Classes
class	util::CommandLineReader
	Implementation of an util::OptionReader for command line processing. More...

class	util::ConfigFileReader
	Implementation of an OptionReader for config file processing. More...

class	util::Option
	The base class for all options. More...

class	util::IntOption
	Hold an integer number. More...

class	util::FloatOption
	Hold a single precision number. More...

class	util::DoubleOption
	Hold a double precision number. More...

class	util::BoolOption
	Hold a boolean. Default value is toggled when the option is given. More...

class	util::StringOption
	Hold a string. More...

class	util::FloatArrayOption
	Hold an array of N floats. More...

class	util::DoubleArrayOption
	Hold an array of N doubles. More...

class	util::IntArrayOption
	Hold an array of N ints. More...

class	util::StringArrayOption

class	util::RegionArrayOption
	Hold a N-dim `Region`. More...

class	util::OptionParser
	Generic parser object for options. More...

class	util::OptionReader
	An abstract base class for sources feeding into util::OptionParser . More...

Functions
ostream &	operator<< (ostream &os, Option &op)

ostream &	operator<< (ostream &os, const OptionParser &op)

Detailed Description

The option parsing library consists of a set of classes derived from util::Option which describe the types of the options the program accepts, for example a string, a float, an array of floats, etc.

There are two option readers, one constructing a list of options from the command line, the util::CommandLineReader, and one constructing a list of options from a file, the util::ConfigFileReader. Both are derived from the generic util::OptionReader. They can also be used in combination, i.e. reading options from a file and allowing the user to override values via the command line. The example code below should make things clear.

When using the option parsing library, the first thing to do is to tell it what options a program accepts. This is done by adding Option objects to an instance of OptionParser. Each option will have a data type, and will hold a long option name (used on the command line with –long-option [value], an optional short option form (e.g. -l), a default value, and, optionally, a pointer to the data type where the option will store its value (a pointer to, e.g., a global variable, or a member of a struct.

Next, a program would tell the OptionParser to parse the options it was given on the command line or in the config file. The OptionParser uses an OptionReader to do the actual reading. The values can then be probed using OptionParser::getOption().

Any arguments passed on the command line without a preceding '-' or '–' AFTER the last option are considered "file name arguments" and can be retrieved from the CommandLineReader using CommandLineReader::fileArguments().

The command line syntax is as follows: –long-name or -s, arguments separated by a space from the option, array arguments separated by commas without space. Bool flags toggle their default value.

  program --find-things --this-number 2.0 --array 1,2,3 -v 5.0 -s hello file1 file2 file3

In a config file, the syntax is long-option-name = value. '#' is the comment character. Value syntax the same as for the command line.

 find-things  = TRUE   # true|false|TRUE|FALSE for bool options
 this-number  = 2.0    # a float option
 array        = 1,2,3  # an integer array
 value        = 5.0    # another float, -v is short form, in the file we give the long name
 string       = hello  # -s was the short form

This config file can then be used together with the command line like this:

  program --config-file program.conf --find-things --array 5,6,7 file1 file2 file3

So that the program will find –find-things to be FALSE and array to be 5,6,7 (both overridden on the command line) and the remaining options as given in the config file.

The OptionParser::printUsage() method generates properly formatted and annotated usage information:

 -h, --help <FLAG>                    [FALSE]
     Print usage information.

 -e, --expr <STRING>                  []
     The expression to evaluate. Mandatory. Function and variable
     names are case insensitive. The file operands are assigned to
     the variables in the expression in order.

 -o, --outfile <STRING>               [test.fits]
     Output filename.
 ...

To make everything clear, here is an example using just the command line.

*  // globals
*  bool help;
*  string outfile;
*  int    size[3];
*  CommandLineReader comline(argc, argv); // read from command line
*  OptionParser flags(&comline);
*  //                  type       --name    default  description             -short   ptr to value (optional)
*  flags.addOption(new BoolOption("help", "FALSE", "Print usage information.", 'h', &help) );
*  flags.addOption(new StringOption("outfile", "test.fits", "Output filename.", 'o', &outfile) );
*  flags.addOption(new IntArrayOption("size", "0,0,0", "Size array", 's', 3, &size[0]) );
*
*  flags.parseOptions();
*  list<string> files = comline.fileArguments(); // get the filenames
*  

Finally, here is a more complex example using first a config file and then allowing options to be overridden by the command line.

*  // globals
*  bool help;
*  string outfile;
*  int    size[3];
*
*  string cf = "";
*  // config file name should be the first command line argument:
*  if( argc >= 3 && (!strcmp(argv[1],"--config-file") || !strcmp(argv[1],"-c")) )
*     cf = argv[2];
*
*  try
*  {
*    ConfigFileReader cfgfile( cf );
*    OptionParser flags( &cfgfile );    // here we use the ConfigFileReader
*
*    //                  type       --name    default  description             -short   ptr to value (optional)
*    flags.addOption(new BoolOption("help", "FALSE", "Print usage information.", 'h', &help) );
*    flags.addOption(new StringOption("outfile", "test.fits", "Output filename.", 'o', &outfile) );
*    flags.addOption(new IntArrayOption("size", "0,0,0", "Size array", 's', 3, &size[0]) );
*
*    // read the config file
*    flags.parseOptions();
*
*    // then try again from the command line
*    CommandLineReader comline(argc, argv); // read from command line
*    flags.changeReader( &comline );
*    flags.parseOptions();
*  }
*  catch (exception& e)
*  {
*    flags.printUsage(cerr);
*    throw;
*  }
*  // finally, retrieve the file arguments
*  list<string> files = comline.fileArguments(); // get the filenames
*  

Function Documentation

ostream & operator<<	(	ostream &	os,
		Option &	op
	)

ostream & operator<<	(	ostream &	os,
		const OptionParser &	op
	)

  expr             | e |                            |
  help             | h |                      FALSE | FALSE
  outfile          | o |                  test.fits | test.fits
  propagate-errors | p |                      FALSE | FALSE
  size             | s |                      0,0,0 | 0,0,0
  verbose          | v |                      FALSE | FALSE

Classes

Functions

Detailed Description

Function Documentation