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The main components of the Starlink HLP system are as follows:
- A utility program CREHLP,
which reads a file of help text and writes a help library;
- A command procedure, HLIB, which front-ends the
CREHLP program.
- An object library containing, among other things:
- a subprogram, HLP_HELP, which executes an interactive
help session; and
- a subprogram, HLP_ERRMES, which translates internal error
codes into message strings.
For VAX/VMS and some Unix platforms two shareable libraries are supplied
in addition to the non-shared library. One
(HLP_IMAGE_ADAM.EXE on VMS) is for use with applications which run
under the ADAM software environment; the other
(HLP_IMAGE.EXE on VMS) is for use with stand-alone applications.
There are associated link option files (HLP_LINK.OPT and HLP_LINK_ADAM.OPT
for VMS, hlp_link and hlp_link_adam for Unix).
Other useful items include:
- An example application program, TSTHLP, which allows a help
library to be interrogated.
- An example help library, demo.hlp (source)
and demo.shl (library format).
- Example implementations of the user-supplied routines which
(a) output a line of text, (b) obtain an interactive response and
(c) translate a library name into a filename. The
names of these examples are HLP_OUTSUB, HLP_INSUB and
HLP_NAMETR respectively.
- The HLP_CREH subprogram, which carries out the translation of
a file of help text into the library format. (The CREHLP program
is just a front-end for HLP_CREH.)
Also supplied, but of less interest, are:
- A number of internal subprograms, some of which may have uses outside
the HLP system but are not officially part of the published interface
to the system,
e.g. some of the
character-string handling and I/O routines.
- Command procedures for managing development of the software.
- A utility program, LSTHLP, that lists a help library
file for diagnostic purposes, showing the various index pointers etc.
Section 5.3 includes an example of such a listing.

Next: USING HELP
Up: INTRODUCTION
Previous: Portability
HLP --- Interactive Help System
Starlink User Note 124
P. T. Wallace
13th June 1995
E-mail:ptw@star.rl.ac.uk