Guardian Procedure Calls Reference Manual (G06.25+)

Guardian Procedure Calls Reference Manual—522629-013
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Introduction to Guardian
Procedure Calls
System services are tasks such as retrieving a record from a disk, writing a file to a
tape, sending messages to other processes, or alerting your process to some kind of
system error that the operating system or a subsystem performs on behalf of a
program.
Your programs can make use of these services by calling appropriate Guardian
procedures. For example, using the Guardian READ procedure allows a program to
read data from a file.
To help you understand how to use the Guardian procedure-call descriptions in this
manual, this section describes:
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The different types of Guardian procedure calls
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Reference parameter overlap
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H-series and G-series Guardian procedures and superseded Guardian procedures
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External declaration files for Guardian procedures
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Parameter declaration files for Guardian procedures
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An example of a Guardian procedure call
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Calling Guardian procedures from a Transaction Application Language (TAL)
application
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Calling Guardian procedures from a C application
This manual describes most of the Guardian procedures and shows the syntax for
calling these procedures from a TAL or C program.