7.5.5.2 Common Option Attributes

These option attributes are optional. Any that do appear in the definition of a flag, may appear only once.

`value'

The flag character to specify for traditional option flags, e.g., -L.

`max'

Maximum occurrence count (invalid if disable present). The default maximum is 1. NOLIMIT can be used for the value, otherwise it must be a number or a #define that evaluates to a number.

`min'

Minimum occurrence count. If present, then the option must appear on the command line. Do not define it with the value zero (0).

`must-set'

If an option must be specified, but it need not be specified on the command line, then specify this attribute for the option.

`enable'

Long-name prefix for enabling the option (invalid if disable not present). Only useful if long option names are being processed.

`disable'

Prefix for disabling (inverting sense of) the option. Only useful if long option names are being processed.

`enabled'

If default is for option being enabled. (Otherwise, the OPTST_DISABLED bit is set at compile time.) Only useful if the option can be disabled.

`ifdef'

`ifndef'

If an option is relevant on certain platforms or when certain features are enabled or disabled, you can specify the compile time flag used to indicate when the option should be compiled in or out. For example, if you have a configurable feature, mumble that is indicated with the compile time define, WITH_MUMBLING, then add:

ifdef = WITH_MUMBLING;

Take care when using these. There are several caveats:

• The case and spelling must match whatever is specified.
• Do not confuse these attributes with the AutoGen directives of the same names, See section Controlling What Gets Processed. These cause C preprocessing directives to be inserted into the generated C text.
• Only one of these attributes may apply to any given option.
• The VALUE_OPT_ values are #define-d. If WITH_MUMBLING is not defined, then the associated VALUE_OPT_ value will not be #define-d either. So, if you have an option named, MUMBLING that is active only if WITH_MUMBLING is #define-d, then VALUE_OPT_MUMBLING will be #define-d iff WITH_MUMBLING is #define-d. Watch those switch statements.

This document was generated by Bruce Korb on September, 30 2006 using texi2html 1.76.