2.1.2 System Keywords

As just mentioned before, there are a fixed set of keywords to every NEMO program which are the ``hidden'' system keywords; their values are defined automatically for the user by the user-interface routines from environment variables or, when absent, sensible preset defaults. They handle certain global (system) features and are not listed through the 'help=' keyword. Of course their values can always be overridden by supplying it as a system parameter on the command line. In summary, the system keywords are:

• The help= keyword itself, gives you a list of all available keywords to this specific program but can also aid you in command completion and/or explanation of keywords.

• The debug= keyword lets you upgrade the debug output level. This may be useful to check proper execution when a program seemingly takes too long to complete, or to trace weird errors. Output is to stderr though. Default level is 0.

• The yapp= keyword lets you (re)define the graphics output device. Usually no default.

• The error= keyword allows you to override a specified number of fatal error calls. Not adviced really, but it's there to use in case you really know what you're doing^2.5 Default is 0.

• The review= keyword jumps the user into the REVIEW section before the actual execution of the NEMO program for a last review of the parameters before execution starts. (see also next section).

For a more detailed description of the system keywords and all their options see Appendix . The actual degree of implementation of the system keywords can be site dependent. Use the help=
? argument to any NEMO program to glean into the options the user interface was compiled with. Recent updates can also be found in NEMO's online manual pages, getparam(3NEMO).