HP 3000 Manuals HP 3000 Manuals
HPPIPE
Creates a pipe file type object defined as device type of streams, file
type of pipes, and record format of byte streams.
Syntax
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| I32 I32 I32 |
| HPPIPE(read_fd, write_fd, status)|
| |
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Parameters
read_fd 32-bit signed integer by reference (required)
Returns the read file descriptor for the pipe.
Attempts to write to a read file descriptor results
in an error.
write_fd 32-bit signed integer by reference (required)
Returns the write file descriptor for the pipe.
Attempts to read from a write file descriptor
results in an error.
status 32-bit signed integer by reference (optional)
Returns the status of the HPPIPE call. If no
errors or warnings are encountered, status returns
32-bits of zero. If errors or warnings are
encountered, status if interpreted as two 16-bit
fields:
bits (0:16): comprise status.info. A negative value indicates
an error condition, and a positive value indicates
a warning condition.
bits (16:16): comprise status.subsys. The value represents the
subsystem that sets the status information. The
subsystem identifier for HPPIPE is the file system
subsystem 143.
CAUTION If an error or warning is encountered and the status parameter
was not specified, HPPIPE causes the calling process to abort.
The following status.info values can be returned by HPPIPE:
Table 4-23.
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| Status Code Meaning |
| |
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| -461 Maximum open files for operating system exceeded. |
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| -18 Bounds violation on read_fd parameter. |
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| -18 Bounds violation on write_fd parameter. |
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| -80 An internal error occurred. |
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| -81 The operation failed due to a lack of system resources. |
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| -179 The user lacks the ability to create an object. |
| |
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Operation Notes
Enables creation of a pipe, which is a nameless object that can only be
reached from members of its process's family. Returns two file numbers
to the calling process that represent the write and read ends of the
pipe. Use the FWRITE and FREAD intrinsics to read and write to the pipe.
Data is returned in a first in, first out manner.
Related Information
Intrinsics FCLOSE, FCONTROL, FFILEINFO and FCHECK
Commands None
Manuals Resource Management Programmer's Guide
(32650-90024)