Class GetOpt

Object
  GetOpt

public class GetOpt
extends Object

Java version of GNU getopt.

Nested Class Summary

static class

GetOpt.LongOption A record used in a table of option descriptions passed to a constructor of GetOpt.

Field Summary

int	longind Index in longopts of a long-named option found.
static int	NO_ARG A value for LongOption.has Arg meaning "option has no argument".
static int	OPT_ARG A value for LongOption.has Arg meaning "option has an optional argument".
String	optarg For communication from nextOpt() to the caller.
boolean	opterr If set to false, do not print messages to System.err for unrecognized options.
int	optind Index in argv of the next element to be scanned.
char	optopt Set to an option character which was unrecognized.
static int	REQ_ARG A value for LongOption.has Arg meaning "option has a required argument".

Constructor Summary

GetOpt(String progname, String[] argv, String shortopts)
Create a new option parser.

GetOpt(String progname, String[] argv, String shortopts, GetOpt.LongOption[] longopts)
Create a new option parser.

GetOpt(String progname, String[] argv, String shortopts, GetOpt.LongOption[] longopts, boolean longonly)
Create a new option parser.

Method Summary

static void	main(String[] ignore) Main program for testing.
int	nextOpt() Return the next option.

Methods inherited from class Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

NO_ARG

public static final int NO_ARG

A value for LongOption.has Arg meaning "option has no argument".

See Also:

Constant Field Values

REQ_ARG

public static final int REQ_ARG

A value for LongOption.has Arg meaning "option has a required argument".

See Also:

Constant Field Values

OPT_ARG

public static final int OPT_ARG

A value for LongOption.has Arg meaning "option has an optional argument".

See Also:

Constant Field Values

optind

public int optind

Index in argv of the next element to be scanned. When nextOption() returns -1, this is the index of the first of the non-option elements that the caller should itself scan (argv.length, if there are no non-option arguments). Otherwise, optind communicates from one call to the next how much of argv has been scanned thus far.

longind

public int longind

Index in longopts of a long-named option found. It is only valid when long-named option has been found in the most recent call to nextOpt().

optarg

public String optarg

For communication from nextOpt() to the caller. When nextOpt() finds an option that takes an argument, the argument value is returned here.

opterr

public boolean opterr

If set to false, do not print messages to System.err for unrecognized options. By default, it is set to true.

optopt

public char optopt

Set to an option character which was unrecognized.

Constructor Detail

GetOpt

public GetOpt(String progname,
              String[] argv,
              String shortopts,
              GetOpt.LongOption[] longopts,
              boolean longonly)

Create a new option parser.

Parameters:

progname - the name of the program (for error messages)

argv - an array of command-line arguments

shortopts - a string of short option flags. A single colon following a flag indicates it has a mandatory argument; a double colon indicates an optional argument.

longopts - a table of long option descriptors

longonly - if true, indicates athat -flag should be treated as a long flag, like --flag, rather than four short flags.

GetOpt

public GetOpt(String progname,
              String[] argv,
              String shortopts)

Create a new option parser. Equivalent to GetOpt(progname, argv, shortopts, null, false)

Parameters:

progname - the name of the program (for error messages)

argv - an array of command-line arguments

shortopts - a string of short option flags. A single colon following a flag indicates it has a mandatory argument; a double colon indicates an optional argument.

GetOpt

public GetOpt(String progname,
              String[] argv,
              String shortopts,
              GetOpt.LongOption[] longopts)

Create a new option parser. Equivalent to GetOpt(progname, argv, shortopts, longopts, false)

Parameters:

progname - the name of the program (for error messages)

argv - an array of command-line arguments

shortopts - a string of short option flags. A single colon following a flag indicates it has a mandatory argument; a double colon indicates an optional argument.

longopts - a table of long option descriptors

Method Detail

nextOpt

public int nextOpt()

Return the next option. If there are no more options, return -1. Other information may be returned in the fields optind, longind, optarg, and optopt.

Returns:

-1 if there are no more options; otherwise a character indicating which option was found (longopts[longind].val for long options) or '?' for errors.

main

public static void main(String[] ignore)

Main program for testing.

Parameters:

ignore - ignored