Editing POSIX (section)

===512- vs 1024-byte blocks===
{{Primary sources|section|date=April 2025}}
POSIX mandates 512-byte default [[Block (computer memory)|block]] sizes for the [[Df (Unix)|df]] and [[Du (Unix)|du]] utilities, reflecting the typical size of blocks on disks. When [[Richard M. Stallman|Richard Stallman]] and the [[GNU]] team were implementing POSIX for the [[GNU operating system]], they objected to this on the grounds that most people think in terms of 1024 byte (or 1 [[Kibibyte|KiB]]) blocks. The environment variable {{tt|POSIX_ME_HARDER}} was introduced to allow the user to force the standards-compliant behaviour.<ref>{{Cite newsgroup|last=Stallman|first=Richard|title=Democracy Triumphs in Disk Units|date=28 August 1991|newsgroup=gnu.announce|message-id=9108281809.AA03552@mole.gnu.ai.mit.edu|via=Google Groups |url=http://groups.google.com/group/gnu.announce/msg/6c6e20b57ddb1a82?pli=1}}</ref> The variable name was later changed to {{tt|POSIXLY_CORRECT}}.<ref>{{cite web|publisher=GNU|url=https://www.gnu.org/prep/standards/standards.html#Non_002dGNU-Standards|title=GNU Coding Standards}}</ref> This variable is now also used for a number of other behaviour quirks.