|
Project Information
Members
Featured
Downloads
Wiki pages
Links
|
Groovy Option ParserGOP is a command line option parsing alternative to CliBuilder. I wrote GOP for a couple reasons:
An example is the easiest explanation def parser = new org.computoring.gop.Parser(description: "An example parser demonstrating the features and uses of GOP.")
parser.with {
// support for required options
// required options cannot have default values, that doesn't make much sense
required 'f', 'foo-bar', [description: 'A required option with a short name, a long name, and a description']
// support for optional options
optional 'b', [
longName: 'bar-baz', // longName can be specified this way also
default: 'xyz',
description: 'An optional option with a short name, a long name, a default value, and a description'
]
// support for flag (boolean) options
flag 'c' // a flag option without a long name or a description, flags default to false
flag 'd', 'debug', [
default: true,
description: 'A flag option with a default value of true'
]
// short names are not required, pass in null
optional null, 'optional-long-opt', [ description: 'An optional option without a shortname.' ]
required null, 'required-long-opt', [ description: 'A required option without a shortname.' ]
// support for parameter validation. The parameter is passed to the validation closure. The value
// returned from the closure is assigned back to the option.
required 'i', 'count', [
description: 'A required, validated option',
validate: {
Integer.parseInt it // the value of the parsed option with be an Integer in this case
}
]
// Support for remainder validation. Whatever is remaining after the options are parsed is passed into
// the remainder closure. Whatever is returned from the closure is available as parser.remainder.
// In this case a command is required after parameters.
remainder {
if(!it) throw new IllegalArgumentException("missing command")
it
}
}
// typically, I'll call parse like this. If anything blows up I catch Exception and
// print the parser.usage to stderr and exit
try {
// A script at this point would call parse with the command line args,
// def params = parser.parse(args)
// '--' stops option parsing
def params = parser.parse("-f foo_value --debug --count 123 --required-long-opt wookie -- --not-an-option some other stuff".split())
// parsed as -f, referenced here as params.'foo-bar'
assert params.'foo-bar' == 'foo_value'
// -b not supplied, 'xyz' is the default value
assert params.b == 'xyz'
// -c not supplied, flag options default to false
assert params.c == false
// --debug was supplied and flag option set to true
assert params.debug == true
// -i and --count validate and convert their parsed value into an Integer
assert params.count instanceof Integer
assert params.i == 123
assert params.'required-long-opt' == 'wookie'
// verify the remainder contains everything after '--'
assert parser.remainder.join(' ') == '--not-an-option some other stuff'
}
catch( Exception e ) {
System.err << parser.usage
System.exit(1)
}The example above will generate usage output like this An example parser demonstrating the features and uses of GOP.
Required
-f, --foo-bar A required option with a short name, a long name, and a description
--required-long-opt A required option without a shortname.
-i, --count A required, validated option
Optional
-b, --bar-baz [xyz] An optional option with a short name, a long name, a default value, and a description
--optional-long-opt An optional option without a shortname.
Flags
-c [false]
-d, --debug [true] A flag option with a default value of trueA couple interesting features
|
|
|
