HP TACL User Manual

Writing an Exception Handler
Developing TACL Routines
3–22 107365 Tandem Computers Incorporated
When you invoke command_processor, the output looks like this:
16> command_processor
Enter cmd: add
ADD
Enter cmd: clr
Invalid command
TACL error occurred.
17> command_processor
Enter cmd: <BREAK>
BREAK key pressed.
18>
Use the routine in Figure 3-14, purgefiles, to purge files based on file name
templates. Purgefiles illustrates the use of #FILTER, #FILENAMES, and the
TEMPLATES alternative for the #ARGUMENT built-in function. To use this routine,
load the associated file and enter:
purgefiles [ ! ] file-template [ , file-template ] ...
The ! specifies purge without confirmation; without it, the routine prompts for each
file. If the routine encounters a _BREAK exception, it displays a message with the
number of files purged and the number not purged, and then exits.
Figure 3-14. Returning Information From a Release Handler (Page 1 of 3)
?SECTION purgefiles ROUTINE
[#CASE [#EXCEPTION]
|_CALL|
|_BREAK _ERROR|
#PUSH errtext
#ERRORTEXT /CAPTURE errtext/
#OUTPUT Break or error terminated function.
#OUTPUT
[#IF NOT [#EMPTYV /BLANK/ errtext] |THEN|
#OUTPUTV errtext
#OUTPUT
]
#OUTPUT Number of files purged = [filespurged]
#OUTPUT Number of files not purged = [filesnotpurged]
#UNFRAME
#RETURN
]
#FRAME
== Filter _BREAK and TACL errors
#FILTER _BREAK _ERROR
[#PUSH filetemplate exclude prevname purgeerr opt firsttime
filespurged filesnotpurged
]

HP TACL Specifications

General

Name	HP TACL
Purpose	Task automation, system management, and application control
Category	Software
Platform	HP NonStop
Type	Scripting language
Developer	Hewlett-Packard

Summary

Section 1 An Overview of TACL

Running the Examples in This Manual

Instructions for executing manual examples, including setting required variables.

About This Manual

Section 2 Developing TACL Programs

Processing Character Data

Covers tasks like constructing text strings, analyzing output, and manipulating characters.

Debugging TACL Programs

Introduces the TACL debugger for step-by-step execution and variable examination.

Section 3 Developing TACL Routines

Processing Arguments

Details how routines handle arguments using #ARGUMENT, including options and alternatives.

Writing an Exception Handler

Explains handling events like BREAK keys or TACL errors using exception handlers.

4 Accessing Files

#REQUESTER Operation

Describes the #REQUESTER function for opening files and initiating I/O operations.

Requesting Waited Reads

Explains opening files for waited read operations using #REQUESTER.

5 Initiating and Communicating With Processes

Initiating a Process: RUN and #NEWPROCESS

Covers starting processes using RUN and #NEWPROCESS, including startup options.

Using the INLINE Facility

Using INV and OUTV

Using $RECEIVE

Using #SERVER

6 Running TACL as a Server

Running a TACL Process as a Server

Explains making a TACL process a server by establishing its IN file as $RECEIVE.

Running TACL Code as a Server

Details providing TACL code for a TACL-server process using #INPUTV and #REPLYV.

Using TACL as a Pathway Server

Describes creating a Pathway environment with TCP and TACL servers to process requests.

7 Using Programmatic Interfaces

Overview of SPI and EMS

Using SPI

Using EMS

8 Example of a System Management Program

Monitoring System Operation