# Source: https://github.com/aquasecurity/trivy/blob/main/docs/guide/configuration/skipping.md

# Selecting files for scanning

When scanning a target (image, code repository, etc), Trivy traverses all directories and files in that target and looks for known files to scan. For example, vulnerability scanner might look for `/lib/apk/db/installed` for Alpine APK scanning or `requirements.txt` file for Python pip scanning, and misconfiguration scanner might look for `Dockerfile` for Dockerfile scanning. This document explains how to control which files Trivy looks (including skipping files) for and how it should process them.

!!! note
    Selecting/skipping files is different from filtering/ignoring results, which is covered in the [Filtering document](./filtering.md)

## Skip Files and Directories

You can skip specific files and directories using the `--skip-files` and `--skip-dirs` flags.

For example:

```bash
trivy image --skip-files "/Gemfile.lock" --skip-dirs "/var/lib/gems/2.5.0/gems/http_parser.rb-0.6.0" quay.io/fluentd_elasticsearch/fluentd:v2.9.0
```

This feature is relevant for the following scanners:

|     Scanner      | Supported |
|:----------------:|:---------:|
|  Vulnerability   |     ✓     |
| Misconfiguration |     ✓     |
|      Secret      |     ✓     |
|     License      |     ✓     |

It's possible to specify glob patterns when referring to a file or directory. The glob expression follows the ["doublestar" library syntax](https://pkg.go.dev/github.com/bmatcuk/doublestar/v4@v4.8.1#readme-patterns).

Examples:

```bash
# skip any file named `bar` in the subdirectories of testdata
trivy image --skip-files "./testdata/*/bar" .
```

```bash
# skip any files with the extension `.tf` in subdirectories of foo at any depth
trivy config --skip-files "./foo/**/*.tf" .
```

```bash
# skip all subdirectories of the testdata directory.
trivy image --skip-dirs "./testdata/*" .
```

```bash
# skip subdirectories at any depth named `.terraform/`. 
# this will match `./foo/.terraform` or `./foo/bar/.terraform`, but not `./.terraform`
trivy config --skip-dirs "**/.terraform" .
```

Like any other flag, this is available as Trivy YAML configuration.

For example:

```yaml
image:
  skip-files:
    - foo
    - "testdata/*/bar"
  skip-dirs:
    - foo/bar/
    - "**/.terraform"
```

## Customizing file handling

You can customize which files Trivy scans and how it interprets them with the `--file-patterns` flag.
A file pattern configuration takes the following form: `<analyzer>:<path>`, such that files matching the `<path>` will be processed with the respective `<analyzer>`.

!!! Note
    `--file-patterns` flag doesn't disable the default file detection behavior of Trivy. It only adds the file detection based on the specified patterns.

For example:

```bash
trivy fs --file-patterns "pip:.requirements-test.txt" .
```

This feature is relevant for the following scanners:

|     Scanner      | Supported |
|:----------------:|:---------:|
|  Vulnerability   |     ✓     |
| Misconfiguration |     ✓     |
|      Secret      |           |
|     License      |   ✓[^1]   |

The list of analyzers can be found [here](https://github.com/aquasecurity/trivy/tree/{{ git.commit }}/pkg/fanal/analyzer/const.go).
Note that this flag is not applicable for parsers that accepts files of different extensions, for example the Terraform file parser which handles .tf and .tf.json files.


The file path can use a [regular expression](https://pkg.go.dev/regexp/syntax). For example:

```bash
# interpret any file with .txt extension as a python pip requirements file
trivy fs --file-patterns "pip:requirements-.*\.txt" .
```

The flag can be repeated for specifying multiple file patterns. For example:

```bash
# look for Dockerfile called production.docker and a python pip requirements file called requirements-test.txt
trivy fs --scanners misconfig,vuln --file-patterns "dockerfile:.production.docker" --file-patterns "pip:.requirements-test.txt" .
```

[^1]: Only work with the [license-full](../scanner/license.md) flag

## Avoid full filesystem traversal

In specific scenarios Trivy can avoid traversing the entire filesystem, which makes scanning faster and more efficient.
For more information see [here](../target/rootfs.md#performance-optimization)