standards(5) File Formats Manual standards(5)
standards - UNIX standards behavior on HP-UX
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 fea-
ture 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 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.
The following examples shows an application example. To have the system be conformant to UNIX2003 behavior, set the environment variable
to and define the feature test macro before compilation.
The following example changes the command to have UNIX95 behavior by setting one of the environment variables to or to before executing
that command. There are three ways of setting the environment variable for UNIX95: