casacore::Input Class Reference

More...

#include <Input.h>

Public Member Functions
	Input (Int createEnv=0)
	The default constructor enables the creation of parameters. More...
	~Input ()
	Destructor. More...
void	create (const String &key)
	Create a new parameter, either from scratch or looking it up from an internal list of templates. More...
void	create (const String &key, const String &value)
void	create (const String &key, const String &value, const String &help)
void	create (const String &key, const String &value, const String &help, const String &type)
void	create (const String &key, const String &value, const String &help, const String &type, const String &range)
void	create (const String &key, const String &value, const String &help, const String &type, const String &range, const String &unit)
void	close ()
	Disable the creation of parameters. More...
void	readArguments (int argc, char const *const *argv)
	fill the parameter list from argc, argv command line args More...
Double	getDouble (const String &key)
	Get the double value of the parameter (or 0.0 if unknown key). More...
Block< Double >	getDoubleArray (const String &key)
	Get the Block<double> value of the parameter (or default Block if unknown key). More...
Int	getInt (const String &key)
	Get the int value of the parameter (or 0 if unknown key). More...
Block< Int >	getIntArray (const String &key)
	Get the Block<int> value of parameter (or default Block if unknown key) If the program is in prompt mode, ask the user for the value. More...
String	getString (const String &key)
	Get the String value of the parameter (or "" if unknown key). More...
Bool	getBool (const String &key)
	Get the boolean value of the parameter (or FALSE if unknown key). More...
Int	count () const
	Get the total number of parameters of this program. More...
Bool	debug (Int l) const
	See if the current debug level is thresholded. More...
Bool	put (const String &key, const String &value)
	Set a new value for an existing named parameter Returns FALSE if key is an unknown parameter name. More...
Bool	put (const String &keyval)
	The single argument is of the form ‘key=value’, where key is a valid parameter name. More...
void	version (const String &)
	Set version string for announcements. More...
void	announce ()
	Announce program and version. More...

Static Public Member Functions
static Vector< Bool >	makeMaskFromRanges (const String &ranges, uInt length, Bool oneRelative=False)
	Turn a string in the form "5,7,9-11,13,2-4" into a Vector<Bool>, where each specified position or range, is set to True and every other position is set to False. More...

Private Member Functions
Int	getParam (const String &key) const
	Get the index of the named parameter (-1 if unknown key). More...
void	prompt (Param &parameter) const
	Prompt the user for a value for the parameter. More...
void	envCreate (const Char *env, const String &key, const String &def)
	Bind an environment variable to a parameter. More...
void	createPar (Int, const String &, const String &, const String &, const String &, const String &, const String &)
	The actual creation of a new (system/program) parameter. More...
void	keys ()
	output to stdout a listing of all "key=value" pairs. More...

Private Attributes
std::vector< Param >	parList_p
	container of parameters More...
String	version_id
	version id More...
Bool	is_closed
	parameter creation allowed? More...
Bool	do_prompt
	ask user for parameter value? More...
Int	debug_level
	threshold value for debug output More...
String	help_mode
	"prompt" or "keys" indicates the various types of help. More...
Int	p_count
	count of program parameters More...

Detailed Description

Input.h: A simple command-line argument method for applications.

Intended use:

Public interface

Review Status

Reviewed By:

UNKNOWN

Date Reviewed:

before2004/08/25

Test programs:

tInput

Prerequisite

• none noted

Etymology

The Input class name is a reflection of it's role as the early command line user interface for Casacore applications. This class provides "inputs" in the form "key=value" or "-key value."

Synopsis

The Input class is a holder of parameters, either automatically assigned values or altered at the execution of the program which utilizes them. The parameters are associations of String "keys" to "values". The parameters may be used as internal values during the program's run. The shell command

shell% myexecutable limits=1000 happy=True

would run "myexecutable" and set the internal parameter "limits" to a value of 1000 and "happy" to True.

The Input class is instantiated by a constructor with a single Int argument which, when non-zero, switches on the filling of the keys "debug" and "help" from environment variables. These two keys always exist in an instance of Input. No argument to the Input constructor defaults to "debug" and "help" being set to zero.

The default existance of the help parameter allows the user to specify predefined modes for the "help" key. The argument "help=prompt" turns on prompting for parameter values not specified on the command-line. In such an instance, the optional String arguments to Input::create become important. The argument "help=keys" will print to standard output a list of all the parameters.

The default existance of the debug parameter allows the user to specify levels of debugging, where 0 implies none and higher integers means more. The usage would be as follows:

Input inp;
// this will execute the block only for values higher than 5
if(inp.debug(5)) 
{  
// do debugging stuff here
}

Additional parameters must be created inside the main block (or deeper) of your application. The member function create() is overloaded to accept from one to six String arguments. All but the first are optional. However, should the user decide to call any of the get() functions which return a String, that String will be empty. In this case it is assumed that all values will be filled from the command line. Some examples:

int main(int argc,const char* argv[])
{
Input inp;
// Create a parameter called "foo" which defaults to True.
inp.create("foo", "True");
// Create a parameter called "iterbound" which defaults to 2000 and
// has a help String used in cases of prompting.
inp.create("iterbound", "2000", "The upper boundary of the iterator");
// Create a normalising value with a range, type, and unit.
inp.create("dividend", "10000", The normalization factor of the chutspah",
"0-100000", "Double", "clean steps");

The parameters are "filled" from the command line arguments by the member function ReadArguments(int argc, const char* argv[]). If an argument is not defined within the main block but specified at the command line, an exception is thrown.

inp.readArguments(argc, argv);

Finally, the values of the various parameter's are utilized by calling the Input::getWhatever(key) member functions. They return either a String or are converted to the data type chosen by the "whatever" in the name of the function. The value associated with the passed key is returned.

// get a boolean
if(inp.getBool("foo")
// get an iteration boundary
for(Int i=0; i<inp.getInt("iterbound"); i++) {
// get a double
chutspah /= inp.getDouble("dividend");
}

Optional items include:

1. specifying a version inp.version("$ID:"); will print at run time the version of the program being run.
2. run time checking of ranges inp.makeMaskFromRanges(const String &ranges, uInt length, Bool oneRelative=False);

Example

#include <casacore/casa/Inputs/Input.h>
int main(int argc, const char* argv[]) 
{
// instantiate an Input.  The integer argument of 1 to the ctor builds 
// the system parameters "debug" and "help" and sets their values to the
// shell environment variables DEBUG and HELP.
Input inp(1);
// set the version to be automatically expanded by the RCS.  This will
// print the version at run time.
inp.version("$ID:$");
// We will now create some parameters.
// Create a parameter with no default value i.e. it must be set by a 
// command line argument.
inp.create("test");
// Create a parameter with a default value.
inp.create("file", "$AIPSROOT/data.txt");
// Create a parameter with a help String which will be displayed when in
// the prompted entry mode.
inp.create("ubound", "1000", "The number of iterations to clean.");
// Create a parameter with a range of acceptable values.  Note: checking
// must be done by the user as this isn't coded in.
inp.create("gainstride", "0.5", "The factor by which the Clean strides.",
"Double", "0-1.0");
// Create a parameter with a unit String.  Note: checking must be done
// by the user as this test isn't coded in.
String help("The velocity of the Earth in the direction of the object.");
inp.create("velocity", "2.89e+05", help, "Double", "0-3.0e+06", "m/s");
// Now we close parameter creation and get the values from the command line
// arguments.
inp.readArguments(argc, argv);
// Now we may utilize the values from the paramters we have created.
// Here we are getting a boolean from the parameter with the key "test".
if(inp.getBool("test") {
// Here we get a String from the parameter with the key "file".
Image myImage(inp.getString("file"));
// Here we set the boundary of the loop.
for(Int i=0;i<inp.getInt("ubound"), i++) {
// Here we set a value to the number of baselines.
Int baseline = inp.getInt("baseline");
// Here we set the gain stride.
Cleaner.gain(inp.getDouble("gainstride"));
// lets add a debugging block
if(inp.debug(5)) cout << "the chutspah is " << chutspah << endl;
}
}

Motivation

In the earliest days of the old AIPS++ project, the desire to start coding right away led to the need for a user interface. The preexistant C language method of argc/argv was enclosed in an object for easier use.

Definition at line 202 of file Input.h.

Constructor & Destructor Documentation

Input()

casacore::Input::Input

(

Int

createEnv = 0

)

The default constructor enables the creation of parameters.

If the optional Int argument is non-zero, the parameters "help" and "debug" are created from their shell environment values. This puts the program in no-prompt mode unless environment variable HELP is defined with value "prompt". The output debug level is set according to the value of the environment variable DEBUG.

~Input()

casacore::Input::~Input

(

)

Destructor.

Member Function Documentation

announce()

void casacore::Input::announce

(

)

Announce program and version.

close()

void casacore::Input::close

(

)

Disable the creation of parameters.

Highly recommended, but not required. readArguments calls it when filling the values from argv[].

count()

Int casacore::Input::count

(

)

const

Get the total number of parameters of this program.

create() [1/6]

void casacore::Input::create

(

const String &

key

)

Create a new parameter, either from scratch or looking it up from an internal list of templates.

The function also checks whether parameters can still be created, and whether key is unique for the program. The value, help and remaining arguments are all optional.
Note: The multiple definitions are to allow default values

create() [2/6]

void casacore::Input::create	(	const String &	key,
		const String &	value
	)

create() [3/6]

void casacore::Input::create	(	const String &	key,
		const String &	value,
		const String &	help
	)

create() [4/6]

void casacore::Input::create	(	const String &	key,
		const String &	value,
		const String &	help,
		const String &	type
	)

create() [5/6]

void casacore::Input::create	(	const String &	key,
		const String &	value,
		const String &	help,
		const String &	type,
		const String &	range
	)

create() [6/6]

void casacore::Input::create	(	const String &	key,
		const String &	value,
		const String &	help,
		const String &	type,
		const String &	range,
		const String &	unit
	)

createPar()

void casacore::Input::createPar ( Int  , const String &  , const String &  , const String &  , const String &  , const String &  , const String &    )

private

The actual creation of a new (system/program) parameter.

debug()

Bool casacore::Input::debug ( Int  l ) const

inline

See if the current debug level is thresholded.

Definition at line 270 of file Input.h.

References debug_level, casacore::False, and casacore::True.

envCreate()

void casacore::Input::envCreate ( const Char *  env, const String &  key, const String &  def  )

private

Bind an environment variable to a parameter.

getBool()

Bool casacore::Input::getBool

(

const String &

key

)

Get the boolean value of the parameter (or FALSE if unknown key).

If the program is in prompt mode, ask the user for the value.

getDouble()

Double casacore::Input::getDouble

(

const String &

key

)

Get the double value of the parameter (or 0.0 if unknown key).

If the program is in prompt mode, ask the user for the value.

getDoubleArray()

Block<Double> casacore::Input::getDoubleArray

(

const String &

key

)

Get the Block<double> value of the parameter (or default Block if unknown key).

If the program is in prompt mode, ask the user for the value.

getInt()

Int casacore::Input::getInt

(

const String &

key

)

Get the int value of the parameter (or 0 if unknown key).

If the program is in prompt mode, ask the user for the value.

getIntArray()

Block<Int> casacore::Input::getIntArray

(

const String &

key

)

Get the Block<int> value of parameter (or default Block if unknown key) If the program is in prompt mode, ask the user for the value.

getParam()

Int casacore::Input::getParam ( const String &  key ) const

private

Get the index of the named parameter (-1 if unknown key).

Anywhere from 0.. if a key is found.

getString()

String casacore::Input::getString

(

const String &

key

)

Get the String value of the parameter (or "" if unknown key).

If the program is in prompt mode, ask the user for the value.

keys()

void casacore::Input::keys ( )

private

output to stdout a listing of all "key=value" pairs.

makeMaskFromRanges()

static Vector<Bool> casacore::Input::makeMaskFromRanges ( const String &  ranges, uInt  length, Bool  oneRelative = False  )

static

Turn a string in the form "5,7,9-11,13,2-4" into a Vector<Bool>, where each specified position or range, is set to True and every other position is set to False.

While the returned vector always has a zero origin, if oneRelative is True, all the numbers in the supplied string are decremented before use. Spaces in ranges are ignored, but otherwise ill-formed strings, or numbers that would fill in beyond the length of the Vector<Bool> results in an exception being thrown.

prompt()

void casacore::Input::prompt ( Param &  parameter ) const

private

Prompt the user for a value for the parameter.

If he gives a non-empty answer, set that value.

put() [1/2]

Bool casacore::Input::put	(	const String &	key,
		const String &	value
	)

Set a new value for an existing named parameter Returns FALSE if key is an unknown parameter name.

put() [2/2]

Bool casacore::Input::put

(

const String &

keyval

)

The single argument is of the form ‘key=value’, where key is a valid parameter name.

readArguments()

void casacore::Input::readArguments	(	int	argc,
		char const *const *	argv
	)

fill the parameter list from argc, argv command line args

version()

void casacore::Input::version

(

const String &

)

Set version string for announcements.

Member Data Documentation

debug_level

Int casacore::Input::debug_level

private

threshold value for debug output

Definition at line 333 of file Input.h.

Referenced by debug().

do_prompt

Bool casacore::Input::do_prompt

private

ask user for parameter value?

Definition at line 330 of file Input.h.

help_mode

String casacore::Input::help_mode

private

"prompt" or "keys" indicates the various types of help.

Definition at line 336 of file Input.h.

is_closed

Bool casacore::Input::is_closed

private

parameter creation allowed?

Definition at line 327 of file Input.h.

p_count

Int casacore::Input::p_count

private

count of program parameters

Definition at line 339 of file Input.h.

parList_p

std::vector<Param> casacore::Input::parList_p

private

container of parameters

Definition at line 321 of file Input.h.

version_id

String casacore::Input::version_id

private

version id

Definition at line 324 of file Input.h.

---

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

• casa/Inputs/Input.h