Friendly Filenames

A comprehensive bash script to normalize file names with multiple case style options, smart defaults, and extensive commenting for future developers.

Features

• 8 Case Styles Available: snake_case, kebab-case, camelCase, PascalCase, UPPER_SNAKE, flatcase, UPPERCASE, slug-case
• Smart Defaults: Press ENTER to accept sensible defaults for quick operation
• Intelligent Renaming: Only renames files that need it - properly named files are left unchanged
• Always Lowercase Extensions: File extensions are always normalized to lowercase regardless of case style
• Target Directory Control: Choose your output directory with default handling for existing directories
• Comprehensive Comments: Extensively documented code for future developers
• Recursive Processing: Handles files in subdirectories (flattened to output directory)
• Safe Operation: Copies files to a new directory, leaving originals untouched
• Git Integration: Output directory automatically ignored via .gitignore

Installation

No installation required. Simply ensure you have bash available (standard on Linux/macOS).

Tested on: Ubuntu 22.04

Usage

Quick Start (Using Defaults)

For fastest operation, simply run the script and press ENTER for all prompts to use defaults:

./normalize_filenames.sh

Default settings:

• Source directory: ./files
• Target directory: ./files-renamed
• Case style: snake_case
• Existing directory handling: Delete and recreate

Custom Configuration

Follow the interactive prompts to customize:

1. Source Directory: Where your files are located (default: ./files)
2. Target Directory: Where normalized files will be saved (default: ./files-renamed)
3. Existing Directory Handling:
   • Option 1 (default): Delete existing target directory and start fresh
   • Option 2: Preserve existing directory and add files to it
4. Case Style Selection:
   • 1. snake_case (my_file_name.txt) - DEFAULT
   • 2. kebab-case (my-file-name.txt)
   • 3. slug-case (my-file-name.txt) - same as kebab
   • 4. camelCase (myFileName.txt)
   • 5. PascalCase (MyFileName.txt)
   • 6. UPPER_SNAKE (MY_FILE_NAME.txt)
   • 7. flatcase (myfilename.txt)
   • 8. UPPERCASE (MYFILENAME.txt)

Examples

Input Files

• My Document.txt
• Photo 2024-05-30.jpg
• UPPERCASE FILE.DOC
• Project_Final-Version (2).pdf
• Budget Analysis FINAL.XLS

Output by Case Style

snake_case (default):

• my_document.txt
• photo_2024_05_30.jpg
• uppercase_file.doc
• project_final_version_2.pdf
• budget_analysis_final.xls

camelCase:

• myDocument.txt
• photo20240530.jpg
• uppercaseFile.doc
• projectFinalVersion2.pdf
• budgetAnalysisFinal.xls

PascalCase:

• MyDocument.txt
• Photo20240530.jpg
• UppercaseFile.doc
• ProjectFinalVersion2.pdf
• BudgetAnalysisFinal.xls

UPPER_SNAKE:

• MY_DOCUMENT.txt
• PHOTO_2024_05_30.jpg
• UPPERCASE_FILE.doc
• PROJECT_FINAL_VERSION_2.pdf
• BUDGET_ANALYSIS_FINAL.xls

Sample Files

The ./files directory contains sample files with various naming issues for testing purposes. Delete these sample files before adding your own files to rename.

To clear sample files:

rm -rf ./files/*

Important Rules

File Extensions

• Always lowercase: Extensions are normalized to lowercase regardless of case style
• Examples: .TXT → .txt, .PDF → .pdf, .JPG → .jpg

Processing Logic

• Smart detection: Files already properly named are copied as-is
• Safe operation: Original files are never modified, only copied
• Recursive flattening: Subdirectory files are copied to the target directory root

Case Style Rules

Each case style has specific character and formatting requirements:

• snake_case / UPPER_SNAKE: Letters, numbers, underscores only
• kebab-case / slug-case: Letters, numbers, hyphens only
• camelCase: Starts lowercase, mixed case, no separators
• PascalCase: Starts uppercase, mixed case, no separators
• flatcase: All lowercase, no separators
• UPPERCASE: All uppercase, no separators

Developer Notes

The script is extensively commented for future developers:

• Function documentation with parameters and return values
• Section headers explaining each part of the script
• Inline comments for complex operations
• Clear variable naming and logical flow

Git Integration

• Output directory (files-renamed/) is automatically ignored via .gitignore
• Comprehensive .gitignore includes Node.js, OS-specific, and development tool files