{"id":13482583,"url":"https://github.com/mosop/optarg","last_synced_at":"2026-01-17T03:38:06.432Z","repository":{"id":89452489,"uuid":"57125814","full_name":"mosop/optarg","owner":"mosop","description":"Yet another Crystal library for parsing command-line options and arguments.","archived":false,"fork":false,"pushed_at":"2019-08-07T12:20:43.000Z","size":251,"stargazers_count":26,"open_issues_count":5,"forks_count":7,"subscribers_count":2,"default_branch":"master","last_synced_at":"2024-08-01T17:32:36.126Z","etag":null,"topics":[],"latest_commit_sha":null,"homepage":"","language":"Crystal","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"mit","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/mosop.png","metadata":{"files":{"readme":"README.md","changelog":"CHANGELOG.md","contributing":null,"funding":null,"license":"LICENSE","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null}},"created_at":"2016-04-26T12:20:10.000Z","updated_at":"2023-07-12T04:22:50.000Z","dependencies_parsed_at":"2023-03-09T10:30:51.730Z","dependency_job_id":null,"html_url":"https://github.com/mosop/optarg","commit_stats":null,"previous_names":[],"tags_count":51,"template":false,"template_full_name":null,"repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/mosop%2Foptarg","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/mosop%2Foptarg/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/mosop%2Foptarg/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/mosop%2Foptarg/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/mosop","download_url":"https://codeload.github.com/mosop/optarg/tar.gz/refs/heads/master","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":222262393,"owners_count":16957572,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":[],"created_at":"2024-07-31T17:01:03.514Z","updated_at":"2026-01-17T03:38:06.426Z","avatar_url":"https://github.com/mosop.png","language":"Crystal","readme":"# optarg\n\nYet another Crystal library for parsing command-line options and arguments.\n\noptarg is good enough for parsing options. However there's no feature for formatting help, subcommands... etc. If you prefer a more feature-rich library, try [cli](https://github.com/mosop/cli).\n\n[![CircleCI](https://circleci.com/gh/mosop/optarg.svg?style=shield)](https://circleci.com/gh/mosop/optarg)\n\n## Installation\n\nAdd this to your application's `shard.yml`:\n\n```yaml\ndependencies:\noptarg:\n  github: mosop/optarg\n```\n\n\u003ca name=\"code_samples\"\u003e\u003c/a\u003e\n\n## Code Samples\n\n### Accessor\n\n```crystal\nclass Model \u003c Optarg::Model\n  string \"--foo\"\nend\n\nresult = Model.parse(%w(--foo bar))\nresult.foo # =\u003e \"bar\"\n```\n\n### Nilable Accessor\n\n```crystal\nclass Model \u003c Optarg::Model\n  string \"--foo\"\nend\n\nresult = Model.parse(%w())\nresult.foo? # =\u003e nil\nresult.foo # raises KeyError\n```\n\n### Synonyms\n\n```crystal\nclass Model \u003c Optarg::Model\n  string %w(-f --file)\nend\n\nresult = Model.parse(%w(-f foo.cr))\nresult.f # =\u003e \"foo.cr\"\nresult.file # =\u003e \"foo.cr\"\n```\n\n### Boolean\n\n```crystal\nclass Model \u003c Optarg::Model\n  bool \"-b\"\nend\n\nresult = Model.parse(%w(-b))\nresult.b? # =\u003e true\n```\n\n### Array\n\n```crystal\nclass Model \u003c Optarg::Model\n  array \"-e\"\nend\n\nresult = Model.parse(%w(-e foo -e bar -e baz))\nresult.e # =\u003e [\"foo\", \"bar\", \"baz\"]\n```\n\n### Concatenation\n\n```crystal\nclass Model \u003c Optarg::Model\n  bool \"-a\"\n  bool \"-b\"\nend\n\nresult = Model.parse(%w(-ab))\nresult.a? # =\u003e true\nresult.b? # =\u003e true\n```\n\n### Default Value\n\n```crystal\nclass Model \u003c Optarg::Model\n  string \"-s\", default: \"string\"\n  bool \"-b\", default: true\n  array \"-a\", default: %w(1 2 3)\nend\n\nresult = Model.parse(%w())\nresult.s  # =\u003e \"string\"\nresult.b? # =\u003e true\nresult.a  # =\u003e [\"1\", \"2\", \"3\"]\n```\n\n### Negation\n\n```crystal\nclass Model \u003c Optarg::Model\n  bool \"-b\", default: true, not: \"-B\"\nend\n\nresult = Model.parse(%w(-B))\nresult.b? # =\u003e false\n```\n\n### Arguments\n\n```crystal\nclass Model \u003c Optarg::Model\n  string \"-s\"\n  bool \"-b\"\nend\n\nresult = Model.parse(%w(foo -s string bar -b baz))\nresult.args # =\u003e [\"foo\", \"bar\", \"baz\"]\n```\n\n### Named Arguments\n\n```crystal\nclass Model \u003c Optarg::Model\n  arg \"src_dir\"\n  arg \"build_dir\"\nend\n\nresult = Model.parse(%w(/path/to/src /path/to/build and more))\nresult.args.src_dir # =\u003e \"/path/to/src\"\nresult.args.build_dir # =\u003e \"/path/to/build\"\nresult.args # =\u003e [\"/path/to/src\", \"/path/to/build\", \"and\", \"more\"]\nresult.named_args # =\u003e {\"src_dir\" =\u003e \"/path/to/src\", \"build_dir\" =\u003e \"/path/to/build\"}\nresult.nameless_args # =\u003e [\"and\", \"more\"]\n```\n\n### Argument Array\n\n```crystal\nclass Model \u003c Optarg::Model\n  arg \"arg\"\n  arg_array \"item\"\nend\n\nresult = Model.parse(%w(foo bar baz))\nresult.arg # =\u003e \"foo\"\nresult.item # =\u003e [\"bar\", \"baz\"]\n```\n\n### Inheritance (Reusing Models)\n\n```crystal\nabstract class Animal \u003c Optarg::Model\n  bool \"--sleep\"\nend\n\nclass Cat \u003c Animal\n  bool \"--mew\"\nend\n\nclass Dog \u003c Animal\n  bool \"--woof\"\nend\n\nCat.parse(%w()).responds_to?(:sleep?) # =\u003e true\nDog.parse(%w()).responds_to?(:sleep?) # =\u003e true\n```\n\n### Handler\n\n```crystal\nclass Model \u003c Optarg::Model\n  on(\"--goodbye\") { goodbye! }\n\n  def goodbye!\n    raise \"Goodbye, world!\"\n  end\nend\n\nModel.parse %w(--goodbye) # raises \"Goodbye, world!\"\n```\n\n### Required Arguments and Options\n\n```crystal\nclass Profile \u003c Optarg::Model\n  string \"--birthday\", required: true\nend\n\nProfile.parse %w() # raises a RequiredOptionError exception.\n```\n\n```crystal\nclass Compile \u003c Optarg::Model\n  arg \"source_file\", required: true\nend\n\nCompile.parse %w() # raises a RequiredArgumentError exception.\n```\n\n### Minimum Length of Array\n\n```crystal\nclass Multiply \u003c Optarg::Model\n  array \"-n\", min: 2\n\n  def run\n    puts options.n.reduce{|n1, n2| n1 * n2}\n  end\nend\n\nMultiply.parse %w(-n 794) # raises a MinimumLengthError exception.\n```\n\n### Custom Initializer\n\n```crystal\nclass The\n  def message\n    \"Someday again!\"\n  end\nend\n\nclass Model \u003c Optarg::Model\n  def initialize(argv, @the : The)\n    super argv\n  end\n\n  on(\"--goodbye\") { raise @the.message }\nend\n\nModel.parse(%w(--goodbye), The.new) # raises \"Someday again!\"\n```\n\n### Stop and Termination\n\n```crystal\nclass Model \u003c Optarg::Model\n  bool \"-b\", stop: true\nend\n\nresult = Model.parse(%w(foo -b bar))\nresult.b? # =\u003e true\nresult.args # =\u003e [\"foo\"]\nresult.unparsed_args # =\u003e [\"bar\"]\n```\n\n```crystal\nclass Model \u003c Optarg::Model\n  terminator \"--\"\nend\n\nresult = Model.parse(%w(foo -- bar))\nresult.args # =\u003e [\"foo\"]\nresult.unparsed_args # =\u003e [\"bar\"]\n```\n\n### Validating Inclusion\n\n```crystal\nclass Trip \u003c Optarg::Model\n  arg \"somewhere_warm\", any_of: %w(tahiti okinawa hawaii)\nend\n\nTrip.parse(%w(gotland)) # =\u003e raises an error\n```\n\n### Custom Validation\n\n```crystal\nclass Hello \u003c Optarg::Model\n  arg \"smiley\"\n\n  Parser.on_validate do |parser|\n    parser.invalidate! \"That's not a smile.\" if parser.args.smiley != \":)\"\n  end\nend\n\nHello.parse %w(:P) # =\u003e raises \"That's not a smile.\"\n```\n\n## Usage\n\n```crystal\nrequire \"optarg\"\n```\n\nand see:\n\n* [Code Samples](#code_samples)\n* [Wiki](https://github.com/mosop/optarg/wiki)\n* [API Document](http://mosop.me/optarg/Optarg.html)\n\n## Release Notes\n\nSee [Releases](https://github.com/mosop/optarg/releases).\n","funding_links":[],"categories":["Cli Builders","CLI Builders","\u003ca name=\"Crystal\"\u003e\u003c/a\u003eCrystal"],"sub_categories":[],"project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fmosop%2Foptarg","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fmosop%2Foptarg","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fmosop%2Foptarg/lists"}