woption Struct Reference

Describe the long-named options requested by the application. More...

#include <wgetopt.h>

Data Fields
wchar_t *	name
	long name for switch
int	has_arg
	Must be one of no_argument, required_argument and optional_argument.
int *	flag
	If non-null, the flag whose value should be set if this switch is encountered.
int	val
	If flag is non-null, this is the value that flag will be set to.

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Detailed Description

Describe the long-named options requested by the application.

The LONG_OPTIONS argument to getopt_long or getopt_long_only is a vector of `struct option' terminated by an element containing a name which is zero.

The field `has_arg' is: no_argument (or 0) if the option does not take an argument, required_argument (or 1) if the option requires an argument, optional_argument (or 2) if the option takes an optional argument.

If the field `flag' is not NULL, it points to a variable that is set to the value given in the field `val' when the option is found, but left unchanged if the option is not found.

To have a long-named option do something other than set an `int' to a compiled-in constant, such as set a value from `optarg', set the option's `flag' field to zero and its `val' field to a nonzero value (the equivalent single-letter option character, if there is one). For long options that have a zero `flag' field, `getopt' returns the contents of the `val' field.

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Field Documentation

int woption::has_arg

Must be one of no_argument, required_argument and optional_argument. has_arg can't be an enum because some compilers complain about type mismatches in all the code that assumes it is an int.

int woption::val

If flag is non-null, this is the value that flag will be set to. Otherwise, this is the return-value of the function call.

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The documentation for this struct was generated from the following file:

• wgetopt.h

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