---
name: "getbsize"
section: "3"
platform: "linux"
package: "libbsd-dev"
version: "0.8.3-1"
release: "Debian 9 (Stretch)"
platforms: ["linux", "freebsd", "macos"]
url: "https://new.carta.tech/getbsize"
---

# getbsize(3)

get preferred block size

## NAME

**getbsize** – get preferred block size

## LIBRARY

library “libbsd”

## SYNOPSIS

**#include \<bsd/stdlib.h\>**

*char* *\**\

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

## DESCRIPTION

The **getbsize**() function returns a preferred block size for reporting by system utilities [df(1)](/df/1.md), [du(1)](/du/1.md), [ls(1)](/ls/1.md) and [systat(1)](/systat/1.md), 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)](/df/1.md), [du(1)](/du/1.md), [ls(1)](/ls/1.md), [systat(1)](/systat/1.md), [environ(7)](/environ/7.md)

## HISTORY

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