Flatten Directory Structure

A Bash script that flattens nested directory structures by moving all files from subdirectories to the root level. Automatically handles filename conflicts and cleans up empty directories.

Features

Recursive file moving: Finds all files in nested subdirectories
Conflict resolution: Automatically renames duplicates with _1, _2, etc.
Extension preservation: Maintains file extensions when renaming
Empty directory cleanup: Removes empty subdirectories after moving
Safe operations: Uses absolute paths to prevent errors

Use Case

Perfect for cleaning up messy download folders, organizing extracted archives, or consolidating scattered files:

# Flatten a messy downloads folder
./flatten-dirs.sh ~/Downloads/project

# Consolidate extracted archive
./flatten-dirs.sh ./extracted_files

# Clean up nested photo directories
./flatten-dirs.sh ~/Pictures/vacation

Before & After Example

Before:

my-folder/
├── file1.txt
├── subdir1/
│   ├── file2.txt
│   └── file1.txt  (conflict!)
└── subdir2/
    └── nested/
        └── file3.jpg

After:

my-folder/
├── file1.txt
├── file1_1.txt  (renamed to avoid conflict)
├── file2.txt
└── file3.jpg

How It Works

Validation: Checks if directory exists
Absolute path: Converts input to absolute path
File discovery: Finds all files at depth ≥2
Conflict detection: Checks for existing files with same name
Smart renaming: Adds _N suffix before extension if conflict
Moving: Relocates files to root directory
Cleanup: Removes empty subdirectories

Usage

# Basic usage
./flatten-dirs.sh <directory>

# Example
./flatten-dirs.sh ~/Downloads/nested_folder

Output Example

Moved: /path/to/folder/subdir/file.txt -> /path/to/folder/file.txt
Moved: /path/to/folder/another/file.txt -> /path/to/folder/file_1.txt
Moved: /path/to/folder/deep/nested/image.jpg -> /path/to/folder/image.jpg
Directory structure flattened

Source Code

flatten-dirs.sh

#!/bin/bash

# Check if directory is provided
if [ $# -ne 1 ]; then
    echo "Usage: $0 <directory>"
    exit 1
fi

# Check if directory exists
if [ ! -d "$1" ]; then
    echo "Error: Directory '$1' does not exist"
    exit 1
fi

# Convert to absolute path
target_dir=$(realpath "$1")

# Find all files in subdirectories and move them to root
find "$target_dir" -type f -mindepth 2 | while read -r file; do
    filename=$(basename "$file")
    dest="$target_dir/$filename"

    # Handle filename conflicts
    counter=1
    while [ -f "$dest" ]; do
        base="${filename%.*}"
        ext="${filename##*.}"
        if [ "$base" = "$ext" ]; then
            # File has no extension
            dest="$target_dir/${base}_${counter}"
        else
            # File has extension
            dest="$target_dir/${base}_${counter}.${ext}"
        fi
        ((counter++))
    done

    # Move the file
    mv "$file" "$dest"
    echo "Moved: $file -> $dest"
done

# Remove empty directories
find "$target_dir" -type d -mindepth 1 -empty -delete

echo "Directory structure flattened"

Safety Notes

⚠️ This operation modifies your filesystem
🔒 Consider making a backup before running
📝 Review the output to see which files were moved
🗑️ Empty directories are permanently deleted