TACL Reference Manual

The TACL Environment
HP NonStop TACL Reference Manual—429513-018
6-13
_EXECUTE Variables
_EXECUTE Variables
If you try to invoke a variable that is itself a directory, TACL searches that directory for
a variable named “_EXECUTE” and invokes that variable instead. The _EXECUTE
variable provides an automatic mechanism for special initialization activities such as:
•
Displaying a banner
•
Establishing a frame
•
Pushing the use list and altering it
•
Creating variables
•
Starting servers
•
Opening files
•
Establishing an exception handler
For example:
?SECTION _execute ROUTINE
PATHCOM $XXPM;RUN XX
Some application products allow you to enter TACL commands while you are using
them. This flexibility allows you to invoke another product without leaving the first
product.
Running a TACL Process in the Background
Another way to start a TACL process is to start one as a background process. A
background process is a process that runs with the NOWAIT, INV, or INLINE option. A
background process allows you to perform noninteractive tasks without interfering with
your interactive work. This type of TACL process starts running and can wait for
commands indefinitely; the background process does not prompt for input.
Initializing TACL and Specifying Input
To create a background TACL, specify a file name as the IN file. You can, for example,
specify an EDIT file with a set of TACL commands (and without a ?SECTION or
?TACL directive) as the IN file:
TACL /IN file-name, NOWAIT, NAME $TCL2/
To send commands interactively to the background process, use the INV or INLINE
run options. To execute a routine from the background process, you can supply an IN
file that loads and runs the routine.
When a background TACL starts, you do not need to log on to it; it automatically starts
up logged on as the user who started it.