Technical data

SunOS 5.5 Ioctl Requests streamio(7I)
Processes that wish to receive SIGPOLL signals must explicitly register
to receive them using I_SETSIG. If several processes register to receive
this signal for the same event on the same stream, each process will be
signaled when the event occurs.
If the value of arg is zero, the calling process will be unregistered and
will not receive furtherSIGPOLL signals. On failure, errno is set to one
of the following values:
EINVAL arg value is invalid or arg is zero and process is not
registered to receive theSIGPOLL signal.
EAGAIN Allocation of a data structure to store the signal request
failed.
I_GETSIG Returns the events for which the calling process is currently registered
to be sent aSIGPOLL signal. The events are returned as a bitmask
pointed to by arg, where the events are those specified in the description
of I_SETSIG above. On failure, errno is set to one of the following
values:
EINVAL Process not registered to receive theSIGPOLL signal.
EFAULT arg points outside the allocated address space.
I_FIND Compares the names of all modules currently present in the stream to
the name pointed to by arg, and returns 1 if the named module is
present in the stream. It returns 0 if the named module is not present.
On failure, errno is set to one of the following values:
EFAULT arg points outside the allocated address space.
EINVAL arg does not contain a valid module name.
I_PEEK Allows a user to retrieve the information in the first message on the
stream head read queue without takingthe message off the queue.
I_PEEK is analogous to getmsg(2) except that it does not remove the
message from the queue. arg points to a strpeek structure, which con-
tains the following members:
struct strbuf ctlbuf;
struct strbuf databuf;
long flags;
The maxlen field in the ctlbuf and databuf strbuf structures (see
getmsg(2)) must be set to the number of bytes of control information
and/or data information, respectively, to retrieve. flags may be set to
RS_HIPRI or 0.IfRS_HIPRI is set, I_PEEK will look for a high priority
message on the stream head read queue. Otherwise, I_PEEK will look for
the first message on the stream head read queue.
modified 24 Jan 1995 7I-329