Automate File Organization by Type with Bash Scripts

Manually sorting files is a repetitive task that can eat into your productivity, especially if you deal with frequent downloads, reports, screenshots, or log files. With the power of Bash scripting, you can automate the organization of files based on their extensions, grouping them neatly into folders like Documents, Images, Videos, and more. This guide walks you through building and understanding a Bash script that streamlines your workspace by automating file organization.

1. The Problem: Cluttered Directories

Directories like Downloads or Desktop often become junk drawers holding mixed file types: PDFs, ZIPs, images, videos, scripts, and more. Searching through this mess slows down productivity and increases stress. Automation through Bash scripting can help by scanning through files and organizing them into well-defined folders by file type.

2. Getting Started: Setting Up the Script

We’ll start by creating a simple Bash script called organize.sh that scans a given directory (defaulting to the current one) and moves files based on their extensions. Here’s the base structure:

#!/bin/bash

target_dir=${1:-$(pwd)}

if [ ! -d "$target_dir" ]; then
    echo "Error: Directory does not exist."
    exit 1
fi

echo "Scanning directory: $target_dir"

This initializes the target directory from the first argument or defaults to the current working directory. The script exits with an error if the directory doesn’t exist.

3. Categorizing Files by Extension

We can map file extensions to folders. We’ll define an associative array (only available in bash 4.0+):

declare -A EXTENSIONS=(
    ["jpg"]="Images"
    ["png"]="Images"
    ["gif"]="Images"
    ["jpeg"]="Images"
    ["mp4"]="Videos"
    ["mkv"]="Videos"
    ["pdf"]="Documents"
    ["docx"]="Documents"
    ["xlsx"]="Documents"
    ["zip"]="Archives"
    ["tar"]="Archives"
    ["gz"]="Archives"
    ["sh"]="Scripts"
    ["py"]="Scripts"
    ["js"]="Scripts"
)

This list maps common extensions to logical directories. Feel free to extend this as per your workflow.

4. Moving Files into Folders

The heart of the script loops through all files and uses the above map to direct them:

cd "$target_dir"

for file in *; do
    if [[ -f "$file" ]]; then
        ext="${file##*.}"         # Get extension
        ext_lower=$(echo "$ext" | tr '[:upper:]' '[:lower:]')

        folder=${EXTENSIONS[$ext_lower]}

        if [[ -n "$folder" ]]; then
            mkdir -p "$folder"
            mv "$file" "$folder/"
            echo "Moved $file to $folder/"
        fi
    fi
done

This script:

Checks if an item is a file
Extracts the file extension and normalizes it to lowercase
Finds a matching folder from the mapping
Creates the folder if it doesn’t exist and moves the file

Using mkdir -p ensures the destination directory is created only if it doesn’t already exist. This design is both safe and efficient.

5. Enhancing with Logging and Dry Run

To make the script safer and more usable, consider these enhancements:

dry_run=false

# Use -d for dry-run mode
while getopts ":d" opt; do
  case ${opt} in
    d )
      dry_run=true
      ;;
  esac
done

for file in *; do
    if [[ -f "$file" ]]; then
        ext="${file##*.}"
        ext_lower=$(echo "$ext" | tr '[:upper:]' '[:lower:]')
        folder=${EXTENSIONS[$ext_lower]}

        if [[ -n "$folder" ]]; then
            mkdir -p "$folder"
            if $dry_run; then
                echo "[Dry-run] Would move $file to $folder/"
            else
                mv "$file" "$folder/"
                echo "Moved $file to $folder/"
            fi
        fi
    fi

Now running ./organize.sh -d won’t actually move any files but will show how they would be organized. This is great for testing before making changes.

6. Performance and Tips

Some best practices to keep things smooth:

Use cron: Automate this script using cron to run every hour or once daily.
Handle duplicates: Consider renaming duplicates if the destination file already exists.
Use find or inotify: For recursive or real-time watching in large directories.
Logging: Redirect output to a log file: ./organize.sh >> organize.log 2>&1

7. Making It Global

If you frequently use this script, add it to your /usr/local/bin/ and make it executable:

sudo cp organize.sh /usr/local/bin/organize
sudo chmod +x /usr/local/bin/organize

Now you can run organize from any directory.

Conclusion

Automating file organization with Bash is not only a satisfying task but a real productivity booster. With a minimal investment of time, you end up with clean directories, sorted archives, and a process you can tweak or enhance as needed. Whether you’re managing log files, screenshots, documents, or media, a simple Bash script can save you hours in the long run.

Try adapting this pattern by file size, date, or keywords in the filename for more custom workflows. This script lays the foundation for powerful local automation using just the Bash shell.

Useful links: