a single time per du execution. ENVIRONMENT
BLOCKSIZE If the environment variable BLOCKSIZE is set, and the -g, -h, -k, and -m options are not specified, the block counts will be dis- played in units of that size block. SEE ALSO
df(1), chflags(2), fts(3), getbsize(3), symlink(7), quot(8) HISTORY
A du command appeared in Version 6 AT&T UNIX. BSD
September 24, 2006 BSD