NAME
standards — UNIX standards behavior on HP-UX
DESCRIPTION
HP-UX conforms to various UNIX standards. In some cases, these
standards conflict. This manpage describes the methods that
programmers and users must follow to have an application conform
and execute according to a particular UNIX standard.
UNIX Standard Conformant Programmer Environment
The following table lists feature test macros and environment variables
that must be defined while compiling an application.
Both a feature test macro and an environment variable
must
be defined while compiling the application so that
the application conforms and executes according to a
particular UNIX standard.
Otherwise, the behavior is undefined.
Standard Feature Test Macros to be Environment variable
defined during compilation to be set
UNIX 95 _XOPEN_SOURCE_EXTENDED=1 UNIX95 or
UNIX_STD=95 or
UNIX_STD=1995
UNIX 2003 _XOPEN_SOURCE=600 UNIX_STD=2003
The compiler uses the feature test macros to obtain the appropriate
namespace from the header files.
The compiler uses the environment variable to link in an appropriate
object file to the executable.
Using the environment variable customizes libc to match UNIX standards
for various functions.
If an application has already been compiled for default HP-UX behavior
or for one particular standard, and needs to change to a particular UNIX
standard behavior, recompile the application as specified in the above table.
For an HP-UX command to conform to a particular UNIX standard behavior,
the application has to set the corresponding environment variable
as specified in the above table before executing that command.
UNIX Standard Conformant User Environment
To enable a particular UNIX standard conformant user environment,
set the corresponding environment variable as defined in the
above table.
EXAMPLES
The following examples shows an application example.
To have the system be conformant to UNIX2003 behavior,
set the
UNIX_STD
environment variable
to
2003
and define the
_XOPEN_SOURCE=600
feature test macro
before compilation.
$ export UNIX_STD=2003
$ c99 -D_XOPEN_SOURCE=600 foo.c
The following example changes the
ls
command to have UNIX95 behavior by
setting one of the environment variables to
UNIX95
or to
UNIX_STD=95
before executing that command.
There are three ways of setting the environment variable for UNIX95:
$ export UNIX95=1
$ ls options
or
$ export UNIX_STD=95
$ ls options
or
$ export UNIX_STD=1995
$ ls options
Printable version
