FOP - Filter Orderer and Preener (Rust Edition)

A Rust port of the EasyList FOP tool for sorting and cleaning ad-blocking filter lists.

Features

- Filter sorting: Alphabetically sorts blocking rules and element hiding rules
- Domain combining: Merges rules with identical selectors/patterns but different domains
- Option normalization: Converts uBO-specific options to standard ABP format (can be disabled)
- Wildcard cleanup: Removes unnecessary wildcards from filters
- Validation: Removes invalid/overly-broad rules (TLD-only, too short, etc.)
- Git integration: Commit changes directly to repositories (can be disabled)
- easylist_adservers.txt validation: Ensures rules start with | or /
- :has-text() merging: Combines rules with same base selector into single regex
- Parallel processing: Uses all CPU cores for faster processing via Rayon

Extended Syntax Support

FOP preserves extended filter syntax from various adblockers:

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- Scriptlet injection: ##+js(...), ##^script:has-text(...)
- Procedural cosmetics: :has-text(), :has(), :upward(), :remove(), :style(), :matches-css(), :xpath(), :remove-attr(), :remove-class(), :watch-attr(), :min-text-length(), :others()
- Network options: redirect=, redirect-rule=, removeparam=, denyallow=, replace=, header=, permissions=, to=, from=, method=
- Regex domain rules: /regex/##+js(...)

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- Scriptlet injection: #%#//scriptlet(...)
- CSS injection: #$#body { ... }
- Exceptions: #@%#, #@$#

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- Extended selectors: :-abp-has(), :-abp-contains(), :-abp-properties()
- Action syntax: {remove: true;}, {height:...}, {display:...}
- Snippets: #$#hide-if-contains, #$#simulate-mouse-event

Speed Comparison (FOP.py vs FOP Rust)

Installation

``bash
npm install -g fop-cli
`

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Requires Rust 1.80+ (https://rustup.rs)

`bash
cd fop-rs
cargo build --release
cp target/release/fop /usr/local/bin/ # or add to PATH
`

Usage

`bash


Sort filters in current directory (with commit prompt)

fop

Sort filters in a specific directory

fop /path/to/easylist

Sort without commit prompt (like FOP-nocommit.py)

fop --no-commit /path/to/easylist
fop -n .

Sort without converting uBO options to ABP format

fop --no-ubo-convert /path/to/ublock-filters

Sort multiple directories

fop -n ~/easylist ~/easyprivacy ~/fanboy-addon
`

Command Line Options

| Option | Description |
|--------|-------------|
| -n, --no-commit | Just sort files, skip Git commit prompts |
| --just-sort | Alias for --no-commit |
| --no-ubo-convert | Skip uBO to ABP option conversion (keep xhr, 3p, 1p, etc.) |
| --no-msg-check | Skip commit message format validation (M:/A:/P:) |
| --disable-ignored | Disable hardcoded ignored files and folders for testing |
| --no-sort | Don't sort rules, just combine |
| --alt-sort | More correct sorting method |
| --localhost | Sort hosts file entries (0.0.0.0/127.0.0.1 domain) |
| --no-color | Disable colored output |
| --no-large-warning | Disable large change warning prompt |
| --backup | Create .backup files before modifying |
| --keep-empty-lines | Keep empty lines in output |
| --ignore-dot-domains | Don't skip rules without dot in domain |
| --ignorefiles= | Additional files to ignore (comma-separated, partial names) |
| --ignoredirs= | Additional directories to ignore (comma-separated, partial names) |
| --ignore-all-but= | Only process these files, ignore all others (comma-separated) |
| --file-extensions= | File extensions to process (default: .txt) |
| --comments= | Comment line prefixes (default: !) |
| --disable-domain-limit= | Files to skip short domain check (comma-separated) |
| --warning-output= | Output warnings to file instead of stderr |
| --git-message= | Git commit message (skip interactive prompt) |
| --history= | Predefined commit messages for arrow key selection (comma-separated) |
| --create-pr[=TITLE] | Create PR branch instead of committing to current branch |
| --git-pr-branch=NAME | Base branch for PR (default: auto-detect main/master) |
| --pr-show-changes | Include rule changes (combines, merges, typos) in PR body |
| --fix-typos | Fix cosmetic rule typos in all files during sort |
| --fix-typos-on-add | Check cosmetic rule typos in git additions before commit |
| --auto-fix | Auto-fix typos without prompting (use with --fix-typos-on-add) |
| --only-sort-changed | Only process files changed according to git |
| --check-banned-list=FILE | Check for banned domains in git additions |
| --auto-banned-remove | Auto-remove banned domains and commit |
| --ci | CI mode - exit with error code on failures (banned domains) |
| --rebase-on-fail | Auto rebase and retry push if it fails |
| --ignore-config | Ignore .fopconfig file, use only CLI args |
| --output | Output changed files with --changed suffix (no overwrite) |
| --check-file=FILE | Process a single file |
| --output-diff=FILE | Output changes as diff (no files modified) |
| --quiet | Limit console output, less verbose |
| --add-checksum=FILES | Add/update checksum for specific files (comma-separated) |
| --add-timestamp | Update timestamp in file header (Last Modified/Last Updated) |
| --config-file= | Custom config file path |
| --show-config | Show applied configuration and exit |
| --git-binary= | Path to git binary (default: git in PATH) |
| -h, --help | Show help message |
| -V, --version | Show version number |

Configuration File

Create .fopconfig in your working directory or home directory:

`ini


Skip commit prompt

no-commit = false

Skip uBO to ABP option conversion

no-ubo-convert = false

Skip commit message format validation

no-msg-check = false

Skip sorting (only tidy and combine rules)

no-sort = false

Alternative sorting method

alt-sort = false

Sort hosts file entries

localhost = false

Disable colored output

no-color = false

Disable large change warning prompt

no-large-warning = false

Create .backup files before modifying

backup = false

Keep empty lines in output

keep-empty-lines = false

Don't skip rules without dot in domain

ignore-dot-domains = false

Comment line prefixes

comments = !

Files to skip short domain check

disable-domain-limit =

Output warnings to file

warning-output =

Additional files to ignore

ignorefiles = .json,.backup,.bak,.swp,.gz

Additional directories to ignore

ignoredirs =

File extensions to process

file-extensions = txt

Create PR branch instead of committing

create-pr =

Include rule changes in PR body

pr-show-changes = false

Base branch for PR (default: auto-detect)

git-pr-branch =

Fix cosmetic typos during sort

fix-typos = false

Check typos in git additions

fix-typos-on-add = false

Auto-fix without prompting

auto-fix = false

Only sort git-changed files (skip unchanged)

only-sort-changed = false

Path to banned domain list file

check-banned-list =

Auto-remove banned domains and commit

auto-banned-remove = false

CI mode - exit with error code on failures

ci = false

Auto rebase and retry if push fails

rebase-on-fail = false

Suppress most output (for CI)

quiet = false

Users allowed to push directly when create-pr is enabled (comma-separated, case-insensitive)

direct-push-users =

Predefined commit messages for arrow key selection (comma-separated)

Use up/down arrows at commit prompt to cycle through these

history = A: ,P: ,M: Update,M: Cleanup,M: Sort,M: Adjust
`

Command line arguments override config file settings.

Platform Support

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| Platform | Binary | Optimization | Compatible Devices |
|----------|--------|--------------|-------------------|
| Linux | | | |
| x86_64 | linux-x86_64 | Baseline | All 64-bit Intel/AMD |
| x86_64 | linux-x86_64-v3 | AVX2 | Intel Haswell+ / AMD Excavator+ (~2015+) |
| x86 | linux-x86_32 | Baseline | 32-bit systems, older hardware |
| ARM64 | linux-arm64 | Baseline | Raspberry Pi 3/4/5, Orange Pi 3/4/5, all ARM64 |
| ARM64 | linux-arm64-n1 | Neoverse N1 | Pi 5, Orange Pi 5, AWS Graviton2+, Ampere Altra |
| RISC-V | linux-riscv64 | Baseline | SiFive, StarFive VisionFive 2, Milk-V |
| macOS | | | |
| Intel | macos-x86_64 | Baseline | All Intel Macs |
| Apple Silicon | macos-arm64 | Apple M1 | M1, M2, M3, M4, M5 Macs |
| Windows | | | |
| x86_64 | windows-x86_64.exe | Baseline | All 64-bit Windows |
| x86_64 | windows-x86_64-v3.exe | AVX2 | Intel Haswell+ / AMD Excavator+ (~2015+) |
| x86 | windows-x86_32.exe | Baseline | 32-bit Windows |
| ARM64 | windows-arm64-v2.exe | Cortex-A78 | Surface Pro X, Snapdragon laptops |

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Linux/Windows x86_64:
- Use -v3 for CPUs from ~2015+ (Haswell, Ryzen) - ~10-20% faster due to AVX2
- Use baseline if unsure or on older CPUs

Linux ARM64 (Raspberry Pi / Orange Pi):
- Use linux-arm64 for Pi 3, Pi 4, Orange Pi 3/4, or if unsure
- Use linux-arm64-n1 for Pi 5, Orange Pi 5, AWS Graviton2+ (~10-20% faster)

npm install downloads baseline binaries for maximum compatibility. Optimized versions are available from GitHub Releases.

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| Binary | Target | RUSTFLAGS |
|--------|--------|-----------|
| linux-x86_64 | Native | - |
| linux-x86_64-v3 | Native | -C target-cpu=x86-64-v3 |
| linux-x86_32 | i686-unknown-linux-gnu | - |
| linux-arm64 | aarch64-unknown-linux-gnu | - |
| linux-arm64-n1 | aarch64-unknown-linux-gnu | -C target-cpu=neoverse-n1 |
| linux-riscv64 | riscv64gc-unknown-linux-gnu | - |
| macos-x86_64 | x86_64-apple-darwin | - |
| macos-arm64 | aarch64-apple-darwin | -C target-cpu=apple-m1 |
| windows-x86_64.exe | x86_64-pc-windows-gnu | - |
| windows-x86_64-v3.exe | x86_64-pc-windows-gnu | -C target-cpu=x86-64-v3 |
| windows-x86_32.exe | i686-pc-windows-gnu | - |
| windows-arm64-v2.exe | aarch64-pc-windows-msvc | -C target-cpu=cortex-a78 |


Unsupported platform?
FOP.rs builds from source on any platform with Rust 1.80+:
`bash
cargo build --release
`

Migrating from Python FOP

This Rust version is a drop-in replacement for both FOP.py and FOP-nocommit.py:

| Python | Rust Equivalent |
|--------|-----------------|
| python3 FOP.py | fop |
| python3 FOP-nocommit.py | fop --no-commit or fop -n |

Performance

The Rust version is significantly faster than Python FOP due to:
- Compiled native code
- Parallel file processing with Rayon
- Optimized regex handling
- Efficient memory management

Windows PowerShell Note

If you see UnauthorizedAccess or PSSecurityException when running fop in PowerShell, run this once to fix permanently:
`powershell
Set-ExecutionPolicy RemoteSigned -Scope CurrentUser
``

Alternatively, use Git Bash, MINGW64, or WSL.

License

GPL-3.0 (same as original Python FOP)

Credits

- Original Python FOP by Michael (EasyList project)
- Rust port maintains feature parity with Python version 3.9