[Chapter 4] 4.5 Using Online Help

4.5 Using Online Help

PL/Vision takes advantage of its own PLVhlp package to provide online help for its programs. As I've mentioned before, the help text that serves as source for this information resides in a set of parallel help packages. You can use several PL/SQL procedures or SQL*Plus scripts to access the help text.

To view the top-level help for a PL/Vision package, call the help.sql script (installed in the use subdirectory) as follows:

SQL> @help PKG (or SQL> exec PKG.help)

where PKG is the name of the package. So to see top-level help for PLVio, enter:

SQL> @help plvio (or SQL> exec plvio.help)

The case of your package name is not important. You will then see an overview of the package, a list of other topics available for this package and an index of programs defined in the package.

If the text exceeds the length of a PLVhlp page (the default is set to 25 lines), you will see this line after the end of the help text:

...more...

If there is more help text, you can then enter this command to see the next page:

SQL> @more (or SQL> exec plvhlp.more)

The format of the help index (also known as the help listing) is as follows:

N - program1_name         M - program2_name

where N is a number and program_name is the name of the program. You can use the number or the program name to get more information about that particular program or topic, as explained in the next section.

4.5.1 Zooming in on help text

You have two ways to zoom in on a particular topic within the current package's help text (the current package or program is defined by the parameter you pass in the call to help.sql ): the zoom.sql and zoomn.sql script s (both in the PL/Vision use subdirectory).

To zoom in on a topic by name you must first have executed the help.sql script (or the help procedure for the package of interest) to set the current program. Then you execute the zoom script, specifying the topic for which you want information:

SQL> @zoom put_line

If you do not want to have to type a program name or topic, you can also zoom in by a number from the help index. Again, you must first have executed the help.sql script to set the current program. Then you execute the zoom script, providing the topic number for which you want information. Suppose that my help index looks like this:

Listing for PACKAGE PLVio
1 - put_line        2 - get_line
3 - setsrc          4 - settrg

You can see information about the setsrc (set source) procedure by entering the following command at the SQL*Plus prompt:

SQL> @zoomn 3

NOTE: Many of these scripts will execute only within the SQL*Plus environment. Others are more generic SQL or PL/SQL utilities and can be used in any environment that executes SQL statements and PL/SQL anonymous blocks.