Because life's too short to rename files one by one like a caveman

fnr is a blazingly fast™ file and directory renaming tool that will make you question why you ever used mv in a for loop like some kind of shell script peasant. It's like sed for filenames, but with more colors, gitignore support, and less existential dread.

Have you ever had 47 files named component_something.rs and needed to rename them all to ui_something.rs? Have you ever stared at a directory full of test_*.py files and wished they were spec_*.py instead? Have you ever wanted to batch rename files without writing a bash script that looks like it was written by a caffeinated squirrel?

This is your salvation.

cargo install fnr-tool
# Or clone this repo and `cargo build --release` like the cool kids do

# Rename all files containing "old" to "new"
fnr "old" "new"

# Preview what would happen (because trust issues)
fnr "old" "new" --dry-run

# Use specific glob patterns
fnr "component" "ui" "**/*.rs"

# Multiple glob patterns (the power move)
fnr "test" "spec" "**/*.py" "**/*.js" "!node_modules/**"

# With base directory
fnr "old" "new" "**/*.rs" --base-dir /path/to/project

# Match multiple file types at once
fnr "component" "ui" "*.{rs,ts,js}" "*.toml"

# Exclude specific directories
fnr "old" "new" "**/*" "!target/**" "!node_modules/**"

# Search from a different base directory
fnr "config" "settings" "**/*.ini" --base-dir /path/to/configs

# Control search depth
fnr "test" "spec" "**/*.py" --max-depth 3 --min-depth 1

# Use regex because you're fancy
fnr --regex "test_(.+)" "spec_$1" "**/*.py"

# Rename all your poorly named components
fnr --regex "component_(.+)" "ui_$1" "src/**/*.rs"

By default, fnr will ask you about each rename because it respects your trust issues:

./src/old_component.rs -> ./src/new_component.rs
Replace filename/dirname? [Y]es/[n]o/[a]ll/[q]uit:

Just press a single key (no Enter required, we're not animals):

• y - Yes, rename this file
• n - No, skip this one
• a - Yes to ALL remaining files (YOLO mode)
• q - Quit and pretend this never happened

--dry-run              # See what would happen without commitment
--no-interactive       # YOLO mode (renames everything without asking)
--regex                # Enable regex patterns for the power users
--type=file            # Only rename files
--type=dir             # Only rename directories
--type=both            # Rename everything (default)
--no-recursive         # Stay in current directory like a hermit
--case-sensitive       # Because "Test" ≠ "test" (obviously)
--hidden               # Include hidden files (the secret ones)
--no-color             # Remove all joy from your terminal
--no-symlink           # Don't follow symbolic links (symbolic links are just fancy lies)
--no-skip-gitignore    # Ignore .gitignore files (embrace the chaos, rename ALL the things)
--max-depth N          # Maximum directory depth (because rabbit holes have limits)
--min-depth N          # Minimum directory depth (surface-level peasants need not apply)
--base-dir PATH        # Base directory to search from (teleport your search elsewhere like a wizard)

# You have: component_button.rs, component_input.rs, component_modal.rs
# You want: ui_button.rs, ui_input.rs, ui_modal.rs
fnr "component" "ui" "**/*.rs"

# Convert test_*.py to spec_*.py because you're fancy now
fnr "test_" "spec_" "**/*.py"

# Rename across multiple file types at once
fnr "old_api" "new_api" "**/*.{rs,ts,js,py}" "**/*.toml" "!target/**"

# Convert CamelCase to snake_case (sort of)
fnr --regex "([A-Z])" "_$1" --case-sensitive "**/*.rs"

# Rename everything with "old" to "new" in the entire project
fnr "old" "new" "**/*" --no-interactive
# (Use with caution, we are not responsible for your life choices)

# Respects .gitignore by default (like a civilized human)
fnr "component" "ui" "**/*.rs"

# Chaos mode: ignore .gitignore
fnr "component" "ui" "**/*.rs" --no-skip-gitignore

• 🌈 Colorized output - Because monochrome is for printers
• ⚡ Blazingly fast - Uses all your CPU cores (probably)
• 🎯 Smart sorting - Renames files before directories to avoid chaos
• 🔍 Multiple glob patterns - "**/*.rs" "**/*.toml" "!target/**" works like magic
• 🎨 Regex support - For when you want to feel superior
• 🛡️ Safe by default - Interactive mode prevents disasters
• 🚫 Gitignore aware - Respects your .gitignore automatically
• 📁 Base directory support - Search from anywhere
• 🎛️ Depth control - --max-depth and --min-depth for precision
• ⚡ Single-key interaction - No Enter key required in interactive mode

fnr [OPTIONS] <PATTERN> [REPLACEMENT] [GLOB_PATTERNS...] [--base-dir BASE_DIR]

# Single pattern
fnr "old" "new" "**/*.rs"

# Multiple patterns
fnr "component" "ui" "**/*.rs" "**/*.ts" "**/*.js"

# With exclusions
fnr "test" "spec" "**/*.py" "!venv/**" "!__pycache__/**"

# Different base directory
fnr "config" "settings" "**/*.ini" --base-dir /path/to/configs

# Brace expansion support
fnr "old" "new" "*.{rs,toml,lock}"

• White: File paths and unchanged parts
• Yellow: The parts being changed (both old and new)
• Cyan: Action prompts
• Green/Blue: File type indicators (f for files, d for directories)

fnr respects .gitignore files by default! This means:

• No more accidentally renaming files in target/, node_modules/, or .git/
• Follows the same ignore rules as your favorite tools
• Use --no-skip-gitignore if you want to live dangerously

• One by one in Finder/Explorer: Slow death by a thousand clicks
• Bash script you found on Stack Overflow: 5 files per minute (plus debugging time)
• Copying that old script from 2019: 3 hours to remember how it works
• fnr: Instant gratification (dopamine included)

"I renamed 847 React components in 3 seconds. My manager thinks I'm a wizard now." - Anonymous Frontend Dev

"Accidentally renamed everything to 'banana' once. Still faster than doing it manually." - Senior Developer (allegedly)

"Used fnr to rename 10,000 files during my lunch break. Had time for dessert." - Performance Artist

"fnr is so fast, I renamed files that didn't even exist yet." - Time Traveler

• Multiple patterns: Uses globset for efficient simultaneous pattern matching
• Directory traversal: Uses the ignore crate for fast, gitignore-aware walking
• Smart ordering: Files are renamed before their parent directories
• Memory efficient: Streams results instead of loading everything into memory

• You've written for file in *.txt; do mv "$file" "${file%.txt}.bak"; done more than once (and felt proud about it)
• You have a folder called "New Folder (47)" and you're not even embarrassed
• You've ever used a GUI file manager to rename files one by one like some kind of masochist
• You think rename is a Perl script (it is, and that's the problem)
• You've considered learning sed just for filename manipulation (don't do it, seek help)
• You manually exclude node_modules and target directories every time like a broken record
• You've rage-quit after accidentally renaming your entire project to "untitled"
• You dream in bash loops and wake up screaming

Found a bug? Want a feature? Think the colors are wrong? Open an issue or PR!

Just remember: this tool was built by someone who got tired of renaming files manually, so the bar for "useful contribution" is pretty low.

MIT - Because sharing is caring, and lawyers are expensive.

fnr is not responsible for:

• Accidentally renaming your entire home directory to "banana"
• Making your coworkers jealous of your file organization skills
• Causing you to become overly obsessed with perfect naming conventions
• Any existential crises caused by realizing how much time you've wasted renaming files manually
• Addiction to using multiple glob patterns for everything
• Sudden urges to rename random files just because you can
• Your boss asking why you're so productive all of a sudden
• Carpal tunnel syndrome from excessive flag usage

Made with ❤️ and an unhealthy obsession with file organization and rational fear of the sed command

Remember: With great power comes great responsibility. Use --dry-run first, kids.