STREAMS/UX for the HP 9000 Reference Manual

Differences Between STREAMS/UX and System V Release 4 STREAMS

HP-UX Changes to STREAMS/UX System Calls

There are HP-UX modiﬁcations to the fattach, ioctl, pipe, poll, putmsg,

putpmsg, select, signal, write, and writev system calls. These modiﬁcations

are as follows.

fattach Modifications

STREAMS/UX supports the fattach(3) and fdetach(3) library calls and the

fdetach(1m) command as described in the UNIX SVR4.2 Operating System

API Reference and the SVR4.2 Command Reference. In order to use fattach

and fdetach, the kernel must have the ffs ﬁle system conﬁgured. ffs is added

to the /stand/system ﬁle when STREAMS/UX is installed using swinstall. If

ffs has been deleted after the install was done, re-include it as follows,

regenerate a kernel, and reboot the system.

ffs

ioctl Modifications

STREAMS/UX supports ioctl as described in the SVR4.2 STREAMS

manual.

Also, note that the multiplexor ID number returned by I_LINK and

I_PLINK is a memory address, not a small integer such as 0, 1, 2, 3.

pipe Modifications

STREAMS/UX supports STREAMS-based pipes as an optional feature.

STREAMS/UX's STREAMS-based pipes behave as described in the UNIX

SVR4.2 Operating System API Reference and the UNIX System V Release 4

Programmer's Guide: STREAMS.

By default, pipes created by the pipe(2) system call are not

STREAMS-based. In order to get STREAMS-based pipes, the

/stand/system ﬁle must have the pipemod and pipedev module and driver

conﬁgured, and the tunable parameter streampipes must be set to 1 (one).

When STREAMS/UX is installed, the /stand/system ﬁle is modiﬁed to

include pipemod and pipedev, but streampipes is set to zero by default. The

kernel must be regenerated and the system rebooted if the setting of

streampipes to non-zero is to take effect. In other words, adb'ing the running

system to turn streampipes on will have no effect on the type of pipes

created by pipe(2). Once the kernel is regenerated and rebooted, all pipe(2)