class CliBuilder
extends Object
Provides a builder to assist the processing of command line arguments. Two styles are supported: dynamic api style (declarative method calls provide a mini DSL for describing options) and annotation style (annotations on an interface or class describe options).
Dynamic api style
Typical usage (emulate partial arg processing of unix command: ls -alt *.groovy):
def cli = new CliBuilder(usage:'ls')
cli.a('display all files')
cli.l('use a long listing format')
cli.t('sort by modification time')
def options = cli.parse(args)
assert options // would be null (false) on failure
assert options.arguments() == ['*.groovy']
assert options.a && options.l && options.t
The usage message for this example (obtained using cli.usage()) is shown below:
usage: ls
-a display all files
-l use a long listing format
-t sort by modification time
An underlying parser that supports what is called argument 'bursting' is used
by default. Bursting would convert '-alt' into '-a -l -t' provided no long
option exists with value 'alt' and provided that none of 'a', 'l' or 't'
takes an argument (in fact the last one is allowed to take an argument).
The bursting behavior can be turned off by using an
alternate underlying parser. The simplest way to achieve this is by using
the deprecated GnuParser from Commons CLI with the parser property on the CliBuilder,
i.e. include parser: new GnuParser() in the constructor call.
Another example (partial emulation of arg processing for 'ant' command line):
def cli = new CliBuilder(usage:'ant [options] [targets]',
header:'Options:')
cli.help('print this message')
cli.logfile(args:1, argName:'file', 'use given file for log')
cli.D(args:2, valueSeparator:'=', argName:'property=value',
'use value for given property')
def options = cli.parse(args)
...
Usage message would be:
usage: ant [options] [targets]
Options:
-D <property=value> use value for given property
-help print this message
-logfile <file> use given file for log
And if called with the following arguments '-logfile foo -Dbar=baz target'
then the following assertions would be true:
assert options // would be null (false) on failure
assert options.arguments() == ['target']
assert options.Ds == ['bar', 'baz']
assert options.logfile == 'foo'
Note the use of some special notation. By adding 's' onto an option
that may appear multiple times and has an argument or as in this case
uses a valueSeparator to separate multiple argument values
causes the list of associated argument values to be returned.
Another example showing long options (partial emulation of arg processing for 'curl' command line):
def cli = new CliBuilder(usage:'curl [options] <url>')
cli._(longOpt:'basic', 'Use HTTP Basic Authentication')
cli.d(longOpt:'data', args:1, argName:'data', 'HTTP POST data')
cli.G(longOpt:'get', 'Send the -d data with a HTTP GET')
cli.q('If used as the first parameter disables .curlrc')
cli._(longOpt:'url', args:1, argName:'URL', 'Set URL to work with')
Which has the following usage message:
usage: curl [options] <url>
--basic Use HTTP Basic Authentication
-d,--data <data> HTTP POST data
-G,--get Send the -d data with a HTTP GET
-q If used as the first parameter disables .curlrc
--url <URL> Set URL to work with
This example shows a common convention. When mixing short and long names, the
short names are often one character in size. One character options with
arguments don't require a space between the option and the argument, e.g.
-Ddebug=true. The example also shows
the use of '_' when no short option is applicable.
Also note that '_' was used multiple times. This is supported but if any other shortOpt or any longOpt is repeated, then the behavior is undefined.
Short option names may not contain a hyphen. If a long option name contains a hyphen, e.g. '--max-wait' then you can either
use the long hand method call options.hasOption('max-wait') or surround
the option name in quotes, e.g. options.'max-wait'.
Although CliBuilder on the whole hides away the underlying library used for processing the arguments, it does provide some hooks which let you make use of the underlying library directly should the need arise. For example, the last two lines of the 'curl' example above could be replaced with the following:
import org.apache.commons.cli.*
... as before ...
cli << new Option('q', false, 'If used as the first parameter disables .curlrc')
cli << Option.builder().longOpt('url').hasArg().argName('URL').
desc('Set URL to work with').build()
...
CliBuilder also supports Argument File processing. If an argument starts with
an '@' character followed by a filename, then the contents of the file with name
filename are placed into the command line. The feature can be turned off by
setting expandArgumentFiles to false. If turned on, you can still pass a real
parameter with an initial '@' character by escaping it with an additional '@'
symbol, e.g. '@@foo' will become '@foo' and not be subject to expansion. As an
example, if the file temp.args contains the content:
-arg1
paramA
paramB paramC
Then calling the command line with:
someCommand- temp.args:
- -arg2 paramD
Is the same as calling this:
someCommand -arg1 paramA paramB paramC -arg2 paramD
This feature is particularly useful on operating systems which place limitations
on the size of the command line (e.g. Windows). The feature is similar to
the 'Command Line Argument File' processing supported by javadoc and javac.
Consult the corresponding documentation for those tools if you wish to see further examples.
Supported Option Properties:
argName: String
longOpt: String
args: int or String
optionalArg: boolean
required: boolean
type: Class
valueSeparator: char
convert: Closure
defaultValue: String
See Option for the meaning of most of these properties
and CliBuilderTest for further examples.
Annotation style with an interface
With this style an interface is defined containing an annotated method for each option. It might look like this (following roughly the earlier 'ls' example):
import groovy.cli.Option
import groovy.cli.Unparsed
interface OptionInterface {
@Option(shortName='a', description='display all files') boolean all()
@Option(shortName='l', description='use a long listing format') boolean longFormat()
@Option(shortName='t', description='sort by modification time') boolean time()
@Unparsed List remaining()
}
Then this description is supplied to CliBuilder during parsing, e.g.:
def args = '-alt *.groovy'.split() // normally from commandline itself
def cli = new CliBuilder(usage:'ls')
def options = cli.parseFromSpec(OptionInterface, args)
assert options.remaining() == ['*.groovy']
assert options.all() && options.longFormat() && options.time()
Annotation style with a class
With this style a user-supplied instance is used. Annotations on that instance's class members (properties and setter methods) indicate how to set options and provide the option details using annotation attributes. It might look like this (again using the earlier 'ls' example):
import groovy.cli.Option
import groovy.cli.Unparsed
class OptionClass {
@Option(shortName='a', description='display all files') boolean all
@Option(shortName='l', description='use a long listing format') boolean longFormat
@Option(shortName='t', description='sort by modification time') boolean time
@Unparsed List remaining
}
Then this description is supplied to CliBuilder during parsing, e.g.:
def args = '-alt *.groovy'.split() // normally from commandline itself
def cli = new CliBuilder(usage:'ls')
def options = new OptionClass()
cli.parseFromInstance(options, args)
assert options.remaining == ['*.groovy']
assert options.all && options.longFormat && options.time
| Type | Name and description |
|---|---|
boolean |
expandArgumentFilesWhether arguments of the form ' @filename' will be expanded into the arguments contained within the file named filename (default true). |
String |
footerOptional additional message for usage; displayed after the options are displayed. |
HelpFormatter |
formatterNormally set internally but can be overridden if you want to customise how the usage message is displayed. |
String |
headerOptional additional message for usage; displayed after the usage summary but before the options are displayed. |
Options |
optionsNot normally accessed directly but full access to underlying options if needed. |
CommandLineParser |
parserNormally set internally but allows you full customisation of the underlying processing engine. |
Boolean |
posixTo change from the default PosixParser to the GnuParser, set this to false. |
Map<String, TypedOption> |
savedTypeOptions |
boolean |
stopAtNonOptionIndicates that option processing should continue for all arguments even if arguments not recognized as options are encountered (default true). |
String |
usageUsage summary displayed as the first line when cli.usage() is called. |
int |
widthAllows customisation of the usage message width. |
PrintWriter |
writerDefaults to stdout but you can provide your own PrintWriter if desired. |
| Constructor and description |
|---|
CliBuilder() |
| Type Params | Return Type | Name and description |
|---|---|---|
|
void |
addOptionsFromAnnotations(Class optionClass, boolean namesAreSetters) |
|
static Map |
adjustDetails(Map m) |
|
static Object |
expandArgumentFiles(Object args) |
|
Object |
invokeMethod(String name, Object args)Internal method: Detect option specification method calls. |
<T> |
TypedOption<T> |
option(Map args, Class<T> type, String description) |
|
Option |
option(Object shortname, Map details, Object info)Internal method: How to create an option from the specification. |
|
OptionAccessor |
parse(Object args)Make options accessible from command line args with parser. |
<T> |
T |
parseFromInstance(T optionInstance, Object args)Given an instance containing members with annotations, derive the options specification. |
<T> |
T |
parseFromSpec(Class<T> optionsClass, String[] args)Given an interface containing members with annotations, derive the options specification. |
|
Object |
setOptionsFromAnnotations(Object cli, Class optionClass, Object t, boolean namesAreSetters) |
|
void |
usage()Print the usage message with writer (default: System.out) and formatter (default: HelpFormatter) |
Whether arguments of the form '@filename' will be expanded into the arguments contained within the file named filename (default true).
Optional additional message for usage; displayed after the options are displayed.
Normally set internally but can be overridden if you want to customise how the usage message is displayed.
Optional additional message for usage; displayed after the usage summary but before the options are displayed.
Not normally accessed directly but full access to underlying options if needed.
Normally set internally but allows you full customisation of the underlying processing engine.
To change from the default PosixParser to the GnuParser, set this to false. Ignored if the parser is explicitly set.
Indicates that option processing should continue for all arguments even if arguments not recognized as options are encountered (default true).
Usage summary displayed as the first line when cli.usage() is called.
Allows customisation of the usage message width.
Defaults to stdout but you can provide your own PrintWriter if desired.
Internal method: Detect option specification method calls.
Internal method: How to create an option from the specification.
Make options accessible from command line args with parser. Returns null on bad command lines after displaying usage message.
Given an instance containing members with annotations, derive the options specification.
Given an interface containing members with annotations, derive the options specification.
Print the usage message with writer (default: System.out) and formatter (default: HelpFormatter)
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