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Table of Contents
- The HPFOPEN Intrinsic
- NOWAIT I/O
- NOWAIT I/O intrinsics
- Aborting NOWAIT I/O
- Limitations
- The FOPEN Intrinsic
- The BUILD Command
- The FILE Command
- Summary of Overrides
- Specifying a Record Format
- Fixed-length records
- Variable-length records
- Undefined-length records
- Specifying a File Type
- Standard files
- KSAM files
- RIO files
- Circular files
- Message files
- Specifying Record Size
- Specifying Disk Volume Restrictions
- Specifying a File Code
- Specifying Storage Format
When you create a file, you choose the attributes that file will have; your
choices are made on the basis of how the file will be used. A file's physical
characteristics are determined by the parameters you choose when you create the
file with the HPFOPEN/FOPEN intrinsic or the BUILD command,
or when you specify the file with the FILE command.
Once a file has been created, its physical characteristics
cannot be changed. The file can be renamed or purged, but the only
way to change its physical characteristics is by building a new
file and copying the contents of the old file into the new.
File equations and HPFOPEN/FOPEN calls cannot alter physical
characteristics of an existing file, but they can alter the way the file is to
be used. Other characteristics of the file that you create can be redefined
each time you open the file. Those characteristics are discussed in
later chapters in this manual.
In this chapter, we will address the following questions:
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