How to ignore/exclude some files/directory from linting in angular cli

From Angular6+, .angular-cli.json has been replaced by angular.json, but you can still add the exclude path in its lint part.

"lint": {
      "builder": "@angular-devkit/build-angular:tslint",
      "options": {
        "tsConfig": [
          "src/tsconfig.app.json",
          "src/tsconfig.spec.json"
        ],
        "exclude": [
          "**/node_modules/**"      // excluded directories
        ]
      }
    }

According to the angular-cli issue#5063, you can add the exclude path in .angular-cli.json like this:

"lint": [
{
  "project": "src/tsconfig.app.json",
  "exclude": "**/node_modules/**/*"   // the node_modules for example
}]