2.1 Notation conventions
The following notation conventions are adopted in these help files (we hope that
they show up adequately using your WWW browser ... these have been tested
conservatively using NCSA XMosaic, exclude graphics whenever possible, and trying to use HTML as a true markup language).
Program syntax notation
All program run strings are indicated as standalone lines in what should appear as a large typewriter font like
this font
The same reference to program names and arguments imbedded in other text appears as
this text.
In particular any item which is not hilighted otherwise (like the program name, but also some
arguments) must be typed exactly as it is written (also respecting lower and upper case if
indicated). Note however that in most cases XAS is case-insensitive and the first letter(s)
of a word are indicated in upper case to indicate the shortest abbreviation allowed (i.e.
the compulsory part is in upper case and the optional one in lower case).
Program arguments which are to be typed exactly as they are written, but which have some
associated explanation, have an hypertext link associated to their first letter only, like
this example
Program arguments which have to be replaced by a value are indicated as a complete hypertext
link, pointing to more help, like in
this example
However if there is no associate hypertext link, but the argument shall be replaced by
some (self explanatory) value, it is indicated emphasized like in
this example
(The same emphasization is used sometimes to indicate prompts issued by a
program (or other output))
In addition, while usually all program arguments are optional, sometimes the first ones are
compulsory. A single square bracket indicates where the optional arguments begin (of course
this has NOT to be typed !!), like in this example :
command comp_arg1 comp_arg2 [ opt_arg1 opt_arg2
Moreover, while usually program arguments are strictly positional and must appear in the order
indicated (with placeholders replacing defaulted ones), in some cases the order of the arguments
depends on presence of previous arguments. In such cases the run string may be presented more than
once for the different cases, or the arguments which is present only conditionally is shown surrounded by
braces (which have not to be typed) like in
command comp_arg1 comp_arg2 [ opt_arg1 {opt_arg2} opt_arg2_or_3
Program dialogue examples
It is PLANNED to include some examples either in text or as screen dumps.
Each topic is arranged hierarchically in a set of pages, each one of which is kept
as short as possible, ideally a single screenful. These pages will provide usual
hypertext links, allowing free navigation and jumping from topic to topic.
However to aid a sequential navigation through the hierarchy at the bottom of each page there
is a set of four "text" buttons appearing like the following :
[Previous][Next][Up][Down]
These buttons have been removed from the PostScript hardcopy version of this manual.
Some of them will be hilighted (like the "Down" one in the example above) and clicking
on them will lead you respectively to :
- Previous : to the previous help page at the same level, if one exist,
otherwise up one level
- Next : to the next help page at the same level, if one exist,
otherwise to the next page one level up
- Up : to the page you came from one level up
- Down : to the next page at the level below the one you are in
Of course your browser may hilight with a different colour those which you have
already navigated. Try the "Down" button and come back here.
Buttons which appear unhilighted correspond to inactive choices
sax.iasf-milano.inaf.it/Xashelp/xasprog.1.html
:: original creation 2002 Sep 04 17:39:51 CEST ::
last edit 2002 Sep 04 17:39:51 CEST