non-critical impact:

pipe - different method for creating STREAMS-based pipes (NcWn222)

Problem description

By default, the Tru64 and HP-UX pipe function creates unidirectional pipes.

On Tru64 UNIX, pipe creates bidirectional, STREAMS-based pipes when the application is built in the System V Habitat or with _XOPEN_SOURCE_EXTENDED defined or _XOPEN_SOURCE defined to be 420 or higher. To use bidirectional STREAMS-based pipes on HP-UX, the kernel must be rebuilt with the tunable parameter streampipes set to a non-zero value.

There is an important difference between the Tru64 UNIX and HP-UX approaches. On Tru64 UNIX, if one application wants to use bidirectional STREAMS-based pipes, other applications can still use unidirectional pipes. On HP-UX, however, the streampipes setting is systemwide and affects all applications.

Identifiers

pipe

See also

• Background information on Input/Output (files, devices) impacts
• Background information on kernel impacts
• pipe(2)
• standards(5)

Solution description

To use bidirectional STREAMS-based pipes systemwide on HP-UX, rebuild the kernel with the streampipes tunable set to a non-zero value.

Review the applicable reference pages for more information.

See also

• pipe(2)
• streampipes(5)

Problem summary