Guardian Procedure Calls Reference Manual

1 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:
• The different types of Guardian procedure calls
• Reference parameter overlap
• G-series, H-series, and J-series Guardian procedures and superseded Guardian procedures
• SPR requirements for increased Enscribe Limits for the H06.28/J06.17 release
• Header files for Guardian procedures
• Parameter declaration files for Guardian procedures
• An example of a Guardian procedure call
• Calling Guardian procedures from a Transaction Application Language (TAL) application
• 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.
You can also call Guardian procedures from programs written in FORTRAN, BASIC, COBOL, or
C++. How a Guardian procedure is called depends on the programming language. Some
languages provide extensions for calling Guardian procedures. Some languages (other than TAL)
allow your code to contain TAL code that calls Guardian procedures using TAL syntax. For
information on calling the Guardian procedures described in this manual from other languages,
see the appropriate manual:
See:For information on translating calls in
this manual to:
FORTRAN Reference ManualFORTRAN
EXTENDED BASIC Programmer's GuideBASIC
COBOL85 for NonStop Systems ManualCOBOL Manual for TNS/E
Programs
COBOL
C/C++ Programmer's GuideC
C/C++ Programmer's GuideC++
For applications written in programming languages other than TAL, be cautious about using TAL
to call Guardian procedures. This method of invoking the services provided by Guardian procedures
can interfere with the run-time environment established for the programming language. If possible,
use an extension of your programming language instead of embedded TAL code to invoke a
Guardian service (such as reading from or writing to a file).
Types of Guardian Procedure Calls
Table 2 shows the types of Guardian procedures that are described in this manual. It also shows
the manuals where you can find programming information about these procedures. For a list of
additional Guardian procedures that are documented in other manuals and the manuals in which
they are described, see Appendix H: Other Documented Guardian Procedures.
Types of Guardian Procedure Calls 29