View Source: POSIXLY_CORRECT - Waikato Linux Users Group

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[POSIXLY_CORRECT] is an EnvironmentVariable 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. (See [Democracy Triumphs in Disk Units | http://groups.google.com/groups?selm=9108281809.AA03552%40mole.gnu.ai.mit.edu])

Many of the GNU tools comply with [POSIX] by default, except for where the author thinks the [POSIX] standard is wrong or dumb. <tt>:)</tt> For the same reason, some programs treat an variable named [POSIX_ME_HARDER] as an acceptable alias for [POSIXLY_CORRECT].

Some programs that behave differently if [POSIXLY_CORRECT] is set:

* bash(1)
* df(1)
* patch(1)
* true(1), false(1) and yes(1)

  From the NEWS file for true(1)/false(1):
  > false and true now ignore <tt>--help</tt> and <tt>--version</tt> when [POSIXLY_CORRECT] is set.

  yes(1) prints these options as output strings rather than ignoring them.

* any program using getopt(3), since the function stops processing options after the first non-option if [POSIXLY_CORRECT] is set

6 pages link to POSIXLY_CORRECT:

Last edited on Wednesday, March 30, 2005 12:13:26 pm by AristotlePagaltzis

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