Mastering File Renaming in Ruby

Mastering file manipulation is crucial for any developer, and Ruby offers elegant solutions for renaming files efficiently. This guide explores various techniques, from single-file renames to complex batch operations across directories.

Table of Contents

• Why Rename Files Programmatically?
• Renaming a Single File
• Renaming Files in the Same Directory
• Renaming Files Recursively Across Subdirectories
• Batch Renaming Files with Custom Logic
• Robust Error Handling

Why Rename Files Programmatically?

Manual file renaming becomes impractical when dealing with numerous files. Automation offers several advantages:

• Efficiency: Process hundreds or thousands of files quickly and accurately.
• Standardization: Enforce consistent naming conventions for improved organization.
• Version Control: Append timestamps or version numbers to track file iterations.
• Workflow Integration: Seamlessly integrate file renaming into larger data processing pipelines.
• Data Cleanup: Correct typos, remove unwanted characters, and enhance searchability.

Renaming a Single File

The simplest scenario involves renaming a single file. Ruby’s File.rename method handles this directly:

old_path = "/path/to/old_file.txt"
new_path = "/path/to/new_file.txt"

begin
  File.rename(old_path, new_path)
  puts "File renamed successfully!"
rescue Errno::ENOENT
  puts "Error: File '#{old_path}' not found."
rescue Errno::EEXIST
  puts "Error: File '#{new_path}' already exists."
rescue => e
  puts "An error occurred: #{e.message}"
end

Renaming Files in the Same Directory

To rename multiple files within the same directory, use Dir.glob to select files matching a pattern:

directory = "/path/to/files"
pattern = "*.txt"

Dir.glob("#{directory}/#{pattern}") do |file|
  new_filename = file.gsub(/.txt$/, "_modified.txt") #Example renaming logic
  begin
    File.rename(file, new_filename)
    puts "Renamed: #{file} -> #{new_filename}"
  rescue => e
    puts "Error renaming #{file}: #{e.message}"
  end
end

Renaming Files Recursively Across Subdirectories

For renaming files across subdirectories, use the `**` wildcard with `Dir.glob`:

directory = "/path/to/files"
pattern = "*.txt"

Dir.glob("#{directory}/**/#{pattern}") do |file|
  new_filename = file.gsub(/.txt$/, "_modified.txt")
  begin
    File.rename(file, new_filename)
    puts "Renamed: #{file} -> #{new_filename}"
  rescue => e
    puts "Error renaming #{file}: #{e.message}"
  end
end

Batch Renaming Files with Custom Logic

For more complex scenarios, use a hash to map old filenames to new filenames:

directory = "/path/to/files"
renames = {
  "file1.txt" => "new_file1.txt",
  "file2.jpg" => "new_file2.jpg"
}

renames.each do |old_name, new_name|
  old_path = File.join(directory, old_name)
  new_path = File.join(directory, new_name)
  begin
    File.rename(old_path, new_path)
    puts "Renamed: #{old_path} -> #{new_path}"
  rescue => e
    puts "Error renaming #{old_path}: #{e.message}"
  end
end

Robust Error Handling

Always include comprehensive error handling to gracefully manage issues like files not found or existing files.