#include <GetLongOpt.h> GetLongOpt::GetLongOpt(const char optmark = '-'); int GetLongOpt::parse(int argc, char * const *argv); int GetLongOpt::parse(char * const str, char * const p); int GetLongOpt::enroll(const char * const opt, const OptType t, const char * const desc, const char * const val); const char * GetLongOpt::retrieve(const char * const opt) const; void GetLongOpt::usage(ostream &outfile = cout) const; void GetLongOpt::usage(const char *str);
The constructor for GetLongOpt takes an optional argument: the option marker. If unspecified, this defaults to '-', the standard (?) Unix option marker. For example, a DOS addict may want to specify '/' for the option marker!
GetLongOpt::enroll adds option specifications to its internal database. The first argument is the option sting. The second is an enum saying if the option is a flag (GetLongOpt::NoValue), if it requires a mandatory value (GetLongOpt::MandatoryValue) or if it takes an optional value (GetLongOpt::OptionalValue). The third argument is a string giving a brief description of the option. This description will be used by GetLongOpt::usage. GetLongOpt, for usage-printing, uses $val to represent values needed by the options. <$val> is a mandatory value and [$val] is an optional value. The final argument to GetLongOpt::enroll is the default string to be returned if the option is not specified. For flags (options with NoValue), use "" (empty string, or in fact any arbitrary string) for specifying TRUE and 0 (null pointer) to specify FALSE.
GetLongOpt::usage is overloaded. If passed a string s, it sets the internal usage string to s. Otherwise it simply prints the command usage. The options and their descriptions (as specified during enroll) are printed in the order they are enrolled.
GetLongOpt::parse is also overloaded. It can either parse a string of options (typically given from the environment), or it can parse the command line args (argc, argv). In either case a return value < 1 represents a parse error. Appropriate error messages are printed when errors are seen. GetLongOpt::parse, in its first form, takes two strings: the first one is the string to be parsed and the second one is a string to be prefixed to the parse errors. In its second form, GetLongOpt::parse takes in argc and argv and returns the the optind (see getopt(3)) if parsing is successful. Successful parsing, in either form of GetLongOpt::parse, updates the values of the options within the internal database.
The values of the options that are enrolled in the database can be retrieved using GetLongOpt::retrieve. This returns a string and this string should be converted to whatever type you want. See atoi(3), atof(3), atol(3) etc. I suppose you would do a GetLongOpt::parse before retrieving. Otherwise all you would get are the default values you gave while enrolling! Ambiguities while retrieving (may happen when options are abbreviated) are resolved by taking the matching option that was enrolled last.
If you try to retrieve something you did not enroll, you will get a warning message. This means that you probably had made a typo somewhere while enrolling or retrieving.
S Manoharan Advanced Computer Research Institute 1 Boulevard Marius Vivier-Merle 69443 Lyon Cedex 03 France mano@acri.fr