G::GetOpt Class Reference

A command line option parser. More...

#include <ggetopt.h>

Public Types
typedef std::string::size_type	size_type

Public Member Functions
	GetOpt (const Arg &arg, const std::string &spec)
	Constructor taking a Arg reference and a G::Options specification string. More...
	GetOpt (const StringArray &arg, const std::string &spec)
	An overload taking a vector of command-line arguments. More...
void	reload (const StringArray &arg)
	Reinitialises the object with the given command-line arguments. More...
void	addOptionsFromFile (size_type n=1U)
	Adds options from the config file named by the n'th non-option command-line argument (zero-based but allowing for the program name in argv0). More...
void	addOptionsFromFile (const Path &file)
	Adds options from the given config file. More...
const Options &	options () const
	Returns a reference to the internal option specification object.
Arg	args () const
	Returns all the non-option command-line arguments.
StringArray	errorList () const
	Returns the list of errors.
bool	hasErrors () const
	Returns true if there are errors.
void	showErrors (std::ostream &stream, std::string prefix_1, std::string prefix_2=std::string(": ")) const
	A convenience function which streams out each errorList() item to the given stream, prefixed with the given prefix(es). More...
void	showErrors (std::ostream &stream) const
	An overload which has a sensible prefix.
bool	contains (char option_letter) const
	Returns true if the command line contains the option identified by its short-form letter. More...
bool	contains (const std::string &option_name) const
	Returns true if the command line contains the option identified by its long-form name. More...
unsigned int	count (const std::string &option_name) const
	Returns the number of times the option was supplied.
std::string	value (const std::string &option_name, const std::string &default_=std::string()) const
	Returns the value related to the option identified by its long-form name. More...
std::string	value (char option_letter, const std::string &default_=std::string()) const
	Returns the value related to the option identified by its short-form letter. More...

Detailed Description

A command line option parser.

Usage:

G::Arg arg( argc , argv ) ;
G::GetOpt opt( arg , "e!extra!does something! extra!1!something!1" "|" "h!help!shows help!!0!!1" ) ;
if( opt.hasErrors() ) { opt.showErrors( std::cerr ) ; exit( 2 ) ; }
if( opt.contains("help") ) { opt.options().showUsage( std::cout , arg.prefix() , " [<more>]" ) ; exit( 0 ) ; }
run( opt.args() , opt.contains("extra") ? opt.value("extra") : std::string() ) ;

See Also

G::Arg

Definition at line 55 of file ggetopt.h.

Constructor & Destructor Documentation

G::GetOpt::GetOpt	(	const Arg &	arg,
		const std::string &	spec
	)

Constructor taking a Arg reference and a G::Options specification string.

Parsing errors are reported via errorList().

Definition at line 33 of file ggetopt.cpp.

G::GetOpt::GetOpt	(	const StringArray &	arg,
		const std::string &	spec
	)

An overload taking a vector of command-line arguments.

The program name in the first argument is expected but ignored.

Definition at line 41 of file ggetopt.cpp.

Member Function Documentation

void G::GetOpt::addOptionsFromFile

(

size_type

n = 1U

)

Adds options from the config file named by the n'th non-option command-line argument (zero-based but allowing for the program name in argv0).

The n'th argument is then removed. Does nothing if the n'th argument does not exists or if it is empty. Throws if the file is specified but cannot be opened. Parsing errors are added to errorList().

void G::GetOpt::addOptionsFromFile

(

const Path &

file

)

Adds options from the given config file.

Throws if the file cannot be opened. Parsing errors are added to errorList().

Definition at line 98 of file ggetopt.cpp.

bool G::GetOpt::contains

(

char

option_letter

)

const

Returns true if the command line contains the option identified by its short-form letter.

Definition at line 113 of file ggetopt.cpp.

bool G::GetOpt::contains

(

const std::string &

option_name

)

const

Returns true if the command line contains the option identified by its long-form name.

Definition at line 118 of file ggetopt.cpp.

void G::GetOpt::reload

(

const StringArray &

arg

)

Reinitialises the object with the given command-line arguments.

The program name in the first position is expected but ignored.

Definition at line 49 of file ggetopt.cpp.

void G::GetOpt::showErrors	(	std::ostream &	stream,
		std::string	prefix_1,
		std::string	prefix_2 = std::string(": ")
	)		const

A convenience function which streams out each errorList() item to the given stream, prefixed with the given prefix(es).

The two prefixes are simply concatenated.

Definition at line 154 of file ggetopt.cpp.

std::string G::GetOpt::value	(	const std::string &	option_name,
		const std::string &	default_ = std::string()
	)		const

Returns the value related to the option identified by its long-form name.

Returns a string that is a comma-separated list if multi-valued.

Definition at line 134 of file ggetopt.cpp.

std::string G::GetOpt::value	(	char	option_letter,
		const std::string &	default_ = std::string()
	)		const

Returns the value related to the option identified by its short-form letter.

Returns a string that is a comma-separated list if multi-valued. Precondition: contains(option_letter)

Definition at line 128 of file ggetopt.cpp.

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The documentation for this class was generated from the following files:

• /home/graeme/videotools/src/glib/ggetopt.h
• /home/graeme/videotools/src/glib/ggetopt.cpp