feat: add --version cli option

.editorconfig

@@ -0,0 +1,14 @@
+root = true
+
+[*]
+
+indent_style = space
+indent_size = 2
+
+end_of_line = lf
+charset = utf-8
+trim_trailing_whitespace = true
+insert_final_newline = true
+
+[*.md]
+trim_trailing_whitespace = false

README.md

@@ -19,10 +19,11 @@ Start unit tests with `npm test`, `yarn run test`, or `docker-compose -f docker-
 Usage: dockerfilelint [files | content..] [options]
 
 Options:
-  -o, --output  Specify the format to use for output of linting results. Valid values
-                are `json` or `cli` (default).                               [string]
-  -j, --json    Output linting results as JSON, equivalent to `-o json`.    [boolean]
-  -h, --help    Show help                                                   [boolean]
+  -o, --output   Specify the format to use for output of linting results. Valid values
+                 are `json` or `cli` (default).                               [string]
+  -j, --json     Output linting results as JSON, equivalent to `-o json`.    [boolean]
+  -v, --version  Show version number                                         [boolean]
+  -h, --help     Show help                                                   [boolean]
 
 Examples:
   dockerfilelint Dockerfile         Lint a Dockerfile in the current working

bin/dockerfilelint

@@ -17,12 +17,14 @@ var argv = require('yargs')
     desc: 'Output linting results as JSON, equivalent to `-o json`.',
     type: 'boolean'
   })
+  .alias('v', 'version')
+  .version(() => require('../package.json').version)
   .help().alias('h', 'help')
   .example('dockerfilelint Dockerfile', 'Lint a Dockerfile in the current working directory\n')
   .example('dockerfilelint test/example/* -j', 'Lint all files in the test/example directory and output results in JSON\n')
   .example(`dockerfilelint 'FROM latest'`, 'Lint the contents given as a string on the command line\n')
   .example('dockerfilelint < Dockerfile', 'Lint the contents of Dockerfile via stdin')
-  .wrap(85)
+  .wrap(86)
   .check(argv => {
     if (!argv.output && argv.json) argv.output = 'json'
     return true