Blinter

Linux macOS Windows

Blinter is a linter for Windows batch files (.bat and .cmd). It provides static analysis to identify syntax errors, security vulnerabilities, performance issues and style problems. Blinter helps you write safer, more reliable and maintainable batch scripts on Linux, macOS or Windows.

✅ Configurable Options - Configurable rules, --verbose/--quiet logging, robust error handling
✅ Unicode Support - Support for international characters and filenames
✅ Performance Optimized - Handles large batch files efficiently

Features ✨

🔍 Rule Categories

Built-in Rules -- the registry currently ships 193 rules across 5 severity levels (see blinter.rules.registry.RULE_COUNT)
Error Level (E001-E999): Critical syntax errors that prevent execution
Warning Level (W001-W999): Potential runtime issues and bad practices
Style Level (S001-S999): Code formatting and readability improvements
Security Level (SEC001+): Security vulnerabilities and dangerous operations
Performance Level (P001-P999): Optimization opportunities and efficiency improvements

📖 For complete rule descriptions with examples and implementation details, see Batch-File-Linter-Requirements.md

📋 Output Format

Rule Codes: Each issue has a unique identifier (e.g., E002, W005, SEC003)
Clear Explanations: Detailed descriptions of why each issue matters
Actionable Recommendations: Specific guidance on how to fix problems
Line-by-Line Analysis: Precise location of every issue
Context Information: Additional details about detected problems

🚀 Advanced Analysis

Static Code Analysis: Detects unreachable code and logic errors
Variable Expansion: Validates percent-tilde syntax (%~n1), string operations, and SET /A arithmetic
Command-Specific Validation: FOR loop variations, IF statement best practices, deprecated command detection
Variable Tracking: Identifies undefined variables and unsafe usage patterns
Security Scanning: Path traversal attacks, command injection risks, unsafe temp file creation
Performance Optimization: DIR flag optimization, unnecessary output detection, string operation efficiency
Cross-Platform Batch Compatibility: Warns about Windows version issues and deprecated commands in batch scripts
Large File Handling: Efficiently processes large batch files, with a warning when a file exceeds 10MB and a hard reject above 50MB
Encoding Detection: Automatic detection via charset-normalizer, with nine built-in fallbacks (UTF-8, UTF-8 BOM, UTF-16, UTF-32, Latin-1, ASCII, CP437, CP850, CP1252)
Escaping Techniques: Validates caret escape sequences, multilevel escaping, and continuation characters
FOR Command Analysis: Checks for usebackq, proper tokenizing, delimiters, and skip options
Process Management Best Practices: Timeout command usage, process verification, and restart patterns
Security Patterns: User input validation, temporary file security, and self-modification detection

Installation 🛠️

🚀 Quick Start (Recommended)

Option 1: Install via pip

pip install Blinter

Option 2: Install via uv

uv tool install Blinter

Run without installing:

uvx blinter

Option 3: Standalone executable

If you prefer a standalone .exe over pip or uv, use the one-line installer via cmd. Check your architecture with echo %PROCESSOR_ARCHITECTURE%, or in Settings > System > About. ARM64 means use the ARM64 line. Anything else means use the x64 line. Running the installer with no argument downloads nothing.

x64:

curl -fL --proto =https https://raw.githubusercontent.com/BatchLang/Blinter/refs/heads/main/scripts/install_blinter.cmd -o install_blinter.cmd && (call install_blinter.cmd x64 || cd .) && del install_blinter.cmd

ARM64:

curl -fL --proto =https https://raw.githubusercontent.com/BatchLang/Blinter/refs/heads/main/scripts/install_blinter.cmd -o install_blinter.cmd && (call install_blinter.cmd arm64 || cd .) && del install_blinter.cmd

This installs the latest blinter.exe for the architecture you named to %LOCALAPPDATA%\Programs\Blinter\bin, adds it to your user PATH, and handles updates automatically. On ARM64, x64 still installs and runs through emulation; arm64 is the native build. arm64 is refused on a non-ARM64 PC. Restart your terminal or IDE after installation for PATH changes to take effect.

Manual zip download (fallback):

Download Blinter-v1.x.x-x64.zip for x64 Windows, or Blinter-v1.x.x-arm64.zip for a native ARM64 executable, from GitHub Releases
Extract the archive. The executable is Blinter-v1.x.x-x64\blinter.exe or Blinter-v1.x.x-arm64\blinter.exe, matching the zip name
The one-line installer above is preferred; it keeps blinter on your PATH without manual setup.
⚠️ Note: Some antivirus software may flag the standalone executable as a false positive. The executable is completely safe (all source code is open for inspection). If a scanner flags it, use pip installation.

Uninstall

Standalone executable (one-line un-installer) via cmd. This removes whichever build is installed, x64 or ARM64:

curl -fL --proto =https https://raw.githubusercontent.com/BatchLang/Blinter/refs/heads/main/scripts/uninstall_blinter.cmd -o uninstall_blinter.cmd && (call uninstall_blinter.cmd || cd .) && del uninstall_blinter.cmd

pip installation:

pip uninstall Blinter

uv installation:

uv tool uninstall Blinter

Prerequisites

Python 3.11-3.15 (for the pip/uv install)
Windows 64-bit (x64 or ARM64) (for the standalone executable)

Usage 📟

Basic Usage

If installed via pip or uv:

# Analyze a single batch file
blinter script.bat
# or
python -m blinter script.bat

# Analyze all batch files in a directory (recursive)
python -m blinter /path/to/batch/files

# Analyze batch files in directory only (non-recursive)
python -m blinter /path/to/batch/files --no-recursive

# Analyze with summary
python -m blinter script.bat --summary

# Analyze script and scripts it calls with shared variable context
python -m blinter script.bat --follow-calls

# Analyze with custom maximum line length
python -m blinter script.bat --max-line-length 120

# Create configuration file
python -m blinter --create-config

# Ignore configuration file
python -m blinter script.bat --no-config

# Get help
python -m blinter --help

# Get version
python -m blinter --version

If using standalone executable (installer or manual download):

# After the one-line installer, use blinter on PATH.
# Manual zip: run Blinter-v1.x.x-x64\blinter.exe or Blinter-v1.x.x-arm64\blinter.exe,
# or add that folder to PATH.

# Analyze a single batch file
blinter script.bat

# Analyze all batch files in a directory (recursive)
blinter /path/to/batch/files

# Analyze batch files in directory only (non-recursive)
blinter /path/to/batch/files --no-recursive

# Analyze with summary
blinter script.bat --summary

# Analyze script and scripts it calls with shared variable context
blinter script.bat --follow-calls

# Analyze with custom maximum line length
blinter script.bat --max-line-length 120

# Get help
blinter --help

# Get version
blinter --version

# Create configuration file
blinter --create-config

# Ignore configuration file
blinter script.bat --no-config

If you installed both

pip, uv, and the standalone installer can all put blinter on PATH. The installer appends %LOCALAPPDATA%\Programs\Blinter\bin and does not move that folder ahead of an existing copy. When another blinter is earlier on PATH, the installer prints that path and says the standalone folder will not win. blinter --version prints standalone exe or Python 3.x plus the package directory so you can see which copy is running. The uninstaller stops only %LOCALAPPDATA%\Programs\Blinter\bin\blinter.exe.

Command Line Options

<path>: Path to a batch file (.bat or .cmd) OR directory containing batch files
--summary: Display summary statistics of issues found
--max-line-length <n>: Set maximum line length for S011 and S020 rules (default: 100)
--no-recursive: When processing directories, only analyze files in the specified directory (not subdirectories)
--follow-calls: Automatically analyze scripts called by CALL statements and merge their variable context. When enabled, variables defined in called scripts (including transitively called scripts within depth and file limits) are recognized as "defined" in the calling script (position-aware: only after the CALL statement). This eliminates false positive undefined variable errors for configuration scripts. Each script's CALL list is walked once, including when scripts call each other in a cycle
--fail-on <level>: Exit 1 when a finding is at or above this severity. Levels, from least to most severe: style, performance, warning, security, error. none never fails because of findings. The default is security, so Error and Security findings are fatal. This flag overrides fail_on in blinter.ini
--baseline <path>: Accept findings recorded in a JSON file. A new finding still follows --fail-on. A recorded finding that no longer matches exits 1
--update-baseline: Rewrite the --baseline file from the current findings. Requires --baseline. Entries for files that were not part of this run are kept
--config <path>: Load settings from a custom configuration file instead of blinter.ini in the current directory
--no-config: Don't use configuration file (blinter.ini) even if it exists
--create-config: Create a default blinter.ini configuration file and exit
--create-config --force: Overwrite an existing blinter.ini when creating the default configuration
--output <path>: Write a structured report to the given file path. The file is JSON unless --format sarif is also set. Human-readable output stays on stdout unless --format is set
--format json: Suppress human-readable stdout and emit JSON (to stdout, or only to --output when both flags are used)
--format sarif: Suppress human-readable stdout and emit SARIF 2.1.0 (to stdout, or only to --output when both flags are used). Paths are relative to the working directory, so run Blinter from the repository root when uploading to GitHub
--verbose: Show detailed debug logging on stderr (DEBUG level)
--quiet: Suppress non-error logging output (ERROR level only)
--help: Show help menu and rule categories
--version: Display version information

Note: Command line options override configuration file settings. Blinter automatically looks for blinter.ini in the current directory.

Configuration File Options 📝

Section	Setting	Description	Default
`[general]`	`recursive`	Search subdirectories when analyzing folders	`true`
`[general]`	`show_summary`	Display summary statistics after analysis	`false`
`[general]`	`max_line_length`	Maximum line length for S011 and S020 rules	`100`
`[general]`	`max_scan_files`	Maximum batch files to scan in a directory	`1000`
`[general]`	`follow_calls`	Analyze scripts called by CALL statements with shared variable context	`false`
`[general]`	`min_severity`	Minimum severity level to report	None (all)
`[general]`	`fail_on`	Lowest severity that makes the process exit 1 (`style`, `performance`, `warning`, `security`, `error`, or `none`)	`security`
`[rules]`	`enabled_rules`	Comma-separated list of rules to enable exclusively	None (all enabled)
`[rules]`	`disabled_rules`	Comma-separated list of rules to disable	None

Configuration notes:

When both enabled_rules and disabled_rules are set, a rule must appear in enabled_rules to run; disabled_rules then removes matches from that allowlist.
max_line_length in blinter.ini controls style rules S011/S020 (default 100). A line longer than 10,000 characters is reported as E048 and skipped so the rest of the file is still linted. A line longer than 1,000,000 characters is rejected before linting.

Command Line Override

Command line options always override configuration file settings:

# Use config file settings
python -m blinter myscript.bat

# Override config to show summary
python -m blinter myscript.bat --summary

# Analyze script and scripts it calls with shared variable context
python -m blinter myscript.bat --follow-calls

# Override config with custom line length
python -m blinter myscript.bat --max-line-length 100

# Ignore config file completely
python -m blinter myscript.bat --no-config

# Write JSON report to a file (human-readable output unchanged)
python -m blinter myscript.bat --output report.json

# Machine-readable JSON on stdout only
python -m blinter myscript.bat --format json

# JSON file only, no human-readable stdout
python -m blinter project/scripts --output results.json --format json

# SARIF 2.1.0 on stdout (GitHub Code Scanning upload)
python -m blinter myscript.bat --format sarif

# SARIF file only, no human-readable stdout
python -m blinter project/scripts --output results.sarif --format sarif

🔕 Inline Suppression Comments

You can suppress specific linter warnings directly in your batch files using special comments:

Suppress Next Line

REM LINT:IGNORE E009
ECHO '' .... Represents a " character

Suppress Current Line

REM LINT:IGNORE-LINE S013

Suppress Multiple Rules

REM LINT:IGNORE E009, W011, S004
ECHO Unmatched quotes "

Suppress All Rules on Line

REM LINT:IGNORE
REM This line and the next will be ignored for all rules

Supported formats:

REM LINT:IGNORE <code> - Suppress specific rule(s) on the next line
REM LINT:IGNORE - Suppress all rules on the next line
REM LINT:IGNORE-LINE <code> - Suppress specific rule(s) on the same line
REM LINT:IGNORE-LINE - Suppress all rules on the same line
:: LINT:IGNORE <code> - Alternative comment syntax (also supported)

The directive and its rule codes match case-insensitively in ASCII only. lınt:ıgnore and ſEC008 are not a directive or a rule code, so they suppress nothing.

Use cases:

Suppress false positives that can't be fixed
Ignore intentional deviations from best practices
Handle edge cases in documentation or help text
Temporarily ignore issues during development

Baseline file

--baseline records findings a project accepts without editing the script. Each finding has its own entry, matched on the rule code, the file path relative to the baseline file, and the trimmed text of the line. Line numbers are not part of the match, so inserting a line elsewhere does not invalidate an entry. Two identical lines need two entries.

blinter scripts --baseline blinter-baseline.json
blinter scripts --baseline blinter-baseline.json --update-baseline

[
  {"code": "SEC009", "file": "scripts/update.bat", "text": "powershell -NoProfile -ExecutionPolicy Bypass ^"}
]

Paths use POSIX separators and are relative to the directory that contains the baseline file, so the same file works on Windows and on POSIX. --update-baseline rewrites the file from the current findings and keeps entries for files that were not scanned. A new finding exits 1 only when its severity is at or above --fail-on (or fail_on). A stale entry, one that no longer matches any finding in a file that was scanned, always exits 1.

The JSON report adds summary.baselined_issues and stale_baseline_entries. Text output lists stale entries. SARIF lists the new findings; a stale entry still exits 1.

🐍 Programmatic API Usage

Blinter exposes a small public API from the top-level blinter package:

from blinter import (
    BlinterConfig,
    RuleSeverity,
    lint_batch_file,
    load_config,
)

# Basic usage
issues = lint_batch_file("script.bat")
for issue in issues:
    print(f"Line {issue.line_number}: {issue.rule.name} ({issue.rule.code})")

# With custom configuration
config = BlinterConfig(
    max_line_length=80,
    disabled_rules={"S007", "S011"},
    min_severity=RuleSeverity.WARNING,
)
issues = lint_batch_file("script.bat", config=config)

# Process results
for issue in issues:
    print(f"Line {issue.line_number}: {issue.rule.name}")
    print(f"  {issue.rule.explanation}")
    print(f"  Fix: {issue.rule.recommendation}")

# Thread-safe design allows safe concurrent usage
from concurrent.futures import ThreadPoolExecutor

files = ["script1.bat", "script2.cmd", "script3.bat"]
with ThreadPoolExecutor(max_workers=4) as executor:
    results = list(executor.map(lint_batch_file, files))

🔧 Configuration Options (`BlinterConfig`)

Parameter	Type	Default	Description
`recursive`	`bool`	`True`	Search subdirectories when linting a folder
`show_summary`	`bool`	`False`	Show summary statistics in CLI output
`max_line_length`	`int`	`100`	Maximum line length for S011 and S020 rules
`max_scan_files`	`int`	`1000`	Maximum batch files to scan in a directory
`follow_calls`	`bool`	`False`	Lint scripts referenced by `CALL` statements
`scan_root`	`str` \| `None`	`None`	Root path for `--follow-calls` containment (CLI sets automatically)
`enabled_rules`	`Set[str]`	empty	If non-empty, only these rule codes run
`disabled_rules`	`Set[str]`	empty	Rule codes to skip
`min_severity`	`RuleSeverity` \| `None`	`None`	Minimum severity to report (via `blinter.ini`; no dedicated CLI flag)
`fail_on`	`RuleSeverity` \| `None`	`RuleSeverity.SECURITY`	Lowest severity that makes the CLI exit 1. `None` (`fail_on = none`) reports findings without failing

Supported File Types

.bat files (traditional batch files)
.cmd files (recommended for modern Windows)
Unicode filenames and international characters supported
Large files handled efficiently, with a warning above 10MB and a hard reject above 50MB

📁 Directory Processing

Blinter can analyze entire directories of batch files with powerful options:

Recursive Analysis: Automatically finds and processes all .bat and .cmd files in directories and subdirectories
Non-Recursive Mode: Use --no-recursive to analyze only files in the specified directory
Batch Processing: Handles multiple files efficiently with consolidated reporting
Error Resilience: Continues processing other files even if some files have encoding or permission issues
Progress Tracking: Shows detailed results for each file plus combined summary statistics

Examples:

# Pip installation:
blinter ./my-batch-scripts                 # Analyze all files recursively
blinter . --no-recursive                   # Current directory only
blinter ./scripts --summary               # With summary statistics

# Standalone executable (installer or manual zip):
blinter ./my-batch-scripts            # Analyze all files recursively
blinter . --no-recursive              # Current directory only
blinter ./scripts --summary           # With summary statistics

# Manual zip only (extract first; the folder name matches the zip):
Blinter-v1.x.x-x64\blinter.exe ./my-batch-scripts
Blinter-v1.x.x-arm64\blinter.exe ./my-batch-scripts

🔥 Integration Example

CI/CD Integration

# Example GitHub Actions workflow
- name: Lint Batch Files
  run: |
    python -c "
    from blinter import lint_batch_file
    from blinter import RuleSeverity
    import sys
    issues = lint_batch_file('deploy.bat')
    fatal = [i for i in issues if i.rule.severity in (RuleSeverity.ERROR, RuleSeverity.SECURITY)]
    if fatal:
        print(f'Found {len(fatal)} critical issues (errors or security)!')
        sys.exit(1)
    print(f'Batch file passed with {len(issues)} total issues')
    "

MegaLinter

Blinter can lint .bat and .cmd files as a MegaLinter plugin. Add the descriptor URL to PLUGINS in .mega-linter.yml.

The blinter CLI exit codes:

Code	Meaning
0	Success: no findings at or above the failure threshold, and every discovered primary file was processed
1	Lint failure: any finding at or above the failure threshold, CLI/path errors, no processable files, any skipped primary target files, or all discovered files failed to read
2	Unexpected internal error

The default threshold is Security, so Error and Security findings are fatal and Warning, Performance, and Style findings are not. --fail-on or fail_on in blinter.ini changes that threshold. none never fails because of findings.

Special thanks go out to BrainWaveCC for all the help bug hunting.

License 📄

This project is licensed under the GNU Affero General Public License v3.0 or later (AGPL-3.0-or-later) — see COPYING for details.

Icon by Acidmit · Flaticon

Metadata

Release files for blinter 1.1.47

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Source distribution for blinter 1.1.47
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Table of built distributions (wheels) for blinter 1.1.47
File	Interpreter	ABI	Platform	Reset
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Release files / blinter-1.1.47.tar.gz

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Uploaded via	`twine/7.0.0 CPython/3.12.3`

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Uploaded via	`twine/7.0.0 CPython/3.12.3`

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