Ahelp for CIAO 3.4

To learn how to use the help system for CIAO (ahelp), say:

unix% ahelp

Ahelp can be used from the command line and from within ChIPS and Sherpa. The help documents are accessed by subject (a single word, case insensitive), so to get help on the tool dmextract try

unix% ahelp dmextract

and to search on a word use about (it is an alias to ahelp -k) which will bring up a list of all matching documents or - if there is only one match - display that document. Here we look for any document on "times":

unix% about times
--------------------------------------------------------------------------------
| SUBJECT | CONTEXT  |                        SYNOPSIS                         |
|---------|----------|---------------------------------------------------------|
| times   | chandra  | "Times" used in Chandra datasets and Chandra data       |
|         |          | analysis                                                |
|---------|----------|---------------------------------------------------------|
| times   | slangrtl | Get process times                                       |
--------------------------------------------------------------------------------

Use "ahelp subject" ("ahelp context subject" for non-unique cases) e.g.:
 ahelp times
 ahelp slangrtl times

In general you will be now be able to say "ahelp <subject>" to read the help for that document. However, there are a number of cases - such as shown above - when the same subject matches different contexts. For such cases you have to say "ahelp <context> <subject>" (note the order) as described at the end of the list of matches. To find out the information on Times as used in Chandra datasets and analysis you would therefore say

unix% ahelp chandra times

Read the ahelp document for more information on the ahelp system, such as:

• accessing the on-line versions of the documents from the command-line
• reading parts of the document - e.g. only the examples or the parameter list