Penguin
Note: You are viewing an old revision of this page. View the current version.

POSIXLY_CORRECT is an environment variable that some programs use to follow strict POSIX standards behaviour, where that isn't the default.

Probably the most well-known example of this is that POSIX states that filesystem blocks are 512 bytes per block, so the GNU fileutils such as df(1) and GNU tar(1) use 512 if the variable POSIXLY_CORRECT is set, and 1024 bytes per block by default.

Many of the GNU tools comply with POSIX by default, except for where the author thinks the POSIX standard is wrong or dumb. :) As a result, some programs also check if a variable named POSIX_ME_HARDER is set as an acceptable alias for POSIXLY_CORRECT. See http://groups.google.com/groups?selm=9108281809.AA03552%40mole.gnu.ai.mit.edu

Some programs that behave differently if POSIXLY_CORRECT is set: