FOSSLight Prechecker

License Current python package version. GitHub Repository REUSE status

FOSSLight Prechecker is a tool used to check whether the copyright and license writing rules in source code are properly applied, and to supplement them if necessary.

How to Install

FOSSLight Prechecker can be installed using pip3. It is recommended to install it in a python 3.10 + virtualenv environment.

$ pip3 install fosslight_prechecker



How to Run

FOSSLight Prechecker provides the following four modes, each performing different functions for managing copyright and license information in source code.

  1. lint β€” Check whether the copyright and license writing rules in source code are complied with.
  2. convert β€” Convert sbom-info.yaml or oss-pkg-info.yaml to Fosslight_Report.xlsx format.
    • The contents of the yaml file are converted to the SRC Sheet of Fosslight_Report.xlsx.
  3. add β€” Add copyright, license, and download location information to files that are missing copyright or license information.
  4. download β€” Download the license text of each license specified in the sbom-info.yaml file as individual text files.
$ fosslight_prechecker [Mode] [option1] <arg1> [option2] <arg2>...

How to Run by Mode & Parameters

  • Required parameter : Modes
  • Optional parameter : Options 
 Usage
    ────────────────────────────────────────────────────────────────────
    fosslight_prechecker [modes] [options] <arguments>

    πŸ“ Description
    ────────────────────────────────────────────────────────────────────
    FOSSLight Prechecker checks and corrects copyright and license writing
    rules in source code. It can lint, add, convert, and
    download license information.

    πŸ“š Guide: https://fosslight.org/fosslight-guide/scanner/1_prechecker.html

    πŸ”§ Modes
    ────────────────────────────────────────────────────────────────────
    lint (default)         Check copyright and license writing rules compliance
    add                    Add missing license, copyright, and download location
    convert                Convert sbom-info.yaml to FOSSLight-Report.xlsx
    download               Download license text specified in sbom-info.yaml

    βš™οΈ  General Options
    ────────────────────────────────────────────────────────────────────
    -p <path>              Path to check (default: current directory)
    -o <file>              Output file name
    -f <format>            Result format (yaml, xml, html)
    -e <pattern>           Exclude paths from checking (files and directories)
                           (only works with 'lint' mode)
                           ⚠️  IMPORTANT: Always wrap in quotes to avoid shell expansion
                           Example: fosslight_prechecker -e "test/" "*.pyc"
    -h                     Show this help message
    -v                     Show version information
    -i                     Don't write log file and show progress bar
    --notice               Print the open source license notice text

    πŸ” Mode-Specific Options
    ────────────────────────────────────────────────────────────────────
    lint mode:
      -n                   Don't exclude venv*, node_modules, .*/, and
                           FOSSLight Scanner results from analysis

    add mode:
      -l <license>         Add license name in SPDX format (ex: "Apache-2.0")
      -c <copyright>       Add copyright text (ex: "2015-2021 LG Electronics Inc.")
      -u <url>             Add download location URL(ex: "https://www.sampleurl.com")

    download mode:
      -l <license>         License to be representative license

    πŸ’‘ Examples
    ────────────────────────────────────────────────────────────────────
    # Lint current directory (check compliance)
    fosslight_prechecker lint

    # Lint specific path with exclusions
    fosslight_prechecker lint -p /path/to/source -e "test/" "node_modules/"

    # Add license and copyright to a file
    fosslight_prechecker add -p test.py -l "GPL-3.0-only" -c "2019-2021 LG Electronics Inc."

    # Add license, copyright, and download location
    fosslight_prechecker add -p src/main.py -l "Apache-2.0" -c "2023 MyCompany" -u "https://github.com/user/repo"

    # Convert sbom-info.yaml to Excel report
    fosslight_prechecker convert -p sbom-info.yaml

    # Download license text
    fosslight_prechecker download -l "MIT"
  • Pattern Matching Guide for the -e option
    • ⚠️ Always use double quotes ("") when entering values.
      • Example) fosslight_prechecker -e "dev/" "tests/"
    • ⚠️ File names and extensions are case-sensitive, so please enter them exactly as intended.
  • (For Windows) Run using executable file
    • Download fosslight_prechecker_windows.exe from FOSSLight Prechecker - Release
    • Two methods available:
      • 1) Move the executable to the desired path and double-click to run
        • Runs only the default Lint mode
      • 2) Run via command line
        • Open β€˜cmd'
        • Run from the path where the file is located, following the β€˜How to Run by Mode and Parameters' instructions
          ex) fosslight_prechecker lint -p src/



lint mode

  • Result files 
    $ tree
.
β”œβ”€β”€ fosslight_lint_260423_1630.yaml
└── fosslight_log_pre_260423_1630.txt

1. Analyze a specific path

(venv)$ fosslight_prechecker lint -p /home/tests -o result.yaml
  • Result
         Checking copyright/license writing rules:
        Compliant: Not-OK
        Summary:
          Open Source Package File:
          - convert/sbom-info.yaml
          - add/oss-pkg-info.yaml
          - convert/oss-pkg-info.yaml
          - lint/sub1/sbom-info.yaml
          - lint/sub2/oss-pkg-info.yaml
          Detected Licenses:
          - Apache-2.0
          - GPL-3.0-only
          - MIT
          Files without license / total: 3 / 16
          Files without copyright / total: 3 / 16
        Files without license and copyright:
        - lint/fosslight_lint_260424_1022.yaml
        - lint/fosslight_log_pre_260424_1022.txt
        Files without license:
        - lint/sub1/source_missing_lic.py
        Files without copyright:
        - lint/sub2/source_missing_cop.py
        Tool Info:
          OS: Linux 5.15.0-138-generic
          Analyze path: tests
          Python version: 3
          fosslight_prechecker version: fosslight_prechecker v4.0.8

2. Analyze specific files

(venv)$ fosslight_prechecker lint -p "src/file1.py,src/file2.py"
  • Result
          [FOSSLIGHT_PRECHECKER] Tool Info : fosslight_prechecker v4.0.8
      [FOSSLIGHT_PRECHECKER] # src/fosslight_prechecker/cli.py
      [FOSSLIGHT_PRECHECKER] * License: GPL-3.0-only
      [FOSSLIGHT_PRECHECKER] * Copyright: Copyright (c) 2021 LG Electronics Inc.
      Copyright to add(used in only 'add' mode)", type=str, dest='copyright', default="")

      [FOSSLIGHT_PRECHECKER] # src/fosslight_prechecker/_result.py
      [FOSSLIGHT_PRECHECKER] * License: GPL-3.0-only
      [FOSSLIGHT_PRECHECKER] * Copyright: Copyright (c) 2022 LG Electronics Inc.
      Copyright and License Writing Rules in Source Code. : " + RULE_LINK

      Checking copyright/license writing rules:
        Compliant: OK
        Summary:
          Open Source Package File: N/A
          Detected Licenses: N/A
          Files without license / total: 0 / 2
          Files without copyright / total: 0 / 2
        Files without license and copyright: N/A
        Files without license: N/A
        Files without copyright: N/A
        Tool Info:
          OS: Linux 5.15.0-138-generic
          Analyze path:
          - src/fosslight_prechecker/cli.py
          - src/fosslight_prechecker/_result.py
          Python version: 3
          fosslight_prechecker version: fosslight_prechecker v4.0.8
  • Contents of result

    Depending on the format, the resulting output may differ. (Default format: yaml)

    • Compliant: Whether the lint result is compliant (OK or Not OK)
    • Files without copyright: List of files without copyright
    • Files without license: List of files without a license
    • Files without license and copyright: List of files missing both copyright and license
    • Summary
      • Detected Licenses: Licenses detected in the source code
      • Files without copyright / total: Number of files without copyright / Total number of files
      • Files without license / total: Number of files without license / Total number of files
      • Open Source Package File: List of sbom-info*.yaml or oss-pkg-info*.yaml files
      • Tool Info
        • Analysis path: Path that was analyzed
        • OS: OS version on which FOSSLight Prechecker was executed
        • Python version: Python version on which FOSSLight Prechecker was executed
        • fosslight_prechecker version: FOSSLight Prechecker version
    • Items excluded when calculating the number of files
      • Hidden files and files within hidden directories
      • Binary files
      • Files with specific extensions (jar, png, exe, so, a, dll, jpeg, jpg, ttf, lib, ttc, pfb, pfm, otf, afm, dfont, json)
      • Files within venv and node_modules directories
      • Files defined in .gitignore
      • Untracked files based on git repo
      • User-defined excluded paths (-e option)
      • Paths with exclude set to True in sbom-info.yaml or oss-pkg-info.yaml



add mode

If a file does not have existing copyright or license information, the missing information will be added to each file.

(venv)$ fosslight_prechecker add -p tests/add -c "2025-2026 LG Electronics Inc." -l "GPL-3.0-only" -u "https://www.testurl.com"
  • Result 
      [FOSSLIGHT_PRECHECKER] 
  # File list that have both license and copyright : 2 / 5
  # test_both_have_1.py
  * License: GPL-3.0-only
  * Copyright: SPDX-FileCopyrightText: Copyright 2019-2021 LG Electronics Inc.

  # test_both_have_2.py
  * License: GPL-3.0-only
  * Copyright: SPDX-FileCopyrightText: Copyright (c) 2011 LG Electronics Inc.

  # Missing license File(s)
    * oss-pkg-info.yaml
    * test_no_license.py
    * Your input license : GPL-3.0-only
  Successfully changed header of tests/add/oss-pkg-info.yaml
  Successfully changed header of tests/add/test_no_license.py

  # Missing Copyright File(s) 
    * test_no_copyright.py
    * Your input Copyright : Copyright 2025-2026 LG Electronics Inc.
  Successfully changed header of tests/add/test_no_copyright.py

  # Adding Download Location into your files
    * Your input DownloadLocation : https://www.testurl.com
  Successfully changed header of tests/add/test_both_have_1.py
  Successfully changed header of tests/add/test_both_have_2.py
  Successfully changed header of tests/add/test_no_copyright.py
  Successfully changed header of tests/add/oss-pkg-info.yaml
  Successfully changed header of tests/add/test_no_license.py
  OS: Linux 5.15.0-138-generic
  Path to analyze: tests/add
  Python version: 3
  Tool Info: fosslight_prechecker v4.0.8

(venv)$ fosslight_prechecker add -p "tests/add/test_both_have_1.py,tests/add/test_both_have_2.py,tests/add/test_no_copyright.py,tests/add/test_no_license.py" -c "2025-2026 LG Electronics Inc." -l "GPL-3.0-only" -u "https://www.testurl.com"
  • Result 
      # SPDX-FileCopyrightText: Copyright 2025-2026 LG Electronics Inc.
  #
  # SPDX-License-Identifier: GPL-3.0-only
  #
  # SPDX-PackageDownloadLocation: https://www.testurl.com

  import os
  from fosslight_util.set_log import init_log



convert mode

  • Result files 
    $ tree
β”œβ”€β”€ fosslight_report_pre_260424_1010.xlsx
└── fosslight_log_pre_260424_1010.txt

Convert OSS information in YAML format to Fosslight Report

  • Analyzes sbom-info.yaml or oss-pkg-info.yaml files in the specified path and converts them to an Excel report in Fosslight_Report.xlsx format.
  • If there are multiple YAML files, each file is converted to a separate individual sheet. 
    $ fosslight_prechecker convert -p tests/
  • Result
    • oss-pkg-info.yaml
      When writing a path in the yaml file, if it starts with a special character ({, }, [, ], &, *, #, ?, , -, <, >, =, !, %, @), use double quotation marks (""). 
      glibc:
- version: '2.3'
  source name or path:
  - tests/b.c
  - tests/a.c
  license:
  - GPL-3.0
  - LGPL-2.1
  download location: https://github.com/fsfe/glibc
dbus:
- version: '1.3'
  source name or path:
  - tests/src/*
  license:
  - GPL-2.0
  download location: https://github.com/fsfe/dbus
  copyright text: 'Copyright (c) 2020 Test Copyright (c) 2020 Sample'
reuse-tool:
- version: ''
  source name or path:
  - tests/
  license:
  - MIT
  download location: https://github.com/fsfe/reuse
  homepage: http://google.com
  copyright text: Copyright (c) 2020 Test
build-tool:
- version: ''
  source name or path:
  - tests/
  license:
  - Apache-2.0
  download location: http://gihub.com/bazel
  exclude: true
    • fosslight_report.xlsx

      FOSSLight Report



download mode

  1. Download licenses written in sbom-info.yaml as text files 
    (venv)$ fosslight_prechecker download -p tests/
    • Result 
        Successfully downloaded tests/LICENSES/GPL-3.0-only.txt.
  Successfully downloaded tests/LICENSES/MIT.txt.
  Successfully downloaded tests/LICENSES/LGPL-2.1-only.txt.
  Successfully downloaded tests/LICENSES/GPL-2.0-only.txt.
  2. Example of creating a representative license file 
    (venv)$ fosslight_prechecker download -p tests/ -l "Apache-2.0"
    • Result 
       Successfully downloaded tests/temp_lic/LICENSES/Apache-2.0.txt.
 # Created Representative License File (tests/temp_lic/LICENSES/Apache-2.0.txt -> LICENSE)