TACL Reference Manual

Built-In Functions and Variables
HP NonStop TACL Reference Manual—429513-018
9-111
#DELTA Built-In Function
#DELTA Built-In Function
#DELTA, the TACL character editor, allows you to perform complex operations on text.
Although it is mainly for editing text from within macros and routines, you can use
#DELTA interactively as well. Using #DELTA interactively allows you to observe how
#DELTA works and lets you debug existing #DELTA macros.
You can also use #DELTA to read text from a file, modify the text and write the
modified text to another file.
The #CHARxxx and #LINExxx string-handling functions perform text operations that
are similar to #DELTA capabilities. You might find that you can avoid using #DELTA
altogether, doing all the character processing you need-much more simply-through the
use of the #CHARxxx and #LINExxx string-handling functions.
variable-level
is a variable level whose type must be DELTA. #DELTA executes commands from
this variable level.
text
is a text string that is inserted into the #DELTA buffer before #DELTA starts.
Result
#DELTA returns whatever is left in the #DELTA buffer after editing.
Considerations
•
If you include the COMMANDS option, #DELTA executes the commands in
variable-level and exits.
•
If you omit the COMMANDS option, #DELTA accepts commands interactively from
the terminal until it receives two consecutive CTRL-y characters.
A detailed description of #DELTA operations and commands follows.
Most of the examples that will be given are interactive (the COMMANDS option, which
allows you to name a variable level containing a set of #DELTA commands, is not used
in this discussion). Using #DELTA interactively allows you to observe how #DELTA
operates, to work on individual parts of #DELTA command variables before formally
defining them as a whole, and to debug existing #DELTA macros.
The #DELTA prompt appears in the form #DELTA n> ; the prompt is displayed only
when you use #DELTA interactively. At the #DELTA prompt, you can enter #DELTA
commands.
#DELTA [ / COMMANDS variable-level / ] [ text ]